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need help to write code for 8051

2009-01-08T08:57:15-08:00

thank u very much mr pundalik a.k.a. pdi33. u have given me a great pleasure to mail and guide me to use the site. i love electronics, i always experiment with new technology as right now i am working in media designing pipe line for post production studios in orissa. whenever i find time i do make myself busy with electronics. that give me energy. i may be old physically but i am very young mentally. god bless u all people. i am very happy to say u all r helping other people by guiding properly without anything, that's a great & noble idea. any way i am working on a object counter project. i can make the counter Hardware using discrete ics but i want it on uc as it can be don with less components. i can write code for a single digit counter using a switch as input , 7seg display as display. i don't know how it can covert to multiple digits, i want the device should count up to 9999 , all the display should be multiplexed. a switch can be used as input in every press of the switch the counter has to increment by 1, when it reaches 9999 it has to stop. then restart again by another sw press. i am sorry fora lengthy mail .thanks all agains.k.sahoo

Re: need help to write code for 8051

1nafar — 2009-01-08T08:57:15-08:00

hiyou can download the project from linki write this code with bascom8051 and change to asm for you http://www.2shared.com/file/3955362/782373c3/project.htmlcan you download from 2shared?bay

Re: need help to write code for 8051

Ajay — 2009-01-08T08:57:15-08:00

Hi sks, welcome to website We all try to do our best. And Hope you learn a lot from here Please keep 1nafar's code as reference, i suggest you to try it on your own so that it helps you better way. If you have any doubt doesnt matter small or big simply post here.

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

btw, i checked the simulation file of nafar and it seems to be a time counter(timer) instead of object counter. So u will have to do a little modifications i the ciruit provided by him especially about intrducing the opto coupler part as u had referred to it in the chat box description ( if remember correctly).for the optocoupler, i suggest u use the simplest one which is the TL817 4pin opto.u can refer in the download section for 7 segment interfacing circuit ( u will require multiplexed one for ur project .)try finalising the circuit first before starting coding.good luck,regards, P.S.: another important aspect for object counting (if u r going to use it in a practical application in future) is the storage of the last count on power failure so that u can continue from the last count onwards. Please confirm whether that condition is required for ur apliction and i can suggest u a solution for it.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Mr pdi33, thank u for ur reply, comments, and queries. yes Inafar's project is a time counter i had simulated in Proteus i can modify the circuit and post. u have said correctly i have to store data in external memory if power fails or for other reasons. i think a 24c04 will solve the problem i don't know what u suggest. actually it is a practical project i will use a 4*4 matrix key pad to input the required base value. when i start the hardware all 4 display has to be in off mode , i may enter any value like 0000, 34 or 100 in hex keypad which has to be displayed after that i have to press an enter key which will be a part of hex keypad to start the counter it has to count above the entered value and stops at 9999. Mr Ajay has advised me to follow Inafar's code but i could not follow his code, i want to learn pl help me from ALGO to CODE writing. i know it may be a hard task for u but if u can pl guide me young man. i don't know what u do, do u have time or not. pl reply. thank againsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Mr ExperimenterUK,thanks for your comments, i am glad that u people are watching the forum and helping others. i am a learner, pl don't mind if write some odd things.thanks again.sks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Thanks Ajay, i have inafar's project file there was Proteus project file along with codes written in basic ,hex file and a list file etc . i have simulated that in Proteus, it is a time counter. ok whatever it may be i had followed his source code in the list file but sorry to say i couldn't follow completely as it doesn't have comments. as i have said i am new to uc i will love to know in details like how u people write algorithms and the codes. please guide. thanks agains.k.s

Re: need help to write code for 8051

ExperimenterUK — 2009-01-08T08:57:15-08:00

Hello sksAs Arun says the best place to start is with a good book,(or several good books) and simple experiments.Trying to understand someone else's code, without good commenting is very hard.I wouldn't bother, you'll just get a headache Good luck anyway.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Mr ajay, sorry to disturb u people, but i want to learn programming. i have followed the code of Mr Inafar but it is hard to understand on part fully.let us go slowly, i have some questions 1: if we write ORG 00H is it reset all and goes to starting of all locations or starting of only memory location ?2: if we write ORG 0BH is it reset time counter0 ?3: i don't follow this ORG 33H, 36H is it starting of (general purpose) scratch pad location of internal RAM?4: in line x004b he has written mov 20h,#0 is it decimal 0 will be loaded at bit addressable location of RAMI don't know uc language correctly i am trying to learn, i write very small codes. i have never used interrupt or counter of 8051, some people write delay routine using timer but i write delay routine using LOOP technique.i will appreciate if u help me to complete this project. thanking you once again. i am sorry but i want to learnsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Mr 1nafar, thank u for ur help. i am glad to know u have taken pain to disassemble the code and mail me to help me out. god bless u people, but i could not follow completely as there are no comments and subroutine names i don't know what u call it (x0036). if u want to help me pl send me the ALGORITHM of ur code by which i will try to understand it. u have used direct bit addressable method and used interrupts i am not used to it as i am starting learning recently. thanks againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

hello SKS, we respect your interest and appreciate your Zeal to learn Micros. please don't be in a hurry, my advice would be to first get hold of a good micro book like Kenneth Ayala or mazidi and soak you self into the basics of code building, try some small projects to familiarize with concepts and then move on to more complex projects.Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,Thanks for ur advice. I have purchased a book of kenneth j ayala today . pl guide me should i read it from Numbering Systems and Binary Arithmetic or i should start from ch3 The 8051 Architecture onwards. actually i will love to learn while doing a project. i have written some codes, if u allow me i will glad to send or post to u for ur comments.thankssks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hi pdi33,thank u for ur guidance. let me study first. pl don't forget to help me whenever i need.s.k.s

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

sks,nobody is perfect, sir . we are all learners. As for the books part, i think u should start with numbering system if u are not familiar with it. In 8051, we usually encounter lack of data RAM space if we do not use variable lengths properly. So, better understand the basics of father of all languages "mathematics" before proceeding any further .

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hi Mr Ajay,i am sks here, i have received 3 mails send by you. Thanks for that, pl guide me shall i send my queries through this quick reply window or mail from my mail id because the reply a got here itself the same in my mail. it confuses me.i am using 8051IDE for simulation of my code what i am witting now is it OK.pl guide me Thanks againsks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

hi sks,when u start a new thread, there is an option below the post window:"If you wish to be notified by email when a reply is posted to your thread please tick the box" by default the box is ticked. So whenever any member writes a new post in ur thread, u are automatically notified via e-mail sent in the admins name. So,u can ignore the mail as long as u are up to date with ur thread progress . In future, if u do not want the notification, just uncheck the box before creating a new thread.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

thank u pdisks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Mr pdi33,i have written a counter program, if u allow me i want to send the same to u for ur comments and to identify my mistakes.thankssks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

sks,u need not ask for it, just attach the code along with ur post.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hi pdi,i don't know how 2 attach a file. pl guide. i am pasting my code here itself,please don't mind. it is a up counter 0 t0 99. pl check and comment.thankssks;simple 0 to 9 Hex counter;hex value will be shown at p1,p2;written by sks org 00h ;reset all mov r2,#90 ;load decimal 99-9 in r2 for total countstart: mov r0,#00h ; clear r0 mov r1,#00h ; clear r1 mov p1,#00h ;p1=0 mov p2,#00h ;p2=0count: mov r0,a ;r0=a=0 inc r0 ;r0=r0+1 in every count mov a,r0 ;a=r0 (incremented value) mov p1,a ;p1=a dec r2 ;r2=90-1 in every count cjne r0,#9h,count ;if r0 not equal to 9 go to count else move to next line acall tc_loop clr a ;a=0 inc r1 ;r1=r1+1 in every count mov a,r1 ;a=r2 (incremented value) mov p2,a ;p2=a mov p1,#00h ;p1=0 clr a ;a=0 cjne r1,#10,count ;if r0 not equal to 10 go to count else move to next linetc_loop: cjne r2,#0,tc_end ;if r2=0 stop counting ajmp end tc_end: retend: end

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello sahooji,Good to see that you are putting efforts in writing your own code !the above code has many errors, i think you are trying two or three things at a time, if you want to display count in hex then you can display it on only one port but you are thinking of displaying the count like on two 7-seg displays.you can display upto 255 (FFh) on one 8 bit port.if it is a up counter then you should increment the register/variable, but you are incrementing r1 and decrementing r2.CODE:
ajmp end
tc_end:
ret
end:
end the above, is a common newbie mistake. instruction "end" does not belong to 8051's instruction set but it is an assembler directive, it tells/indicates the assembler the "finish" of code. its the job of the programmer to " loop back " other wise the micro fetches and executes the code till the end of ROM memory and resets it self .in my earlier post i had suggested you to go thru a good micro book (kenneth ayala) but seems that you have not spend enough time with the book. i / we can understand your enthusiasm to learn micros but keep in mind "good foundation is a must for becoming successful designer" you can read the topic "PAL" (Practice Assemble Language ) in ayala's book.Arun

Re: need help to write code for 8051

Ajay — 2009-01-08T08:57:15-08:00

end is a keyword in keil (if you are using keil) so replace it with any other label say "routine_end" or something.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Arun,thank u for ur comments and advice. as per ur advice believe me i m reading the said book. as mr pdi33 had suggested to read from the numeric system, i m following his advice. i know there must be errors in my code as i hv told b4 i m new to ur world of uc. so pl bear with me, i promise u i will try to obey ur advice and follow ur said path. pl try to point out the errors. i wrote the code for two 7seg displays, it will count 0 to 99 and stop when counter reaches 99. of course i hv not written delay for above code.thanks againsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Ajay,thanks for ur suggestion, i am using 8051 IDE not KEIL. pl suggestsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Arun,first allow me to call/address at least u as "SIR" among all of ur Moderators.last night i hv gone through the chapter PAL of the book, and felt sorry for my mistakes. it was not a structured one, no algorithm has been followed etc.ok i will try to improve myself. pl reply. thanks againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello sahooji,you don't have to call me or our friends as SIR, on the contrary we have to call you as SIR, because of your age, we are like your kids - so no formalities !regarding PAL, pl. go thru that chapter carefully, the author has explained the concept very beautifully and this is the first step to be learned before actual 8051 assembly.did you know that 8051 which is a 8 bit micro, actually has a instruction set of 255 instructions/commands (FFh) - thats how amazing our 8051 is !Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,i hv some doubts in PAL Practice Chapter. It has been written PAL has only NINE Instructions where as we hv 255 instructions to use. pl clear my doubt.one more question, i have notice in Instruction set there r 8 AJMPs 7 ACALLs having different OP CODES, why it is like that. pl clarify my doubts.thanking usks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,Thank u all, i extremely happy after reading ur reply. god bless u all. i didn't know there is 255 instructions before, i didn't notice that op code part of instructions in the book. right now i noticed it , it is 255 (ffh) nos. thanks for teaching me. i have followed some of ur replies in other threads, it is amazing. i mean ur teaching style. thank u all againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

hello Sahooji, please don't get confused with the PAL instruction set and 8051 instruction set, the author introduces the concept of Assembly language by taking example of a "similar" micro controller like 8051 and names it as PAL micro controller just like we have 8051 Micro.now PAL micro has RAM, Registers, ROM, PC etc just like any 8 bit micro, it also has separate instruction set, opcodes ( just like 8051). now this typical PAL micro has only 9 instructions or opcodes,and the author wants us to understand the concept with the help of a small micro rather than straight away starting with bigger 8051.regarding the different no:of opcodes for AJMP and ACALL, each opcode is a result of possible short address 3 bit combination(upper bits).at this stage you don't have to worry about this.Arun

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello Sahuji,Nice effort !your 255 counter seems OK, but what happens after the counter has reached 255 ?and coming to 1000 counter, why are you using DPTR, R registers ( 2 of them ) and Acc.just follow your first 255 counter (now make it 250 counter) and increment a register after completion of 250 counts , do this 4 times and you have a 1000 counter.one more thing, after execution of your said task, you have to define the state of Micro i,e should it continue repeating same task (looping) or just stay at particular address.Pl.note : your counter/s need external or internal "trigger" to increment the count(can be a pulse from external circuit, a switch, or internal timer)Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,i hv written two simple up counter code, one can count up to 255 and another can count up to 1000. the later one was little difficult to write. is this one of the ways to count up to 1000 or more. i am pasting the codes here. pl comment, how can i know my faults, unless i see the correct one.thanks allsks; 0 TO 255 DEC COUNTER ORG 00H MOV A,#0MAIN: INC A CJNE A,#255,MAIN END; 0 TO 1000 DEC COUNTER ORG 00H MOV A,#0 MOV R0,#0 MOV R6,#0MAIN: INC DPTR MOV A,DPL CJNE A,#250,MAIN MAIN_1: INC R6 MOV DPTR,#0000H INC DPTR MOV A,#DPL MOV R0,A CJNE R0,#4,MAIN END

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Mr Arun,Sorry.... i hv forgot to inform u that, i know how to trigger from out side, but don't how to trigger internally. don't know any thing about Timer & Interrupts. pl helpsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,thanks fr the quick response. as per ur advice i hv modified those two codes, which are pasted bellow. pl see and comment.thanks again.sks; 0 TO 255 DEC COUNTER;A Push Button Switch is connected to P3.0, and when the button;is pressed it start counting. After reaching 255 counts ;the counter resets and starts from begin. ORG 00H BEGIN: SETB P3.0 MOV A,#0PB: JB p3.0,PBMAIN: INC A CJNE A,#255,MAIN AJMP BEGIN END; 0 TO 1000 DEC COUNTER ORG 00HBEGIN: MOV A,#0 MOV R6,#0MAIN: INC A CJNE A,#250,MAIN MAIN_1: INC R6 CJNE R6,#4,MAIN AJMP BEGIN END

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello sahuji,i have revised (optimised) your 255 counter code, pl.go thru it and your assignment is to revise your 1000 counter on similar lines CODE:ORG 0000H

MAIN: MOV P1,#0FFH
MOV A,#0

PB:SETB P3.0
JB P3.0,PB

PP: JNB P3.0,PP ; THIS INSTR. IS TO COPE WITH SWITCH DEBOUNCE
CJNE A,#255D,GO ; CHECK IF COUNT IS ALREADY 255,
MOV A,#00H
SJMP PB

GO: INC A
MOV P1,A ; DISPLAY COUNT ON PORT 1 IN BINARY USING 8 LEDS
SJMP PB

END
timers is a vast subject and you need to take your time to learn about them, it better you complete your preliminary exercises before understanding about timers.Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr pdi,how r u. r u observing my progress guided by Mr Arun. write some thing to me, u people r so nice.thankssks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,Nice to see my Code modified by you, thank u. I have studied the modified code, is it every ACTION should follow a DECISION or every DECISION should follow an ACTION?. u hv assigned me to revise my 1000 counter code, (Now i am sure I can write codes of course by your help) i hv a doubt how can i connect leds in a single port which can display max 255/ffh. shall i display in BCD form? pl clarify.thanks againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello sahuji,in my/our above code, the counter advances after you press and release a switch, so for each increment you have to press and leave the switch.now for the decision or action part, first we have a action (i,e a key press) and then we have a decision (checking if the count is already 255,if yes restart the counter and if no, increment the counter and display on port)initially you'll have to display on port using 8 leds connected like this:and switch like this:later on, you have to convert the hex count to 3 digit BCD and display on 7 seg displays.BTW have you started working on your trainer board ?Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Arun,thanks fr the fast reply, yes i am using one NSK 8051 kit. i had tested one of my counter code through 8 nos led. it works, but sorry to inform u that that kit don't have BCD to 7seg converter chip, all 7seg data lines are parallel and separate com pins are connected through Transistors. i can write for single digit of course it may not be fully correct. it can count up to 9. what do u mean BTW. thanks againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

its good that your trainer kit doesn't have Binary to BCD ic 4511, otherwise it would be very easy.now the set up you have on your trainer is called "Multiplex display", you can look up on this concept in ayala's book (since you are already referring to it).meaning of BTW is "By The Way"Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr pdi,good morning, ur reply is highly appreciated. thank u very much. i love all of u people, and have high respect to ur knowledge. ( i mean all of ur knowledge). god bless u all. thanks again.sks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

sks wrote ...Hello Mr pdi,how r u. r u observing my progress guided by Mr Arun. write some thing to me, u people r so nice.thanksskshello sks,yes, i am observing ur progress and u are surely progressing very well ( just as i expected! ).u are being guided by arun, one of the best programmers, so be sure to learn as much from him as u can. . We all are here to support u and it would be wiser to let one of us guide u at a time instead of too many suggestions being bombarded into ur direction totally confusing u. .at this rate, i don't think it would be very long for u to complete ur project.good luck.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,good morning, thank u for giving a valuable cue. i came to office with problems in mind to ask u, request u to give me cue. when i open the site and read ur answer u won't believe how happy i am right now. please give me a day to compete my 9999 counter code. i don't follow "your trainer kit doesn't have Binary to BCD ic 4511, otherwise it would be very easy". i don't know how i can display 3Digits from a single port with out multiplexing. we will discuss this issue latter on. i will submit the code tomorrow. thanks againsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,i have tried to write the code as per my knowledge and getting cue from u. i don't think this will satisfy you. how ever i have completed the code & couldn't wait to test in my kit. i thought i will show u first. pl see and comment. thankssks;4digit multiplexed 9999 counter org 0000h mov r0,#00h mov r1,#00h mov r2,#00h mov r3,#00hmain: mov p1,#03fh mov p2,#0fhpb: setb p3.0 jb p3.0,pbpp: jnb p3.0,ppone: inc r0 mov a,r0 call digit_1 cjne r0,#09h,pb mov r0,#00h mov p1,#3fhten: inc r1 mov a,r1 call digit_2 cjne r1,#09h,pb mov r1,#00h mov p1,#3fhhundred: inc r2 mov a,r2 call digit_3 cjne r2,#09h,pb mov r2,#00h mov p1,#3fhthousand: inc r3 mov a,r3 call digit_4 cjne r3,#09h,pb mov r3,#00h sjmp maindigit_1: clr p2.1 clr p2.2 clr p2.3 call display mov p1,a setb p2.0 clr a call delay retdigit_2: clr p2.0 clr p2.2 clr p2.3 call display mov p1,a setb p2.1 clr a call delay retdigit_3: clr p2.0 clr p2.1 clr p2.3 call display mov p1,a setb p2.2 clr a call delay retdigit_4: clr p2.0 clr p2.1 clr p2.2 call display mov p1,a setb p2.3 clr a call delay retdisplay: cjne a,#01h,two mov a,#06h rettwo: cjne a,#02h,three mov a,#5bh retthree: cjne a,#03h,four mov a,#4fh retfour: cjne a,#04h,five mov a,#66h retfive: cjne a,#05h,six mov a,#6dh retsix: cjne a,#06h,seven mov a,#7dh retseven: cjne a,#07h,eight mov a,#07h reteight: cjne a,#08h,nine mov a,#7fh retnine: cjne a,#09h,zero mov a,#67h retzero: mov a,3fh retdelay: mov r5,#1d_loop1: mov r6,#25d_loop2: mov r7,#100loop: djnz r7,$ djnz r5,d_loop2 djnz r6,d_loop1 ret end

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

change this error (commented previous statement): CODE:
d_loop1:
mov r6,#25

d_loop2:
mov r7,#100

loop:
djnz r7,$
djnz r6,d_loop2 ;djnz r5,d_loop2
djnz r5, d_loop1 ;djnz r6,d_loop1
ret
end
will add in this post if i find any other logical error

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

@ pdi, thanks for your comments ! sahuji, congrats!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! you have done it !have you tried the code on your trainer ? if not try it and observe what the display does.if you go thru the logic of your code, you are resetting the counters on count 9, why ?and also the second digit will only be displayed if the first digit is 9 ( this applies to all other digits)a lot more tweaking is needed in the above code. especially the display part.and yes, you can use Binary to BCD cmos ic 4511( 4 of them) to display 4 digits without multiplexing. there is a enable(store) pin on 4511 which can used to latch the data for a particular digit. and you'll be using only 8 port pins to interface 4 digits ( 4 pins for binary input and 4 for enable)Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hi pdi,we want a delay of 25/30 mSec fr multiplexing , am i right?i hav tried to write the delay routine by following some other delay code.actually i will love to know the fundamental of delay subroutine code writing, i want to use internal timer, but i don't know. i will modify what u hav suggested. thanks again and good night.sks

Re: need help to write code for 8051

Ajay — 2009-01-08T08:57:15-08:00

well, basics of timer is as follows:Timer are a kind of counter which counts clock cycles. Duration of clock cycle depends on your external clock. When this counter overflows or say counts till maximum and then rolls back to zero, an interrupt is generated or flag is raised to indicate overflow has occurred.Now Incase of 8051, clock cycle = Fosc/12so time for single clock = 12/FoscLets say you are using 12Mhz clock, so duration for single clock is 12/12 = 1uSwhich means for every increment in timer count, a delay of 1uS is generated.If timer is 16-bit then total delay generated for single overflow (from 0 to 65535) is 65.535mSIf you want delay of 50mS (50000uS) then you just have to count 50,000 times.timer has to be loaded with -50000 = 0x3CB0 (use windows calculator)THx = 0x3CTLx = 0xB0x can be 1 or 0 depending on timer used.so when overflow occurs, you get interrupt or poll for TFx to go high, it means 50mS overHope timers are clear to you now

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,good morning. i just can't express my happiness. tears r coming from my eyes. u believe me. how great u people r. ok i couldn't test the code in my kit due to power failure. i had to come my office for duty. so sorry i will test to night & let u know the result tomorrow. sorry for the late. after this is completed i will try with BCD code. thanks a lot.sks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Ajay,good morning. thank u. now i understand the logic u have described. there r two timers in 8051 right? so i can write TH1 & TL1 right?, pl describe about "If timer is 16-bit". i think i should read the TIMER Chapter in my book & ask.thanks all.sks

Re: need help to write code for 8051

Ajay — 2009-01-08T08:57:15-08:00

yes TH1 and TL1 for timer 1 and TH0 and TL0 for timer 0.you must read about timers in your book, if you want recommendation, then go through 8051 User manual from Intel. Best guide to learn 8051.search in google, its free to download.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,good morning, ha.... its a 0 to 9 counter in display. i have tested in my kit. "KHODA PAHAD NIKLA CHUHA". i don't know where the fault lies. as u have indicated why"cjne r0/r1/r2,#09h". i will reanalyze this and let u know. i could not find any errors in display, there must be errors as u r saying. it will be great help if give some cue, i will try to correct my fault.thankssks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Ajay,good morning. thanks for the suggestion to download INTEL8051 file. last night i referred my book but couldn't understood completely, i hv to reread that chapter again & let u know what i learned.thanks againsks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

Ajay wrote ...you must read about timers in your book, if you want recommendation, then go through 8051 User manual from Intel. Best guide to learn 8051.Aaaahhhh. ... that was the first book i referred for the 8051 ( back in 1997!) . unfortunately, internet was not accesible easily those days and this book ( hardcopy) was the only reference I had to learn this micro.'Poorani Yaadien Taaza ho Gayi' .

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arunsorry i couldn't solve the problem. i can't count 9999 dec using single register right. so i hv used 4 registers each will count up to 9 ,when 1st register reaches 9 the second register has to starts counting displaying "0" in ist displaywhen 2nd register is reaches 9 third register will start counting. pl help by solving the problem. thankssks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

sks wrote ...Hello Mr Arunsorry i couldn't solve the problem. i can't count 9999 dec using single register right. so i hv used 4 registers each will count up to 9 ,when 1st register reaches 9 the second register has to starts counting displaying "0" in ist displaywhen 2nd register is reaches 9 third register will start counting. pl help by solving the problem. thanksskssks,u can use only two registers to count 9999 counts.For that u need to use the 'DA A' instruction .U can study that later and implement it .But for now, this logic seems fine. From ur previous post i have a little confusion. Did u mean that u could display only one digit or that the kit displayed all digits but only the last digit counted from 0 to 9?

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,good morning, r u in holiday? i hv attached our modified code in my thread. pl see and give comments. thanks againsks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

nice work sir,it feels really heartening to see people like u who r really clear and committed to their goals and i have experienced that success seldom eludes such people.hope u bring back some good news tommorow. o.k. let me give u a hint. the routine given below can count upto 9999 counts (one count at a time)if u did not follow the logic , ignore it and try completing ur project. U can always get to it later to optimise ur code. counts are in r1(Most Significant Digit) and r2 in decimal CODE:
clr c
mov a ,r2
add a,#01h
da a
mov r2,a
mov r1,a
addc a,#00h
da a
mov r1,a
the logic is that the 'da a' combined by the previous add instruction performs one byte decimal addition.if the count exceeds 99 , the carry flag is set and the accumulator is reset to 00. this carry flag is then added to the MSD.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello pdi,good morning, thanks for the reply. there was a display problem in my code. when i reset my kit all four digits displays 0000, when i press the pb for count, it starts counting in every press up to 9. any way i hv modified my code & here is for ur comments. of course i hv nt tested this modified code in my kit. thanks again.sksCODE:;4digit multiplexed 9999 counter org 0000h mov r0,#00h mov r1,#00h mov r2,#00h mov r3,#00h clr astart: mov p1,#03fh mov p2,#0fhpb: setb p3.0 jb p3.0,pbpp: jnb p3.0,ppmain: inc r0 call display cjne r0,#0ah,pb mov r0,#00h inc r1 call display cjne r1,#0ah,pb mov r1,#00h inc r2 call display cjne r2,#0ah,pb mov r2,#00h inc r3 call display cjne r3,#09h,pb mov r3,#00h sjmp startdisplay: clr p2.1 clr p2.2 clr p2.3 mov a,r0 call convert mov p1,a setb p2.0 call delay clr p2.0 clr p2.2 clr p2.3 mov a,r1 call convert mov p1,a setb p2.1 call delay clr p2.0 clr p2.1 clr p2.3 mov a,r2 call convert mov p1,a setb p2.2 call delay clr p2.0 clr p2.1 clr p2.2 mov a,r3 call convert mov p1,a setb p2.3 call delay convert:one: cjne a,#01h,two mov a,#06h rettwo: cjne a,#02h,three mov a,#5bh retthree: cjne a,#03h,four mov a,#4fh retfour: cjne a,#04h,five mov a,#66h retfive: cjne a,#05h,six mov a,#6dh retsix: cjne a,#06h,seven mov a,#7dh retseven: cjne a,#07h,eight mov a,#07h reteight: cjne a,#08h,nine mov a,#7fh retnine: cjne a,#09h,ten mov a,#67h retten: cjne a,#00h,zerozero: mov a,#3fh retdelay: mov r5,#1d_loop1: mov r6,#25d_loop2: mov r7,#100loop: djnz r7,$ djnz r6,d_loop2 djnz r5,d_loop1 ret end

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

hi sks,ur modified code looks pretty good. Try it out and check if it is giving right output.good luck.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hi pdi,thanks for ur comments. actually i modified the code today morning, so i couldn't find time to check in my kit. i will try it out & let u know tomorrow.thanks againsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello pdi,good morning. sorry, u know what i say. thank u fr ur suggestions, what u hv suggested is little higher technique, i will follow latter. right now u r my friend and Mr ARUN is my teacher. i will follow his advice only. sorry don't think otherwise.we will chat at 6. thanks again.sks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello Sahuji, No, i am not on a holiday, just have been busy with a jumbo project which we are doing for RBI in Mysore ( Rs. 2 crore project) its a security related project.O.K, now you are on right track, you are resetting on 10d the count, good job !one more thing, pl. test your code/s on the trainer kit before posting here, bcoz you'll know how the program works "First Hand" and you can modify the code after its working on trainer. i would suggest not to follow pdi's method at this stage, just do your thing and follow your algorithm ( sorry pdi, didn't want to confuse sahuji at this level -hope you'd understand)Arun

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

Arun Kumar V wrote ... i would suggest not to follow pdi's method at this stage, just do your thing and follow your algorithm ( sorry pdi, didn't want to confuse sahuji at this level -hope you'd understand)Arunit is perfectly fine bro. Actually, i wrote the code as sks requested for any method to optimise the code. If u read my post completely and chat box comments u will see that i have already reflected the same thoghts.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arungood morning. thanks fr ur comments and suggestions. from today i will check my code in my kit first then post. i am really sorry to say that pdi was n't suggesting any thing, i requested him to comment, its my fault not his. i am sorry fr that. i could copy others code or ask u people to write the code fr me which would solve my problem, but u know i want to learn from u people. i may talk to any body but i will follow ur advice only right now (what pdi had suggested). ok i have checked the code in my kit, found some how correct. the counter is all right, but there is problem in the DISPLAY part. when i start the kit all zeros are at all displays, when i press the pb to count, only one display shows and count till 9 after that 2nd display shows 1 & off, after that ist display shows and count. if i in put a 30 hz signal to port3.0 pin (in switch input) all display shows and count till 9999. is there any problem in delay sub routine or in program loop? pl give cue. sorry fr every thing.thank againsks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello sahuji, you don't have to feel sorry for anything, pl.don't be under the assumption that nobody is watching or following your progress, all our Mods & Admin are keeping an eye on every forum post being made - in fact even GOD is watching you learn micros on fast track ! any member is welcome to contribute/advice you on the subject, and your statement " i'll listen to Mr.Arun and not others " is inappropriate. to show we Mods and Admin are "ONE" i request our equally ( in fact more ) experienced Friend and super MOD Pdi33 to train you further from this stage.Over to you pdi33 bro !Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello SHYAM,happy to know that ur also s.k.s. i know how good u people are, how united you people are. you can feel my emotions and love by seeing my previous posts. i m a soft kind of person, here to learn from all of u young people. god bless u all.thankssks

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

hi sks,u got the same initials as me ! (S.K.S).now you see in this forum everybody share there experience and thoughts...but the best thing is everybody is like minded with a single moto.. lets find the solution..you keep on working on your project and keep posting the doubts here.. somebody will always be there to guide you.. the others are not here to contradict anybody...but they will certainly provide an addon that wud help u a bit more.as Arun said we are one..so listen carefully to all comments and then let us know what you have grabbed from them!....all the best !!!

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello Mr Arun,u believe me i have all regards and respect to all of u people even if u all r much younger than me. i am sorry if i hv used some wrong words. do u believe my educational qualification is HSC passed at that time, i am nt well versed in English. any way i am here to learn. i always bless YOU ALL forYOUR prosperity in life. i hv traveled a long way by grace of GOD and LOVE given by young people like u all. God is there to help them who helps others.thanks allsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun,thank u for the post. yes u hav already explaind about DS 1. sorry fr my ignorance. i was confused for that lebel "COUNT: DS 1". ok thanks allsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello every body,plzzzzzzz see my code and solve my problem, i hv described the problem in my last post. please helpthanks allsks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

Arun Kumar V wrote ...to show we Mods and Admin are "ONE" i request our equally ( in fact more ) experienced Friend and super MOD Pdi33 to train you further from this stage.Over to you pdi33 bro !Arunthanks arun,actually i feel u r the right person for the job ( as a teacher) as rightly put by sks. I was only suggesting a few ideas ( for the future) as u were not available at that time. sharing programming experience and teaching the basics are two different things altogether and i feel (honestly!) u are very good at both which in itself is a rare quality and i respect that. BTW, Best wishes for ur project u mentioned. Hope it completes successfully without any hiccups.@ sks,the comments u placed in ur previous post ( about not following my logic) is not offending and has been taken by me in the correct meaning so u need not feel sorry for it. We as a team are always there for people like u who are sincere and committed enough in learning .hmmmm..... now coming to ur problem , The major difference between displaying data in an LED display and and LCD display is that, u have to continuously scan the multiplexed LED display in the program flow but in an LCD display module, the scanning part is internally controlled and u only need to output the modified display data.So, coming to ur code,the display scanning takes place only when u have an input count( display is event controlled). This means that if ur hardware does not have any input pulse, the uC will stop scanning and output only the last data ( which is ur last display, digit4). So only the last display was showing the data. In ur second condition mentioned( giving a 30hZ pulse input), u were giving a continous input thus updating the display at the rate of the input pulse. So the display was being correctly represented.what u have to modify in the code is that u have to separate the displaying( scanning) part from the counter increment part and execute the display scanning part continuously( time driven and not event driven) irrespective of the input pulse event. The input pulse event should be used only to increment the counter and not drive the display. hope u understood the problem.P.S. sks, I know sometimes we get really impatient when things don't work out and we run into a complete roadblock. but try to understand that all of us too are having other jobs to handle and it would sometimes occur that none of us are there to guide u at the required moment.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello pdi,good morning. happy dussahara. thank u for ur guidance & help. i modified the code as u have suggested. tested in my kit last night. it is ALL RIGHT now, all three displays are showing there respective count values. but one problem is still there. as long as i press the push button switch (not released state) only one display is showing it's count value, after releasing the switch all displays are showing there values. one thing i want to know after modifying the code like this CODE:main:
call display
jb p3.0,main
jnb p3.0,main
inc r0why it didn't work?, when i omit the jnb part there was a debounce error (display was counting erratically). after changing the code like this CODE:
main:
call display
jb p3.0,main
jnb p3.0,$
call debounce
;
debounce:
mov r4,#0ffh
djnz r4,$
ret
it started working with the problem stated above. pl help me to correct the said error. And pl clarify where was/is the problem? thanks again.sks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello, pdi.thanks fr the reply. u hav told the right thing about my code. i m seriously trying to modify the code. i hv written a small LED blinker program using TIMER. i will thanks Mr AJAY here , he had described about Timer in his reply in previous post. before that i was completely in dark. i think i should travel little slow. what i am right now in code writing is due to you all nice people. how cloud i offend u? I PRAY GOD TO GIVE WELL HEATH, HAPPINESS & PROSPERITY TO ALL YOU. I WILL REMEMBER U ALL FOR ALL OF LIFE. i am saying this from core of my heart. I AM IN A JOINT FAMILY I KNOW WHAT UNIT IS. we r seventeen members in our family. THANKS ALL.Ok I missed one thing i wish MR ARUN a great success in his project. GOD BLESS ALL OF YOU. sks

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

no sir!its a healthy atmosphere here... we just took a liitle bit of time to thank each other! you are a liitle late... lol

Re: need help to write code for 8051

Ajay — 2009-01-08T08:57:15-08:00

anything wrong here?

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Shyam,good evening. sks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Ajay,Good evening. NO NOTHING IS WRONG HERE. thanks alls.k.s

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello every body,sks is here, pdi has detected my code is event driven, my problem will be solved if it will be time driven. i don't know how to write my program using Timer. i hav written a small code using timer thats a led blinker program. pl help.thanks allsks ORG 0000h MOV TMOD,#01h ;Timer0 16-bit Modeloop: MOV TH0,#0C3h MOV TL0,#50h ;For generating 0.05 Sec delay CLR p1.0 ;Turn ON LED SETB TR0 ; Start Timer 0 JNB TF0,$ ; Wait till Timer 0 overflows CLR TF0 ;Timer0 has overflowed clear the Flag CLR TR0 ;Stop Timer0 SETB p1.0 ;Turn OFF LED MOV TH0,#0C3h MOV TL0,#50h ;Reload Timer0 For generating 0.05 Sec delay SETB TR0 ; Start Timer 0 JNB TF0,$ ; Wait till Timer 0 overflows CLR TF0 ;Timer0 has overflowed clear the Flag CLR TR0 ;Stop Timer0 ajmp loop

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

i am not gud in assembly... cud help in c..but still u shud make a routine for delay and call it in ur main routine..like...CODE:
ORG 0000h

MOV TMOD,#01h ;Timer0 16-bit Mode

loop:

CLR p1.0 ;Turn ON LED

ACALL DELAY ;call delay function

SETB p1.0 ;Turn OFF LED
ACALL DELAY

ajmp loop

DELAY:
MOV TH0,#0C3h

MOV TL0,#50h ;Reload Timer0 For generating 0.05 Sec delay

SETB TR0 ; Start Timer 0

JNB TF0,$ ; Wait till Timer 0 overflows

CLR TF0 ;Timer0 has overflowed clear the Flag

CLR TR0 ;Stop Timer0
RET
END

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

this way u can write a number of small modules and call it one by one as per ur requirement...so first of all make your modules ready like u have done for delay..make your own code library and save them there..then in ur project call them when required..ex.CODE:
ORG 00
MAIN_LOOP:
ACALL MODULE1
ACALL MODULE2
ACALL MODULE3
...
...
;WRITE MODULE DEFINITIONS HERE
MODULE1:
;TELL MCU WHAT TO DO
RET ; DONT FORGET THIS INSTRUCTION
;OTHERWISE MCU WONT
; RETURN TO MAIN ROUTINE
MODULE1:
;TELL MCU WHAT TO DO
RET ; DONT FORGET THIS INSTRUCTION
; OTHERWISE MCU WONT
; RETURN TO MAIN ROUTINE
MODULE2:
;TELL MCU WHAT TO DO
RET ; DONT FORGET THIS INSTRUCTION
; OTHERWISE MCU WONT
; RETURN TO MAIN ROUTINE
MODULE3:
;TELL MCU WHAT TO DO
RET ; DONT FORGET THIS INSTRUCTION
; OTHERWISE MCU WONT
; RETURN TO MAIN ROUTINE
.......
.......
ENDhope that helps...Ajay is the best man as far as asm is concerned....

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello SHYAM,thanks fr answering me. i don't know C, and trying to learn assembly by all of u nice people & from ur site. thank usks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

hello shyam,thank u for ur guidance. i know Mr Arun, Mr Ajay and pdi r helping me a lot to learn of course they r very good in assembly. i am waiting for them to reply. u hav taught me a good thing by describing about modules. i will remember this. thanks againsks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Shyam,good morning. wish u a "HAPPY DASSUHARA". thank fr ur comment and advice. i will remember ur advice in future. "Mr Arun was right some body is watching for every body's progress and posts." i am extremely happy that i am a proud member/user of this great forum, and u all r helping me to learn.thanks all.sks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

hi sks,as shyam suggested, u can use the timer as a delay routine. try ur code on the kit and give feedback.As for ur original code, what i implied was that ur display scanning part should be continuous in real time and the event (counter input) driven part of the code should be used only for updating the data fed to the display. So the timer is not really neccesary for the part. u can just execute the display scanning part continuosly in the main loop irrespective of the counter input.e.g.main:call display ; the display scanning partjb input,mainjnb input,main;here write the code for incrementing the count and update the display.jmp main

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello pdi,good morning. thanks a lot. Now i understood ur logic. i will modify the code, test in my kit and inform u. HAPPY DASHAHARA to ALL. thanks againsks

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

hello sks,its good to see ur progress.the message below is just a general comment,might not be related with your current program.if u cud add comment to every line of your code snippet we would come to know why u r using that particular instruction.. plus it will be easier for you too to debug the problem..take a lookCODE:
main:
call display ;CALL DISPLAY
jb p3.0,main ;IF KEY PRESSED DISPLAY AGAIN
jnb p3.0,$ ;IF KEY RELEASED /NOT PRESSED
; WAIT HERE
call debounce ;CHECK KEY DEBOUNCE
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;FUNTION NAME : debounce
;ARG PASSED : NONE
;GLOBAL VARIABLE USED: NONE
;REGISTERS USED : R4
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
debounce:
mov r4,#0ffh ;UPDATE COUNTER VALUE IN R4
djnz r4,$ ;WAIT AND DECREMENT R4 TO ZERO
ret ;RETURN TO PARENT
This way writing code will be as easy as writing an essay in english

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi pdi,thanks for the reply. Happy VIJAYA DASHAMI. i will check the code tomorrow and will inform u. thanks.sks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

hi sks,the problem u are getting is logically correct.actually, the best way out for such a situation is to use an external interrupt to sense (increment the pulse) or alternatively use a internal timer interrupt to scan the display. But these methods can wait for now. just modify ur code as below to: main:call displayjb p3.0,mainrelease:call displayjnb p3.0,release...this will ensure that the routine display is called irrespective of the input pressed or released. Happy dussehra

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi pdi,good morning. u people (i mean all of you) have given me a DUSSEHRA gift by helping/guiding to compete the code. It's working fine. I hv tested in my kit last night. we hav many things to do in the code. First thing we hv to preset it.what we hv written is to start count again after the last count reaches 9999. i hv modified a little by replacing"JMP MAIN ; go to main"to "STAY:JMP STAY ;Loop around here"for stop counting and stay there till we reset the hardware. one problem i found in the code is when the last count reaches and stops the counter it is showing 0000. suppose i want a preset count like i want to count 3905, when the counter reaches 3905 it has to stay there. i hv thought a logic pl correct me if i m wrong. my logic is i will load 3905 in 4 registers (of course by using a key pad, i will learn latter on) and compare them with there respective values, when they reaches there values the counter stops there with proper display. one thing i want to know can i use GENERAL PURPOSE RAM for counting? please help by clarifying.thanks a lotsks

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

hi sks!congratulations for the achievement and a Happy Dussehra Sir!coming back to ur problem=> "PRESET counter"there are times when we need to build a counter that counts up or down upto a specific count!. The main requirement can be classified as 1. Fixed count value (values written in code )2. configurable count values (values fetched at run time).you are talking about the second type.still u have to choose between =>1. volatile set points (count values).2. non volatile set points (count values)in volatile set point method you need to feed ur mcu with the count value evry time u perform the count action (as suggested by ur self it can be fed by a kpd). because at the power shut down(device turned OFF it will resume from its default value and the set point value shall be deleted).in non-volatile set point method we use a non volatile memory (EEPROMS FLSH NVRAMs etc..) . they will store the set points even after the device has been powered off.If you want to go for the volatile method stated above you can use the RAM registers of your MCU cause they are volatile memories. they get erased as soon as the power is switched OFF!for the non volatile method you will have to interface a NON-volatile memory they come in various packages and size.. and we can discuss them at later stage.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Shyam,Thank u for the reply and describing things. thank u all for my achievement. it couldn't hav possible on my part to write code for uc without all of yours help and guidance. thanks again. there was a query by pdi in previous post which is written below."another important aspect for object counting (if u r going to use it in a practical application in future) is the storage of the last count on power failure so that u can continue from the last count onwards. Please confirm whether that condition is required for ur application and i can suggest u a solution for it."Now i will say i am going to use a NON VOLATILE MEMORY a EEPROM like 24c04/08 for storing the my preset data as well as last count data. my question was can we use general purpose ram instead of registers for temp counting and using registers for other purposes? ok pl let me know how i can attach/upload my CIRCUIT DIAGRAM or SCHEMATICS. One more thing u know ORISSA is popular for Handicrafts, filigree works and having a lot GEM STONES available in GOVT Stores which r very cheep, if u people don't mind i will be very happy and obliged if u people allow me to send some gifts to all 0f u. (i know u r 8 or 9 Moderators in this site.) PLEASE DON"T TAKE IT OTHERWISE i am a fatherly person. He shyam what feel to express i always express.thanks a lotsks

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

hi sks!1.my question was can we use general purpose ram instead of registers for temp counting and using registers for other purposes? yes u can use the spared region of ram (other than the available register banks.)this is how the RAM ia devided/configured:The 128/64 bytes of internal ram is subdivided as follows. The first 8 bytes (00h - 07h) are "register bank 0". By manipulating certain SFRs, a program may choose to use register banks 1, 2, or 3. These alternative register banks are located in internal RAM in addresses 08h through 1Fh.u have already used these banks in your code.Bit Memory also lives and is part of internal RAM. We'll talk more about bit memory very shortly, but for now just keep in mind that bit memory actually resides in internal RAM, from addresses 20h through 2Fh. The 80 bytes remaining of Internal RAM, from addresses 30h through 7Fh, may be used by user variables that need to be accessed frequently or at high-speed. This area is also utilized by the microcontroller as a storage area for the operating stack. This fact severely limits the 8051s stack since, as illustrated in the memory map, the area reserved for the stack is only 80 bytes--and usually it is less since this 80 bytes has to be shared between the stack and user variables. so u have 80 bytes of RAM left for use along with the register banks!But br careful or u might run short of RAM and then the uC might behave unexpectedly.in your case u might require only a few bytes and that will be OKthe data can be read by direct "Addressing mode" please go thru it in ur book!ex MOV A,30h This instruction will read the data out of Internal RAM address 30 (hexidecimal) and store it in the Accumulator. before further programming i wud suggest u to refer Ayala regarding memory organisation and addressing modes.we will discuss it if u feel any more problems..=================================================2. Now i will say i am going to use a NON VOLATILE MEMORY a EEPROM like 24c04/08 for storing the my preset data as well as last count data. my question was can we use general purpose ram instead of registers for temp counting and using registers for other purposes?these devices are I2C based devices..please download the philips I2C manual before starting the code. There are various protocols used in embedded systems .. one of them is this I2C.. other examples are UART (RS232) ,SPI,RS485,MODBUS,CANBUS ,IIS,SSP etc...==============================================3.ok pl let me know how i can attach/upload my CIRCUIT DIAGRAM or SCHEMATICS. first of all collect all data /files in a folder say sksData.compress it to either a rar or a zip.say sksData.zipthere are two methods to upload.1. use a file hosting web service like rapidshare.upload ur data there..u will get a link to it. copy the link say www.ra...link.rarcopy paste the link here.. and we can download it. to make it an active link while using the quick reply box.. select the complete link with you mouse and the n click the first button below which says Insert: link,,,,,or simply write """your link""" removing the double quotes.2. do not use the quick reply box use the post reply ( a green button below the quick reply box. select upload attachment and select yor zip file! easy!============================================= 4. One more thing u know ORISSA is popular for Handicrafts, filigree works and having a lot GEM STONES available in GOVT Stores which r very cheep, if u people don't mind i will be very happy and obliged if u people allow me to send some gifts to all 0f u. (i know u r 8 or 9 Moderators in this site.) PLEASE DON"T TAKE IT OTHERWISE i am a fatherly person. He shyam what feel to express i always express.sir jee main aapka padosi hun!! i am from chhattisgarh! we can accept it but only on these grounds...1.It shud not cost u much!2.we will make a "DEN" where all of us(all interested members,mods) can meet i was thinking abt mumbai. Your gifts will be kept and showcased there!if thats Ok with I will arrange things with Ajay and will do it soon!U are always welcome to express your feelings on this site .. we all have right to speech !! or let us say text

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello pdi,good morning. thanks for ur post. it was possible only because of all of u nice people. it was a dream for me for last 2 years which is achieved through you people only. u don't know i was moving around all of engineering collages in around bhubaneswar to find some body who can teach me. thanks all of you again for my achievement. ok i m trying to write a code for interfacing a 4*3 matrix keypad, which i will post within a day or two.thanks againsks

Re: need help to write code for 8051

pdi33 — 2009-01-08T08:57:15-08:00

sks wrote ... there was a query by pdi in previous post which is written below."another important aspect for object counting (if u r going to use it in a practical application in future) is the storage of the last count on power failure so that u can continue from the last count onwards. Please confirm whether that condition is required for ur application and i can suggest u a solution for it."Now i will say i am going to use a NON VOLATILE MEMORY a EEPROM like 24c04/08 for storing the my preset data as well as last count data. my question was can we use general purpose ram instead of registers for temp counting and using registers for other purposes? skshi sks,congratulations, ur first step towards achieving a preset counter has been completed ( at a very auspicious occasion i must say). That is a very good omen for better things to come. .Now, coming to ur query (most of them already explained by shyam), the last part is storing the set count and the last process count in the non volatile memory like eeprom, u have to understand first that eeprom has a limited write cycle life ( ideally about 100,000 times). So storing the set count there is o.k. as the event( storing data) comes quite rarely. But this is not the case in case of storing the process counts. Ideally, u will have to store the process count again and again for every count incremented. In this case, the write cycle life of ur eeprom used may not last very long.Still,there is one different solution for this problem but i think u should worry about it in the last stage of ur project. Till then, i would suggest u go slowly step by step and write the code for setting the 'set count' using some keys as input device and storing it in the eeprom.good luck.keep posting.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Shyam,good morning. "MUGAMBO KHUS HUA." thanks. i m extremely happy to know that u r from chhattisgarh. u hv described a lot of things in ur post, i will follow and let u know what i grasp from those things. it will take some time fr me. "we can accept it but only on these grounds...1.It shud not cost u much!2.we will make a "DEN" where all of us(all interested members,mods) can meet i was thinking abt mumbai. Your gifts will be kept and showcased there!if thats Ok with I will arrange things with Ajay and will do it soon!"My answer is...first of all why i shouldn't agree?it will not cost me much i assured you.i can send gifts through DTDC to mumbai if u tell me the address.if u r telling me to join with u at mumbai, there will be no problem, my younger son is working there, but it is only possible after DIWALI bcuz i hv some important job to finish. if u people r thinking to keep the gift in showcase at one place not taking individually pl let me know that so i can choose accordingly. thanks a lot to all of you.sks

Re: need help to write code for 8051

Arun Kumar V — 2009-01-08T08:57:15-08:00

Hello Sahuji, Congrats on your project's success ! u don't know i was moving around all of engineering collages in around bhubaneswar to find some body who can teach me i can say it is this determination that made you learn micros seriously. the tables are turned ,Now you can teach micros to Engineering students.but i feel you are hurrying a bit ( by moving on to key pad interface) , just now you have completed your counter project, so take some time to revise it or better try 2 or 3 versions or variations of the project. please don't "abandon" the project so soon. for example, when i did my count down timer project, i had 3 versions of it, same with the 7 seg - clock project. whenever i get time i recode my earlier project codes and add a bit of optimization.Arun

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Mr Arun;Thank you very very much for writing to me. my success is dedicated to you all, if i can write its due to all of your help."but i feel you are hurrying a bit". it is true. i will keep in mind ur advice. i hv also writen a 3 digit code using BCD to 7seg converter IC CD4511, i will post the same tomorrow to check and optimize by you people. as i don't have provision in my kit its not possible to check the code right now. i can assemble the display circuit on monday and inform. i m happy that pdi & shyam r guiding me. i know u r busy with ur project. i wish u a great success.thanks a lot all of yousks

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello Shyamgood morning to all. i hv uploaded my schematics in rapidshare. which is given bellow. i hv written a bcd counter code for the schematic. i m not satisfied with that main part. i want some other logical method for counting things. pl check and comment.thanks againsksCODE:;there are 3 cd4511 used in this counter
;abcd of all the ics are connected to p1.0 to p1.3
;latch enable pins are connected to p2.0 to p2.3
; a switch is connected at p3.0

org 0000h ;start from this location

mov r1,#00h ;load 00h in register1
mov r2,#00h ;load 00h in register2
mov r3,#00h ;load 00h in register3

main:
jb p3.0,main ;check for switch press

release:
jnb p3.0,release ;check for switch release

inc r1 ;add 1 with previous value
call display ;refresh display with new value
cjne r1,#0ah,main ;check if r1 <10 go to main
mov r1,#00h ;if r1 >= 10 load 0 in r1
call display ;refresh display with new value

inc r2
call display
cjne r2,#0ah,main
mov r2,#00h
call display

inc r3
cjne a,#0ah,main
mov r3,#00h
call display

sjmp main ;go back to main

DISPLAY:

mov p1,r1 ;laod r1 value at p1
clr p2.0 ;latch disable
call delay ;display for some time
setb p2.0 ;latch enable

mov p1,r2
clr p2.1
call delay
setb p2.1

mov p1,r3
clr p2.2
call delay
setb p2.2
ret ;return to caller

delay:
mov r6,#200 ;load 200d in register6

d1:
mov r7,#10 ;load 10d in register7

loop:
djnz r7,$ ;loop here and decrement r7 by 1 till r7 is zero
djnz r6,d1 ;loop between d1 and decrement r6 by 1 till r6 is zero
ret ;return to caller

end ;end of programhttp://rapidshare.com/files/153215015/3digit_bcda_counter.bmp.html

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hello pdigood morning . i hv uploaded a schematics in rapidshare. whose link is given bellow. i hv written a bcd counter code for the schematic. which i hv already posted. i m not satisfied with that main part. i want some other logical method for counting things. pl check and comment.thanks skshttp://rapidshare.com/files/153215015/3digit_bcda_counter.bmp.html

Re: need help to write code for 8051

shyam — 2009-01-08T08:57:15-08:00

Hi sks ,i am in a fix here on site.. with client over the shoulder almost all the time.. so cud now comment now...off topic:when posting a code c asm etc... use [ code = asm]code here[ / code ] remember to delete all the space like betweeen [ and code and code and = ... likewise or u can select the complete text with ur mouse and then press code:performatted.... button below just on the right side of [bq] button .try the same for links too..c u all later.

Re: need help to write code for 8051

sks — 2009-01-08T08:57:15-08:00

Hi Shyam,good morning. thanks for educating me. u must be seeing i am following ur advice, like writing comments etc. i will keep in mind what u hv said. i know ur advice, it is for better & methodical writing, am i correct? what about that gift chapter u people didn't answer..... plz......reply.thanks allsks