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An 8051 Based Temperature Controlled Fan project

Sun, 19 Aug 2007 08:20:53 -0700

Can some1 teach me ho to do this hardware?what code should i write for this hardware?
This assignment as mention in the title,we need have the function as below:

-The system has 2 modes of operation: manual and automatic.
-In manual mode, a user may control the speed of the fan (either off, low or high speed) via push buttons.
-In automatic mode, the microcontroller controls the speed of the fan depending on the ambient temperature:
Off Temperature < 30ºC
Low speed30ºC Temperature < 40ºC
High speedTemperature 40ºC
-Regardless of the mode of operation, the ambient temperature is always shown on a dual-digit seven-segment display modules.ion
and what additional function can i add for this fan?I am very weak in doing this type of project...
Hope some1 can help me and thanks for helping

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 19 Aug 2007 13:55:14 -0700

hi cenadius,
welcome to rickey's world
talking about your assignment.. first of all.. decide which hardware to use.. i mean.. the temperature sensor, fan interfacing technique..

only after that.. writing a program for that hardware can be done. Also which language you want to use? C or Assembly?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 19 Aug 2007 17:54:12 -0700

Hi Ajay,thanks you first for trying to help me.
i only allowed to use assembly language to do this project and i will attach the part list to be use for you.Hope u can teach me how to do after see the electronic part that i will use in doing this project.Can i know what is fan interfacing tehniques means?sorry, i really very weak in this subject,so many term that i not understand.
1187571252_3470_FT1707_part_list__mlk_.pdf

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 19 Aug 2007 23:29:23 -0700

hey cenadius since u r using dc fan... so its a very easy task.what u have to do is analog to digital conversion and then pwm according to temperature from lm35.in c language its very simple task

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 20 Aug 2007 03:39:24 -0700

As said by abbas, the controlling DC fan can be done through a PWM on a pin. and reading LM35 is easy with the help of ADC. All you need to do is the calibration of temperature with the ADC o/p.
you can start building your schematic. Just try it once

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 20 Aug 2007 05:45:25 -0700

PWM is Pulse width modulation.. it helps you to control the output voltage by varying the width of a square wave pulse..

A Brief Description:

CODE:

|¯¯|__|¯¯|__|¯¯|__ ---> A square wave

|¯¯¯¯¯¯|______
<-Ton-><-Tof->.
<---Ttotal--->

Ttotal = ton+toff

Duty cycle d = Ton/Ttotal

if Vin is the input voltage and Vo is the o/p voltage.. then

Vo = d x Vin
where d is the duty cycle..
now if we vary the duty cycle we can control the o/p voltage
e.g. d = 0, then Vo = 0 -- o/p is zero
and if d = 1, then Vo = Vin -- o/p equals input
Now the value of d can never be greater than 1.
To control d, we need to control the Ton, if we reduce the value of Ton, then d decreases and hence Vo. similarly if Ton increases, d increases and hence Vo increases.

So d is directly proportional to Ton.
Vo is directly proportional to d
hence Vo is directly proportional to Ton

I hope you understood the concept of PWM.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 20 Aug 2007 05:14:02 -0700

Can i know what is PWM mean?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 21 Aug 2007 18:38:54 -0700

Thanks for ur explanation.This is the schematic that we need to use.Pls help me see got any problem?if i wan add other thing such as buzzer,how to add?Can u teach me how to write the code by using asembly langugae for this assignment?thx

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 22 Aug 2007 04:14:47 -0700

as the schematic is ready.. so you can start programming one by one.. which one you want to go first? write programs in small modules... and then combine them later on.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 23 Aug 2007 09:55:43 -0700

-The system has 2 modes of operation: manual and automatic.How to write the code for this function?teach me pls

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 23 Aug 2007 11:07:31 -0700

well this function can be implemented later on.. because this is the final interface. First you need to write drivers for your peripherals like ADC, keys, Fan and its speed control and 7-segment LED. After you finish the basic building blocks of your project.. you can easily make the final interface.. I hope you got my point. So you can first start with the simplest.. "Fan switching and speed control".
where is your schematic?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 24 Aug 2007 05:52:46 -0700

i maybe want add something to my circuit so i remove it first.So can u teach me how to write the code for control the fan speed in manual mode?i need write the code to control fan speed for manual and auto separately or just write 1 can d?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 24 Aug 2007 06:44:34 -0700

ok.. i tell you something.. controlling via manual or auto is the later part of your project it will be according to the keys user press.. that is the interface part. But basically you need to write for controlling and switching of FAN first.

And yes i will help you writing it..
So as i told you about PWM, you need a timer (either Timer 0 or Timer 1). and we need to load the timer for 2 different values, One for ON timer and one for OFF time (as explained for PWM square wave).
The value of ON, OFF depends on the mode selected by the user. i.e. If manual then you can have 5 preset values for user to select from and load them according to the selected value.
In automatic mode, i don't know how it suppose to work in auto mode..
So I hope you understood the basic idea.. can you make a simple code to generate a square wave? I will help you to modify it, according to your project waiting for your INPUT

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 05:37:55 -0700

sorry for taking so long time to reply u.Do u know what software that can use to draw the circuit schematic?This is the simple code u ask me to do which can get square wave,this program is use to generate 1hz square wave by using timer 1 with duty circle 50%,deration for high low portion of square wave are 0.5 s,T=1s.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 06:05:26 -0700

I think there is some problem with the attachment of file.. i need to check that..
By the time.. please try to paste the code..

here is a sample PWM code.. check it..

CODE:

org 0H
sjmp start
org 0BH
TIMER_0_INTERRUPT:
   JB F0, HIGH_DONE    ; If F0 is set then we just finished the high section of the
LOW_DONE:              ;   cycle so Jump to HIGH_DONE
   SETB F0             ; Make F0=1 to indicate start of high section
   SETB P1.0           ; Turn off LED
   MOV TH0, R7         ; Load high byte of timer with R7 (pulse width control value)
   CLR TF0             ; Clear the Timer 0 interrupt flag
   RETI                ; Return from Interrupt to where the program came from
HIGH_DONE:
   CLR F0              ; Make F0=0 to indicate start of low section
   CLR P1.0            ; Turn on LED
   MOV A, #0FFH         ; Move FFH (255) to A
   CLR C               ; Clear C (the carry bit) so it does not affect the subtraction
   SUBB A, R7          ; Subtract R7 from A. A = 255 - R7.
   MOV TH0, A          ; so the value loaded into TH0 + R7 = 255
   CLR TF0             ; Clear the Timer 0 interrupt flag
   RETI                ; Return from Interrupt to where the program came from 
start:
        MOV TMOD,#00H
        SETB TR0           ; turn on timer 0
        SETB EA            ; Enable Interrupts
        SETB ET0           ; Enable Timer 0 Interrupt
        MOV R7, #160      ; set pulse width control to dim
LOOP:
   SJMP LOOP          ;go to LOOP
   END

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 05:43:08 -0700

this is my code,why i cannot attch file?i wan attach the file that contain my code but cannot so i have to type it here

ORG 0000
MOV TMOD,#10H ;TIMER 1 IN MODE 1
MAIN: MOV R0,#10 ;COUNTER FOR 10 LOOPING
REPEAT: MOV TH1,#3CH ;MOVE 3CH INTO TH0
MOV TL1,#0B0H ;MOVE B0H INTO TL0
SETB TR1 ;START THE TIMER 1
LOOP: JNB TF1,LOOP ;WAIT FOR TIMER1 OVERFLOW
CLR TR1 ;STOP TIMER 1
CLR TF1 ;CLEAR TIMER 1 OVERFLOW FLAG
DJNZ R0,REPEAT ;IF R0 NOT ZERO GO TO REPEAT
CPL P1.0 ;COMPLEMENT P1.0 TO GET HIGH OR LOW
SJMP MAIN ;RELOAD TH1&TL1
END

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 06:04:20 -0700

ok.. but.. i wanted you to make it with timer.. for PWM, the delay should be less otherwise your motor will not run smooth.. you can try connecting an LED to the port to see that.. it will flicker a lot..
where as if you use keep delay smaller like timer in a 13-bit mode.. then you will see a variation in voltage instead of flickering..
I am attaching a sample PWM code for you.. take a look.

CODE:

MOV R7, #160   ; set pulse width control to dim

The above part of the code will determine the output voltage level. you can test this code.. by changing the value of R7.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 06:13:38 -0700

you can use orcad for making schematic.. but is not a free software... the schematic u showed me is made in protel. you can use the same software. or try some free software on internet like eagle.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 06:08:27 -0700

ok,thanks,but how u see the delay in my code?actually i found this code from book and modify it so i no very understand,and do u know what software that can use to draw the circuit schematic?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 06:54:49 -0700

Can u explain the function of this PWM code?why we need control output voltage level?The output voltage will affect which part of function of hardware?i not very understand,i am sorry that i only know ask question but i try to learn all this thing through doing this assignment,so i do it all by my own.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 08:39:00 -0700

PWM is to control o/p voltage.. to increase or decrease the speed of motor. as you said.. there is requirement of manual select for speed of fan.. so this code will be useful.
you can have preset 5 values, that you will load when user press a key
Please check your PM

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 30 Aug 2007 18:49:56 -0700

ooo,i see,but we just need 3 value which for fan run fast ,medium and slow and we only have 4 switch which use to set 3 value and change the fan between auto and manual mode.On the other hand,can u give me the link to download protel?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 01:45:19 -0700

i want add other electronic part to create extra feature for this program,cos this extra feature also cost us some mark,now i think i donw an add extra part d cos i donno how to connect iinto this circuit,and can u pls told me what should i do next after complete the pwm code?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 00:46:25 -0700

mmm... protel is also not free..
But the schematic you gave me is already a finished one.. so why you want to make another schematic?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 02:33:19 -0700

thanks,how to try on hardware?we need complete all the code only can insert into the 8051 microcontroller,right?then only can test,right?And how should i set all those value into the pwm code?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 02:21:05 -0700

Don't forget to test the code on the hardware.. and for three levels.. i think appropriate values can be..
Low: 30
Medium: 150
Fast: Switch ON the fan.. and stop the timer..

The next thing you can do is.. writing a code for 7-segment Display..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 02:44:31 -0700

i mean just try fan part.. check if PWM is working or not..
i mean to say... check if by putting the value.. are you getting a varying voltage or not.. that is what i meant with checking.
program once with first value and note the voltage o/p with a multimeter
then again program with second value and note the voltage.
then third.. and note the voltage..
In all three cases you should have a varying voltages. if that is coming then one module is ready.. then go to second part of your board.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 03:13:43 -0700

1)the code just now to set the ADC rite???what is the effect to 8051 and how that code function??
2)...i need to set 8051 to set for my fan to work rite?.what is the code that i need to make my 8051 get data from ADC??

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 03:14:34 -0700

Hariz.. please create your own topic.. or i get confuse answering you both.. this topic is for cenadius.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 10:11:24 -0700

AS shown in the schematic,if i wan set when i press sw2,the fan will run at low speed;when i press sw3,the fan will run at medium speed;when i press sw4 the fan will run on fas speed,so how i need to modified the sample code u give to to get the output like this?And can i do such that after i press sw2 then press sw3,it will automatic reset sw2?
1188580283_3470_FT1707_schematics_rev2.pdf

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 31 Aug 2007 11:40:59 -0700

well.. everything is possible and is not at all hard to do that i will explain how to do that ok!

all you have to do is.. wait for the key press.. and when a key is pressed.. execute some part of code related to that key.
So when sw2 is pressed it will execute the code for sw2, and set the fan speed, and if you pressed sw3 then it will execute the sw3 code and will set the new fan speed... overriding the old speed set by sw2.
Try to write a code.. to read which key is pressed.. and execute code for that key... PM me the code

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 03:59:56 -0700

I saw your code...
there are many mistakes.. i think you have no idea about what interrupts are.. anyways.. i explain you..
its like this..
whenever an interrupt occur, as clear from the name.. it interrupt the current processing of the CPU, and start executing the code which deal with that interrupt, that special part of code is called interrupt routine.
In AT89C51 there are 5 interrupts (2 external, 2 timer and one serial). and specific addresses are assigned to these interrupts in the ROM, which is called Interrupt vector location.
There is one more interrupt which is usually there in all the MCUs, called Reset interrupt and vector location is 00H
so whenever you press a reset button your CPU jumps and start executing from 00H.

This way for.. INT0 - location is 0003H
Timer 0 - 000BH
INT1 - 00013H
Timer 1 - 0001BH
Serial - 00023H

so whenever an interrupt occur it jumps to these location to execute the code.. and the code written in these location is called interrupt service routine. When you return from these routines you cannot use simple RET instruction. you need RETI (return from Interrupt).

In your code.. you are overwriting on location where timer interrupt has to jump. so you need to rearrange your code something like this..

CODE:

org 0H
sjmp reset

org 0BH
sjmp timer0int

reset:
--- your starting of program---

timer0int:
---the PWM code---

I hope you got my idea.. please try rearranging the code.. so i understand a better way what you did. if i feel anything wrong in the code i will correct it and send you back

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 05:32:11 -0700

what is the meaning of pullups?i compile the program,still got error,which is the reset there,from error columm it show say that symbol already defined,what is that mean?symbol defined also an error?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 06:38:42 -0700

its working properly no error!

CODE:

Build target 'Target 1'
assembling test.asm...
linking...
Program Size: data=8.0 xdata=0 code=85
creating hex file from "test"...
"test" - 0 Error(s), 0 Warning(s).

which compiler you using?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 06:16:40 -0700

mm.. i think lable is written twice..
i did not compile the program. and your program was having lot of errors..

Pullup means.. connect the pin to VCC via 10K resistor...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 12:22:08 -0700

well i don't know why it is giving you error.. can you please post the error? in detail?
or if possible download the demo version of Keil.. www.keil.com
because your code will be lesser than 2K limit of demo.. so you can use it...
if you don't want to do that.. then you need to give complete error details.
try to take a screenshot and upload it to www.imageshack.us and post the link here.. i will take a look at the error.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sat, 01 Sep 2007 09:24:38 -0700

i using Fet89c5x compiler

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 02 Sep 2007 03:52:58 -0700

Can u give the hint on how to start the 7segment program?The 7segment is needed to show the temperature value sense by sensor in the auto mode in celsius unit.The error link as shown below:
http://img505.imageshack.us/my.php?image=erorkn2.jpg

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 02 Sep 2007 04:19:33 -0700

hmm.. ok.. i think i first need to download your assembler and then check what is wrong..
regarding.. 7-segment.. search in the site.. you will get it in the forum..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 03 Sep 2007 06:03:23 -0700

just rename the label RESET with something else.. like main
and it will work.. test it. and tell me the results..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 03 Sep 2007 09:07:15 -0700

thanks,i test d,no problem

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 03 Sep 2007 09:14:14 -0700

so the fan working fine now? if yes then you can now start with 7-segment display

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 05:03:35 -0700

i hav read thru tis thread but i still got some problem to do with tis project. i hope to get some assist from u guys. thx

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 07:31:13 -0700

thanks for ur guideline,ajay,but 1 of my senior told me that we don need delay for 7segment code,cos it will alway display the temperature after get the data from adc

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 06:50:36 -0700

AJAY,I NEED MODIFIED MY PWM CODE WHICH WILL GIVE MY FAN 3 CONDITION FAN WILL OFF,SLOW AND FAST,CAN I CHANGE 1 OF THE VALUE INTO 0 IN ORFER MAKE IT OFF?SUCH AS SET MOV R7, #30 TO MOV R7, #0?ON THE OTHER HAND,THE SCHEMATIC CONNECTION HAD CHANGED,WILL IT AFFECT THE CODE SETTING?
1188913836_3470_FT1707_schematics_rev3_mlk.pdf

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 07:23:37 -0700

well its really simple.. where you set the value 30.. instead of that switch off the timer.. clear the TF0 and stop the fan.. clear the FAN bit. just like we did in fast mode.. do the opposite for stop

also i saw the changes in the circuit.. i also told you to connect pullups on switches like you did on transistors.

and for 7 segment.. you need not to write such a big code..
also there are lot of modifications that are to be done in 7-seg display..

i am going to explain you with example..
say... you want to display a number like 39 (in hex) on display..

so.. as you already got the decoded value for displaying numbers on 7-seg.. you just need to separate the number to display and send it to the port where they are connected

CODE:

mov dptr,#decodedtable ;load the decoded values
mov temp,a    ;where temp is a temp variable
anl a,#0F0H   ;we just need the higher nibble
swap a
movc a,@a+dptr ; load the decoded value for
                ; the number to display

mov 7segport,a  ;7segport is the port where 7segments
              ;are connected
acall delay       ;you need some delay here.. about 10ms
                  ;or more.. you can adjust it when u run
;then enable the common pin here
setb common1     ;for first 7-seg

;now we send the lower nibble
mov a,temp     ;restore the number form temp
anl a,#0FH      ;mask the higher nibble to extract
              ;lower nibble only
movc a,@a+dptr   ;load the decoded value for
                  ;lower nibble
mov 7segport,a   ;send the decoded value
setb common2    ;enable the common pin for
                 ;second 7-seg display
decodedtable:
db (decoded values here)....

The decode table will be the values you used in your program to send individual digits..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 07:33:02 -0700

hye ajay..i got some problem with my assignment which is about 8051 based temperature controlled fan.
i having some difficulty about the source code.so,can u help me ??

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 07:54:11 -0700

well cenadius.. we do need delay.. the reason is..
the 7-segs are connected to the same port.. and.. before the first 7-seg show the value you are deactivating it and displaying the second value... just test the code.. you will see nothing on 7-seg and you will see 88 on display.

the sequence is this way...
get the higher nibble..
move it to the seven segment port
activate the seven segment
put some delay
deactivate the seven segment
get the lower nibble
send to the seven segment port
activate the second seven segment
delay
deactivate it
This way you will see the proper value.
microcontroller execute instructions in microseconds.. so delay is must you can check with and without delay

@Natasha:
Please create a new thread.. and explain me your problem. I will surely help you out.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 08:11:30 -0700

what is nibble mean?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 04 Sep 2007 08:30:41 -0700

1 byte got 8 bits..
Bit 7 to Bit 4 - upper nibble
Bit 3 to Bit 0 - lower nibble..

combination of 4 bits is called a nibble

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 05 Sep 2007 01:44:22 -0700

can i ask u something here?
for the DPTR, it is 16-bit right?
then when we do this--> MOV DPTR,#decodetable
is it mean all decodetabe value also 16-bit?
or we jsut use the lower 8bits of DPTR?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 05 Sep 2007 05:18:10 -0700

ok.. here is your answer..
when we do mov dptr,#decodedtable
it actually load the address of the label...
lets say if your values are stored somewhere at 2000H then executing the above instruction will load the DPTR with 2000H. to fetch the values from that location we use instructions like..
movx - from external ram
movc - from code memory

as our decoded table resides in ROM/Code memory so we use
movc a,@a+dtpr --- a is loaded from the memory location pointed by (dtpr + a). and the loaded value will be 8-bit

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 05 Sep 2007 11:47:07 -0700

Ajay, can i write the code of this project without using interrupt?
but it will make the MCU busy as keep on checking the current state n do...
i have roughly write the flow of the whole program n realize that it maybe work, but not sure.
is it possible?
p/s: coz im really stuck at interrupt n dont know how to combine all parts...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 05 Sep 2007 12:32:49 -0700

well.. for PWM interrupt is must.. coz by the time u are checking and displaying the ADC value.. at the background your PWM will be running that is going to control the fan speed.

for ADC no need of interrupt!!

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 05 Sep 2007 19:37:58 -0700

how is the intterupt working when we still running other thing in the main function?
from the example in the book,
when we waiting for the intterupt, we just write a simple code like:
SJMP $
n it is simply waiting for intterupt occur, so how can i change it to keep on doing other in main?
is it simply continue n cancel the code " SJMP $ "?
p/s:the example in the book only teach waiting for the interrupt, n when that intterupt occur, the MCU will do the intterupt part n the main function doing nothing, so....confuse me...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 00:53:29 -0700

lol! you are funny.. i mean yes confusion can be there
ok.. is like this way...

sjmp $ means jump on the same location.. it is done this way.. when you do not have anything else to do in your program.. but in your program.. you have many thing.. which you need to do in a sequence and continuously.

CODE:

loop:
    check for key press
    read adc
    display adc
    sjmp loop

so doing the above work in loop will keep your controller busy.. and if in between the timer interrupt for PWM occurs, then CPU will save the data.. and jumps to Interrupt service routine execute that code.. and come back to the main program and do the work as usual in loop.

I think your problem is.. if CPU execute the ISR then what about the main code.. it get stuck or something.. so the answer is.. ISR will finish fast.. i mean.. wont take time for ISR to finish as only few instructions will be there in ISR and CPU execute them fast without wasting any time.. you will come to know when you do them in the program.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 06:25:20 -0700

can pm me the source code that had done ? i wan to try it ... thanks .... appreciate it very much .....

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 06:33:57 -0700

No Sorry! its his work.. i cannot send you

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 09:48:04 -0700

Ajay,how to write the delay code for 10ms?i write like this is it correct?DELAY:MOV R0,#10?what is subroutine code?is the subroutine code same as delay?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 10:54:37 -0700

here is the code for delay

CODE:

delay:
        mov r5,#50H
wait:
        mov R4,#255
        djnz r4,$
        djnz r5,wait
        ret

Routine is a part of code just like functions.. they are called routines or sub routines in Assembly. search in google for more information.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 11:23:48 -0700

how do i start the assembly code? which part to start? im noob here.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 12:31:16 -0700

please read all the previous discussions.. it will help you.. take help from your seniors too.. wherever needed..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 18:44:27 -0700

thanks,what is the diferent between R0,R4 and R5,how to knwo when i need use r0,r4 or r5,or other rvalue such as r2,r3?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 06 Sep 2007 22:01:26 -0700

those are registers... it depends on you.. how you want to use.. according to your requirement and ease of programming.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 07 Sep 2007 05:31:00 -0700

thanks .ajay,after 7segment code,what should i do next?write the code for adc?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 07 Sep 2007 05:39:08 -0700

ok,thanks,ajay can u help me check 7segment code on the other hand,can u explain to me the finction of the switch in the circuit?especially switch name sw-spdt,that switch 1 pin connect to ground and 1 pin no connected,it still an function?and is sw1 on off switch ?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 07 Sep 2007 05:35:17 -0700

ofcourse.. check the forum.. you will find the code...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 07 Sep 2007 06:08:13 -0700

well.. i think it would be better to ask Y.S Yong who actually designed the circuit because.. when you make a circuit you keep the functional working in mind.

and regarding 7-segment.. you need to check it on the circuit.. and please take help from your teachers...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 09 Sep 2007 09:45:08 -0700

compile it and then program the controller to see the results.. and check the output and compare the working as per your expected program.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 09 Sep 2007 02:43:26 -0700

Ajay, i finish writing program but not sure correct flow o not...
can u help me to check the program?
n how can i send the file to u?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 06:52:25 -0700

Ajay,
May I know how we can have preset values in PWM? How we can make PWM accept values from ADC after ADC have finished translating the analogue signal?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 08:38:00 -0700

after finishing the ADC conversion you will get some value from the ADC, as you want the fan to be at three speeds (OFF, Slow, Fast)
The values you used in case of manual can be used in auto mode too.. all you need to do is check the temperature.
e.g if temp is between less than 20° - Fan off (stop timer and clear the fan bit)
if temp is between 20° to 30° - Fan slow (run the PWM with the same value as decided in manual mode)
if temp is between 30° and above - Fan Fast (stop timer and set the fan bit)

This how the auto mode works.. and for PWM values you can use any value i suggest you using 100. Value can be between 0 to 255. as only slow mode is there so 100 is ok.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 09:32:04 -0700

So that's mean code for PWM that you've posted before is complete? We only need to write the code for checking condition, is it? What is the code to stop the timer?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 12:20:29 -0700

yes the code is complete..

tsubasa wrote ...

What is the code to stop the timer?

clr TR0 or whatever timer you are using.. the clear the timer run bit.. i cannot believe you people are really studying or what...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 12:55:09 -0700

Ajay, today i just try my program but.....so... :....7segment cant display properly...:mad:

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 12:45:51 -0700

Hehe. Relax Ajay. Cool.....down..... Actually the time I wrote that question was when I had been pressured by my group leader to finish the coding. I also don't know why I asked you that stupid question. Sorry for that.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 13:14:39 -0700

make a simple counter program to check..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 10 Sep 2007 19:30:19 -0700

Ajay,
for cenadius code he used 4 seven segment disp. What about if we only use 2 seven segment? The code is still the same, is it? The different only at the lookup table, right?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 11 Sep 2007 13:58:50 -0700

As per you said in PM...
you are doing wrong.. he said.. V is the ADC value.. from 0 to 255. LM35 gives voltage o/p in mV for every 1° rise there is increase in 10mV.
So if the temp is 20°C then the voltage o/p will be 20*10 = 200mV

Now when you work with ADC, the total voltage range is divided in 256 steps. so... each step is equal to 5/256 V
or 19mV approximately. So you might be having little error in reading the temperature but it will be very close to the actual one.

So.. all you have to do is.. convert the ADC value directly to the temperature value.. and make a lookup table for that.. as i said you can have V from 0 to 255 so, you will have 256 different values as answer, that will be your temperature

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 11 Sep 2007 22:21:57 -0700

i m really weak in assembly programming..May i ask some question which might sound silly to u all..?

when i wan to use a pin from my uC, i shud "SETB PX.X" right?

lets take a switch to pin P1.0as an example,

when the switch is on(do not grounded) den my P1.0 will detected as 1? when the the switch is grounded it will giv reading of 0. m i right?

e.g
a switch connect to P1.0
to control which mode to b used(auto or manual)
:wat i wan is when the switch is open den it will go to manual when it is grounded(pressed) it goes to auto

check out my code..

ORG 0000H
LOOP:SETB P1.0
JNB P1.0, AUTO
JMP MANUAL

AUTO:...................
..............
JMP LOOP

MANUAL:..............
.............
JMP LOOP

END

can tis stupid thing work? sry i m nt gd in programming. alwez ask stupid question..:P

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 02:11:27 -0700

as per your program.. it will surely work, only if the switch is a latched one.. i mean like the one you have in your circuit SPDT switch. the above code will work with that..
rest all parts depends on your code
and you wrote a good and correct code. so don't worry

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 03:59:59 -0700

Thx for the reply. wat about the micro-tact switch? the switch which will nt remain in the"pressed" position how shud i write the code? I mean how shud i detect it after it has been pressed.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 05:34:03 -0700

oic...actually i m using the same circuit as the rest of them... the micro-tact switches are used to control fan speed during the manual code...i was using code as below:

MANUAL: SETB P1.2
SETB P1.3
JNB P1.2,FAST
JNB P1.3,SLOW
CALL OFF

wher P1.2 & P1.3 are connected to the switches.
Then i realized it cant work.

FAST,SLOW, OFF are subroutines to control fan speed

thx for telling me it actually wont work..haiz.. i will try another code to detect the input from tis two switches.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 04:28:54 -0700

they are to be detected in the same way... but the thing is they wont be latched..
as per your program, you are reading a switch and then doing the work auto or manual according to the position of switch.. and after doing the work, you are again jumping back to read the switch again.. for micro-tact switches, the code wont work..
So all you can do is.. when you press the switch, clear or set a bit as per you want.. that bit can be as mode bit for your application..
So all you will do is.. read the mode bit, and see if its set then do auto if clear do manual..
and when the mode switch is pressed for changing the mode, just toggle the bit.. and mode will be changed automatically

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 06:06:46 -0700

If i use tis code, den i hav to add another switch?
i m wondering that must i "SETB Px.x" to use the particular pin? i do nt hav a correct idea wat must i write for the code to use hardware(the switch) to control the flow.
i juz learn it from some example codes,which they will use SETB Px.x before they start detecting the input from the pin.
Anyway thx alot for ur reply.. i hav asked lots of ppl (seniors, lecturers) they dun seem like wan to help ..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 05:49:18 -0700

well..
try the other way i tell you..

Manul:
JNB key1,off
JNB key2,slow
JNB key3,fast
sjmp manual

off:
;your code for fan off
JNB key1,$
sjmp manual

slow:
;your code for slow speed
JNB key2,$
sjmp manual

fast:
;your code for fast speed
JNB key3,$
sjmp manual

try this one.. is better.. it waits for user to release key and then go back for scanning agian..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 08:07:24 -0700

oo..so i need 3 pins/switches(key1,key2 and key3) to control the fan speed, m i right? coz i plan to use only 2 pins in the beginning , but since u tell me tis code is easier to b used den i will change it to 3 pins. thx again...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 11:06:06 -0700

Yes you have to use 3 keys...
and fourth for Auto/Manual.. it depends on you if you want it as the SPDT switch or micro-tact switch.. accordingly program will change..

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 12 Sep 2007 07:03:08 -0700

there is no need to do setb Px.x as by default on startup all the pins are i/p pins so no need to make then i/p again.
In the code i wrote above..
its goes this way..
in first three lines of code.. it wait for any key to press.. and waiting in the loop until a key is pressed. as soon as a key is pressed.. it jumps to the label specified..
after jump it execute that part of code.. and the statement
JNB keyx,$ will wait for user to release the key.
and as soon as user release the key.. it again wait for key press from the user...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 14 Sep 2007 13:31:23 -0700

what help you need? can you please create a new topic? this discussion is different from your requirement...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 14 Sep 2007 12:30:05 -0700

I need help regarding the report.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 17 Sep 2007 02:00:39 -0700

here is the complete code.. just read it.. see the instruction set carefully and try to imaging what is going on...
Test it on board directly.. and i cannot guarantee 100% working..
all you need to do is test it..

CODE:

;-------------------------------------------
;
;   Function of switches used in my program
;
;      SPDT = Auto/Manual
;      SW2 = Off
;      SW3 = Low
;      SW4 = Fast
;
;-------------------------------------------

automan equ P3.4
off     equ P1.4
flow    equ P1.5
ffast   equ P1.6
soc     equ P3.1
read    equ P3.0
fan     equ P3.3
mode    equ 20H
done    equ 21H
adc     equ 30H
adcport equ P2
MSB     equ P1.0
LSB     equ P1.1
seg7    equ P0

        org 0H
        sjmp start

        org 03H
        setb done
        reti

        org 0BH
        ljmp timer0_int

start:
        clr fan
        clr done
        clr mode
        clr MSB
        clr LSB
        mov IE,#10000011B
       
scan:
        acall read_adc
        JNB automan,auto
        clr mode
        sjmp manual
auto:
        setb mode
manual:
        JB mode,inauto
        JNB off,fanoff
        JNB flow,fanlow
        JNB ffast,fanfast
        sjmp scan

fanoff:
        clr TR0
        clr TF0
        clr fan
        JNB off,$
        sjmp scan

fanlow:
        mov r7,#50H
        setb TR0
        JNB flow,$
        sjmp scan

fanfast:
        clr TR0
        clr TF0
        setb fan
        JNB ffast,$
        sjmp scan

inauto:
        mov a,adc
        clr c
        cjne a,#30H,chk
chk:
        jc fanoff
        clr c
        cjne a,#60H,chk1
chk1:
        jc fanlow
        sjmp fanfast

read_adc:
        clr soc
        nop
        setb soc
        jnb done,$
        clr done
        clr read
        mov a,adcport
        setb read

        mov dptr,#ctable
        movc a,@a+dptr
        mov adc,a

        mov dptr,#dtable
        swap a
        anl a,#0FH
        movc a,@a+dptr
        mov seg7,a
        setb MSB
        acall delay
        clr MSB

        mov a,adc
        anl a,#0FH
        movc a,@a+dptr
        mov seg7,a
        setb LSB
        acall delay
        clr LSB
        ret

timer0_int:
   JB F0, HIGH_DONE
LOW_DONE:
   setb F0
   setb fan
   mov TH0, R7
   clr TF0
   reti

HIGH_DONE:
   clr F0
   clr fan
   mov A, #0FFH
   clr C
   subb A, R7
   mov TH0, A
   clr TF0
   reti

delay:
        mov r6,#20
wait:
        mov r5,#255
        djnz r5,$
        djnz r6,wait
        ret

ctable:
DB 0H, 0H, 1H, 1H, 2H, 2H, 2H, 3H
DB 3H, 4H, 4H, 4H, 5H, 5H, 5H, 6H
DB 6H, 7H, 7H, 7H, 8H, 8H, 9H, 9H
DB 9H, 10H, 10H, 11H, 11H, 11H, 12H, 12H
DB 13H, 13H, 13H, 14H, 14H, 15H, 15H, 15H
DB 16H, 16H, 16H, 17H, 17H, 18H, 18H, 18H
DB 19H, 19H, 20H, 20H, 20H, 21H, 21H, 22H
DB 22H, 22H, 23H, 23H, 24H, 24H, 24H, 25H
DB 25H, 25H, 26H, 26H, 27H, 27H, 27H, 28H
DB 28H, 29H, 29H, 29H, 30H, 30H, 31H, 31H
DB 31H, 32H, 32H, 33H, 33H, 33H, 34H, 34H
DB 35H, 35H, 35H, 36H, 36H, 36H, 37H, 37H
DB 38H, 38H, 38H, 39H, 39H, 40H, 40H, 40H
DB 41H, 41H, 42H, 42H, 42H, 43H, 43H, 44H
DB 44H, 44H, 45H, 45H, 45H, 46H, 46H, 47H
DB 47H, 47H, 48H, 48H, 49H, 49H, 49H, 50H
DB 50H, 51H, 51H, 51H, 52H, 52H, 53H, 53H
DB 53H, 54H, 54H, 55H, 55H, 55H, 56H, 56H
DB 56H, 57H, 57H, 58H, 58H, 58H, 59H, 59H
DB 60H, 60H, 60H, 61H, 61H, 62H, 62H, 62H
DB 63H, 63H, 64H, 64H, 64H, 65H, 65H, 65H
DB 66H, 66H, 67H, 67H, 67H, 68H, 68H, 69H
DB 69H, 69H, 70H, 70H, 71H, 71H, 71H, 72H
DB 72H, 73H, 73H, 73H, 74H, 74H, 75H, 75H
DB 75H, 76H, 76H, 76H, 77H, 77H, 78H, 78H
DB 78H, 79H, 79H, 80H, 80H, 80H, 81H, 81H
DB 82H, 82H, 82H, 83H, 83H, 84H, 84H, 84H
DB 85H, 85H, 85H, 86H, 86H, 87H, 87H, 87H
DB 88H, 88H, 89H, 89H, 89H, 90H, 90H, 91H
DB 91H, 91H, 92H, 92H, 93H, 93H, 93H, 94H
DB 94H, 95H, 95H, 95H, 96H, 96H, 96H, 97H
DB 97H, 98H, 98H, 98H, 99H, 99H, 00H, 00H

dtable:
DB 3FH, 06H, 5BH, 4FH, 66H, 6DH, 7DH, 07H, 7FH, 67H

END

Note: Temp 100° cannot be displayed on 2 7-segments.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 01:04:16 -0700

yeah!! At last my projects is ended,however it is a failure, but no matter what i wan post my highly appreciation here to AJAY who have give me so many help and guidelines in doing the coding part of this projects.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 02:29:58 -0700

actually my project failure is no bcause the code not working but the hardware got problem,it make my 8051 cant run,all my group mate even my senior also donno why, 1 of my lecture told e that my 7segment display got problem and have drag all the 8051 current and make it malfunction

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 02:02:35 -0700

I am sorry... for that failure.. but thats how you learn. it was a project work an assignment and if i would give you the code directly you could have never learn anything.
Now the working code is there in my last post so you can try it out
Thank you for your comments

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 02:57:48 -0700

hmm.. i saw your circuit and it doesn't look like you have problem with the 7-seg. Could be that during development process of the project it got malfunctioned. Still the real problem could only be found if i see the controller or the board myself.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 07:23:51 -0700

Sure i will update it...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Fri, 21 Sep 2007 04:55:07 -0700

Ajay, can u put the comment on the code to make me can understand how the code that u write flow? thanks

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 03 Oct 2007 16:11:23 -0700

hey,ajay,can u teach me how to write the delay code?my exam is near but i stil not understand on how to write the delay code,u just use any example u have and explain to me pls....

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 04 Oct 2007 05:52:22 -0700

can you start a new topic on this? i just don't want to confuse people...
There are common two methods to generate delay.. first is using timers and second is registers... so i will explain both of them and also answer your doubts. Please create another topic

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 04 Oct 2007 14:42:03 -0700

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 20 Jul 2008 23:09:53 -0700

Hi
I am also doing similar project
Here I want control the proportional valve by varying 0 to 24v(0-400mA) using 8051 PWM
Can you help me regarding the hardware?

Regards
chandu

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 21 Jul 2008 04:26:36 -0700

you can make use of L293D for this...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 01 Sep 2008 12:18:38 -0700

pdi i have single cycle 8051 the fastest one.. i think it can beat avr

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 21 Jul 2008 06:07:29 -0700

For PWM technique, it is very easy and compatible if u go head with PIC Controllers.
If u want more guidence, contact [BLOCKED BY ADMIN]

they are dealing with embedded projects based on 8051,PIC, AVR, ARM,Reneses and DSP processor also..U will get complete guidence on your academic and research projects.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 22 Jul 2008 06:42:45 -0700

hi nattu/chandu/naresh,
in the above project, the fan speed is controlled depending upon the temperature input but the temperature itself is not being controlled. so please confirm if u really want to control only the flow of gas for pr-determined levels of temperature OR whether ur valve is directly controlling the temperature because both the algorithms are completely different. If the former is true, then the above algorithm will hold good but if u require the latter one then better start a new thread with a detailed specification of ur requirements.do also mention whether u require a continuousl changing output(analog) or fixed predetermined output levels.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 22 Jul 2008 01:15:19 -0700

Thanks for reply

In the L293D have 4-channel driver, but for my application I need only one channel
It is the proportional valve which control the flow of the gas
The flow of the gas I have to control using micro controller PWM

Please can you send Hardware circuit related to this project?

Regards
chandu

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 31 Aug 2008 11:23:12 -0700

sure silver,
u can use any of the above ICs (AVRs) and if u have understood the concept well, u would find it very easy to write the code in AVR.
AVRs are much more faster/powerful than even the fastest 8051 processor available ( provided both run on the same frequency ).

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 31 Aug 2008 06:17:38 -0700

hi there, i am kinda impressed with this project, but i wish to ask, is there any other possible chips that i can use besides AT89S51? can i use maybe any other Atmel products like Atmega 8, Atmega8515 or Atmega 88?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 01 Sep 2008 20:04:25 -0700

i see, thanks for the quick reply. but i wish to ask a few more things. what is the closest AVR/8051 chip that can replace this AT89S51 for this project?

besides that, can the assembly code given by Ajay be applied in the other chips?

in the schematics given at page 3 of this project, can i ask is it possible that i replace the diode 1N4002 to 1N4003?

hope that you all can help me in this:P. thanks.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 01 Sep 2008 20:52:26 -0700

Ajay wrote ...

pdi i have single cycle 8051 the fastest one.. i think it can beat avr

i was expecting that comment .
i know of the single cycle 8051 core . i think the later versions of Amel 8051 derivatives all have it e.g. 89s2051. so i specifically mentioned the clock frequency because a single cycle core 8051 running @ 33MHz is indeed one of the fastest 8 bit uCs till date.;)

btw, no smileys menu for the reply box??

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 02 Sep 2008 12:55:38 -0700

well smilies are available at the bottom of reply box or there is smiley button now (I forgot to add image button).

I want you to take a look at this
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4078

33MIPS @ 33MHz

I am bit possessive when it comes to 8051 lol!

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 03 Sep 2008 07:47:13 -0700

very nice one. especially the two serial ports and 64k code memory part apart from the speed!!
i rest my case...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 03 Sep 2008 07:54:14 -0700

hehe.... lot of features are there... i simply love Dallas 450 controller

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 08 Sep 2008 09:11:27 -0700

hi there again, i wish to reconfirm a few things...based on the schematics on page 3 by cenadius which i assume is the final schematics...

i wish to replace the AT89S51 now with AT89S52, is it possible that it will work out as well?

besides that, i wonder if the final source code given by Ajay on page 11, is it working fine:P? or do i have to try it out myself? well cause i am trying to create somewhat the same circuit in this project for my graduation project, so just wanna reconfirm though:)

i hope the mods and admins can help me out in this:), i will be very grateful for your help, thanks.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 08 Sep 2008 09:20:55 -0700

sure silver,
the 89s52 has a larger code and data memory and is perfectly upper compatible with the 89s51.

As for the code part,do try it on the hardware and post any doubts/problems.c'mon man, atleast u can do that , can't u? ajay has provided u 90% of ur work and all u have to do is to try it out.!!

after all, the manufacturer has so generously invented the 1000 times re-programmable flash code memory in the 8051 so that u guys can experiment on ur coding skills. make good use of it!!

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Mon, 08 Sep 2008 22:42:21 -0700

This is the best microcontroller when comapared to other microcontrollers.
This is 16-bit microcontroller, Address lines. memory data.

###################3
vimal
widecircles

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Tue, 09 Sep 2008 09:01:55 -0700

@vimalnath,
are u talking about 89s52 or some other uC because 89s52 is a 8bit uC.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 10 Sep 2008 05:31:40 -0700

better u first study basic of micro controller
then by using diff hard ware interface them
then use simple complier like bascom-8051 to write program

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Wed, 10 Sep 2008 08:13:57 -0700

@vimalnath & rajesh,
please stick to the topic of the forum. do be clear on the matter posted so that other members can understand .
u guys can chat freely in the chat box provided as this is not the appropriate place.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 11 Sep 2008 10:41:57 -0700

ermm, can i ask one question about the circuit in page 3?

well its about the 7 segment display...i wish to ask are they common cathode or common anode?

besides that, what is the possible model name of the 7 segment dual digit display?

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Thu, 11 Sep 2008 11:08:45 -0700

@ silver,
they are common cathode. the model no. for a multiplexed two digit display depends upon the manufacturer. try browsing on the manufacturer site for the model nos.

P.S. the display interface part of the circuit does not seem to have adequate current protection. So pease add suitable buffer/current limiting resistors to the circuit for safety of the uC.
good luck.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 14 Sep 2008 01:37:22 -0700

ermm, i tried to connect and did all programming correctly.

unfortunately it did not work, i feel its really weird. my 7 segment well its trying to produce some number but its just all blur, meaning not giving any fixed value but shows some blinking.

besides that, there is another thing, the switches are not working as well, please help me out. thanks.

is it the programming that is wrong or the circuit?

oh wait, i did not see the page 5 has a circuit as well, let me try that out first...sorry for inconvenience

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 14 Sep 2008 08:13:51 -0700

i finally got the project working, fan working out well, OFF, LOW, FAST switch was fine.

the display of temperature is fine too but, the biggest problem is...the value does not stick at one value at one time, example the temperature now is 27 but it seems to be always blinking the value and when it changes to 26, it blinks as well and change to 26.

mostly if i were to see a proper 7 segment, it stays at 27 then when the temperature drops , it drops as well and does not blink repeatedly.

i hope you all can tell me how to overcome this problem:)...cause my friend tried to solve it last time failed as well. thanks.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 14 Sep 2008 06:32:57 -0700

Hi guys, I have a project with LM35 (with ADC) and a fan. how can I control the fan (on/off) with respect to the temperature ?

I mean how to perform these instructions in assembly language ?
Output of ADC is at P2 and stored in A

OFF fan if Temp < 31 Celsius
ON fan if Temp > 31 Celsius

Thanks for your consideration.

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 14 Sep 2008 09:29:09 -0700

silver,
the problem may be occurring because the code is executing some other part of the code which takes a bit of time and during the interval the whole display is blank. U can avoid blinking by introducing the scanning of the display in a timer interrupt service routine meant to execute for every 1msecond. If u have written the code in c-language, that would not be very difficult. but if written in assemble , take care to save the different variables before executing the display routine.
post ur code and we can try to find a way out...

Re: An 8051 Based Temperature Controlled Fan project

contact@nospam.com (Ajay Bhargav) — Sun, 14 Sep 2008 12:59:00 -0700

oh about the code, i am currently using the code on page 10 given by Ajay.

well i wonder if you can help me to look through it and see is there any way i can change the blinking of the 7 segment. thanks for looking through this, pdi33.

well of course its in assembly code form but i am pretty poor in my assembly code, therefore i wonder if you can help me out:)