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query regarding seven segment display

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Moderators: Ajay, Junied , abbas1707, Arun Kumar V, pdi33, Shailesh NAYAK, ۞ TPS ۞, shyam, sashijoseph

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Arun Kumar V

Tue Jun 03 2008, 06:47PM

Registered Member #426

Joined: Sun Jan 28 2007, 11:50PM

Posts: 452
Thanked 190 times in 160 posts

Hello Priya,

i am sorry to say that this is one of the worst code i have seen so far, you ask why ?

1) what ever variables you have declared are not used anywhere in the program

2) what you want the code to perform is missing- objective is missing

3) you are simply loading some preset values into the display port

4) you are not comparing the ADC value to any known values

5) when you convert binary to Decimal you should first divide by 100D (64H) ,later by 10D
but you are dividing first by 10D and second also by 10D see here in your code 0ah i,e 10D:

CODE:

mov a,#33h

mov b,#0ah

div ab

mov r7,b

mov b,#0ah

div ab

mov r6,b

mov r5,a

6) and what are you doing with these registers : R7,R6,R5 ?

CODE:

seven segment_display: mov r1,#0

mov r2,#0c0

mov r1,#1

mov r2,#0f9

mov r1,#2

mov r2,#0a4

mov r1,#3

mov r2,#0b0

mov r1,#4

mov r2,#99

mov r1,#5

mov r2,#92

mov r1,#6

mov r2,#82

mov r1,#7

mov r2,#0f8

mov r1,#8

mov r2,#80

mov r1,#9

mov r2,#98

ret

7) what does this above Routine do ? - its rubbish

8) when a compiler compiles a code and outputs hex file, it doesn't mean that the code is error free - ever heard of "GIGO" term - "garbage In garbage Out"

9) provide a flowchart or block diagram of your logic so that we can help, forget " i have posted my logic in earlier posts" statement , nobody can track each and every thread in a forum,

Arun

This post has been thanked 1 time

priya123

priya123

Tue Jun 03 2008, 07:15PM

Registered Member #7113

Joined: Wed Apr 09 2008, 02:39AM

Posts: 48
Thanked 0 times in 0 posts

thanx a lot arun sir for tracking my mistakes,I am trying to build a data-acquisition system by using adc and microcontroller. i have already developed a look-uptable for the adc. providing a variable voltage at pin6 of adc i have found out the adc values by connecting all the datapins of adc toleds on my trainer kit.i am trying to programmy microcontroller in such a way that when i apply say,1 volts to adc the output should be 033h(according to the look-up table of ADC). i have connected pins of port1 of microcontroller to data pins of ADC. I want to see the display through seven-segment display ,so i have connected a seven-segment display(common anode type)to port p3 of microcontroller.

Arun Kumar V

Wed Jun 04 2008, 12:39PM

Registered Member #426

Joined: Sun Jan 28 2007, 11:50PM

Posts: 452
Thanked 190 times in 160 posts

Hello priya123,

here is my code in two versions : ver A - displays 3 digit decimal on Common Anode
Ver B - displays 2 digit hex value on Common Anode

verA :

: code deleted by Arun

and here is want you desperately wanted

Ver B :

: code deleted by Arun

Hope this solves your long time problem !

Arun

[ Edited Tue Jul 15 2008, 01:39AM ]

adc with seven segment display seven segment programing interfacing 7-seg display 7 segment display interfacing 7 segment display programming

This post has been thanked 2 times

nischay kumar , priya123

nischay kumar

Sat Jun 07 2008, 11:16AM

Registered Member #8311

Joined: Sat Jun 07 2008, 11:09AM

Posts: 31
Thanked 3 times in 3 posts

hello sir,

your program works perfectly, i have tried it and have learned new concepts in asm programming

nischay kumar

priya123

Tue Jun 10 2008, 04:59PM

Registered Member #7113

Joined: Wed Apr 09 2008, 02:39AM

Posts: 48
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thanx arun sir,your program code really helped me a lot,but still there is one doubt which i want to make it clear . i am using ADC(0804) in free-running mode. I have connected it to microcontroller(89s52) in the following way:
ADC(0804)
pin no:1 -------- CS grounded
pin no:2---------rd connected to port pin 2.5
pin no:3---------wr and pin no:5--------------intr shorted together
pin no: 3 ---------------wr connected to port pin 2.6 of microcontroller
pin no :5----------------intr connected to port pin 2.7 of microcontroller
pin no:6 ------------- variable input ,voltage is varied here
pin o:7--------------- grounded
pin no:8-------------------- grounded
pin no:9------------------- vref (1.28v) ,i have left it open
pin no:10------------------grounded
pin no:11 to pin no:18 (data pins) connected to pins of port1 of microcontroller
pin no: 19 -------------- connected to external clock
pin no:20--------------+5 volts vcc.
sir please tell me whether this connection is correct? if incorrect,then what corrections should I make?
please help.

Arun Kumar V

Tue Jun 10 2008, 07:25PM

Registered Member #426

Joined: Sun Jan 28 2007, 11:50PM

Posts: 452
Thanked 190 times in 160 posts

Hello priya123,

very late reply, about the ADC in free running mode , your current setup is not Free running mode-

in the free running mode, the ADC constantly converts the analog voltage at its input without the micro sending control pulses. one conversion triggers another conversion without micro's interference.

i have already described the connections of ADC in my above code:

;***************************************************************************
; ADC 0804 IS CONNECTED IN FREE RUNNING MODE
; VREF IS CONNECTED TO +5VOLTS
;
; GROUND PINS CS,RD,Vin-,DGND,AGND ON THE ADC
; CONNECT WR PIN TO INTR PIN ON THE ADC
;****************************************************************************

you only need to connect ADC's (D0-D7) Data bus pins to the micro's port, in your case its Port1.

when ever you want to read the input voltage , you just Mov contents of Port1 to Accumulator or any other Register.

interval between two readings should be atleast 1 uSec, which is not a problem when using normal 8051 @ 12 Mhz clock rate

Arun

priya123

Wed Jun 18 2008, 02:27AM

Registered Member #7113

Joined: Wed Apr 09 2008, 02:39AM

Posts: 48
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sir,please provide me the pin configuration of LM35 and LM34 sensors or sir,please give me any link from where I can get the pin configuration.

sashijoseph

Wed Jun 18 2008, 10:35AM

Registered Member #5870

Joined: Mon Feb 04 2008, 06:26PM

Posts: 554
Thanked 124 times in 117 posts

Look here : http://www.facstaff.bucknell.edu/mastascu/elessonshtml/Sensors/TempLM35.html

Google will give you umpteen links...do use it.

Let there be music........

priya123

Thu Jun 19 2008, 11:31PM

Registered Member #7113

Joined: Wed Apr 09 2008, 02:39AM

Posts: 48
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hello sir,
thanx for ur information on LM 35 sensors,could u provide me some more information about LM 34 sensor(fahrenheit sensor) ,its pin configuration and characteristics.

Arun Kumar V

Fri Jun 20 2008, 04:54AM

Registered Member #426

Joined: Sun Jan 28 2007, 11:50PM

Posts: 452
Thanked 190 times in 160 posts

hello priya 123,

use this forum for help when your preliminary search doesn't give you good results.

before posting your queries try googling, don't expect spoon feeding here. below are the results for what you asked