How to interface LEDs with a pot using 16F877 A/D converter?

[xjackal]

a/d c 877 help with asm

hi guys,
i need to interface a pair of leds(exactly 8) of them with a pot(linear) probabaly using 16f877 a/d cconverter.any help would be apppreciated.
:the problem is that i cannot see the leds starting from rb0 to rb7 but in random order.
and can u explain how the process works.

 

[cyr]

Re: a/d c 877 help with asm

Based on the little information you give, I'm guessing you make A/D readings and output them om PORTB?

In that case you get binary numbers represented on the LEDs, which might look a bit random if you don't know what your looking at.

Did you want some kind of bar graph or what?

 

[xjackal]

Re: a/d c 877 help with asm

yea,
thanks for ur reply.
its just what i need to do.starting from rb0 to rb7.like bargraph...
but how to do it..
many thanks

 

[cyr]

Re: a/d c 877 help with asm

This is untested code, but I think it might work.

I'm assuming you have the AD result in a memory location called "res" and have another location named "tmp".

swapf res,w
andlw 0x0f
movwf res
rrf res,f ; res is now divided by 32, so is in the range 0-7
incf res,f

clrf tmp

loop:
bsf STATUS,C
rlf tmp,f
decfsz res
goto loop

movf tmp,w
movwf PORTB

 

[xjackal]

Re: a/d c 877 help with asm

how about using a bargarph.how to use it.
because i cannot seemto work my codes properly.

 

[glenjoy]

a/d c 877 help with asm

Hi,

First of all, configure your ADC into an 8bit or 10bit ADC.

Second, in using an 8 position bar graph, you must divide your maximum level readout equivalent by 8.

 

[extradeath]

Re: a/d c 877 help with asm

Here is a good tutotrial about that

 

[extradeath]

a/d c 877 help with asm

I hope it is useful
please comment....