Again ADC with 12F675 ...

[fratello]

Thank You so much for reply !
The rest of code is :

main:
pause 200
 ADCON0.1 = 1
 WHILE ADCON0.1 = 1 : WEND
 adval.HighByte = ADRESH
 adval.LowByte = ADRESL
 if k=0 and adval > 10 and adval < 750 then
 k=1
 pause 250
 endif

 while k=1
 gosub start
 wend
 goto main


start:

 ADCON0.1 = 1
 WHILE ADCON0.1 = 1 : WEND
 adval.HighByte = ADRESH
 adval.LowByte = ADRESL
if adval > 10  AND adval < 103 then gosub VolDn     

return

[HenrikOlsson]

Hi,

>The rest of code is :

Is it? You're calling VolDn but I don't see that in the code but I guess there's nothing to do with the ADC there?

Anyway, have you tried using ADCIN just to see if the message from ISIS goes away then?
I'm asking beacuse the DEFINE ADC_SAMPLUS 50 is for use with the ADCIN command I don't think it does anything for you when you run the ADC "manually". Alternativaly, whenever you're doing a converstion try:

ADCON0 = %10001001    ' Right justify, VRef=Vdd, select AN2, enable ADC.
PAUSEUS 100     
ADCON0.1 = 1          ' Start conversion
WHILE ADCON0.1 = 1 : WEND
adval.HighByte = ADRESH
adval.LowByte = ADRESL

In this case I don't think anything of it really matters since you're always sampling the same channel but it might be worth a try just to see if ISIS stops generating the message.

Finally, you're doing DEFINE ADC_CLOCK 3 but then you're overriding that by manually setting ANSEL to %00010100 which will set the ADC Clock to FOsc/8 instead of FRC. I don't think that's a problem in this case though.

/Henrik.

[fratello]

Thank you verry much !
Indeed, my mistake was the overriding of defines ...I didn't know until today the things You've posted. Hm ... so much to learn ! I'm glad I met people like You and other kindly members of this forum !
Best regards !

[fratello]

Me, again ...with something strange (at least for me) !
I try to use ADC for reading a couple of buttons. I have two situations :
- three buttons, with 82 ohms, 164 ohms, 1448 ohms resistors ; ADC reading = 1023 nothing pressed ; 78 with button 1 pressed ; 144 with button 2 ; 605 with button 3 ;
- three buttons, with 300 ohms, 1300 ohms, 3110 ohms AND 100 Kohms in parallel ; ADC reading = 1013 nothing pressed ; 236 with button 1 pressed; 575 with button 2 ; 768 with button 3.

I tried with 2 version of code (for both situations):

 ADCON0.1 = 1
 WHILE ADCON0.1 = 1 : WEND
 adval.HighByte = ADRESH
 adval.LowByte = ADRESL
if adval > 10  and adval < 300 then  gosub LED1
...etc....

and

ADCIN 3, adval
if adval > 10 and adval < 300 then gosub LED1
...etc...

For first situation everything works fine, with both version of reading ADC !
BUT ... for second situation, NOTHING HAPPENS !!! I really not understand what I do wrong ... Can me point to the right direction ? Thanks in advance !

[fratello]

Note : In Proteus both schematic work, so I made it on PCB. First variant works just fine, second none ...

[HenrikOlsson]

For the code using ADCIN, is the left/right justification set correctly? I can never remember which way around it wants it so whatever you have it set to, try changing it. And, do you have DEFINE ADCBITS 10 in there?

/Henrik.

[fratello]

Thanks for reply !

CMCON = 7
OPTION_REG  = %10000110
TRISIO      = %00001100	  		
GPIO        = %00000001
ANSEL       = %00010100   
ADCON0      = %10001001

I don't change anything in code (except values for actions) ... just the resistors from "chain" command.
With first chain work ; with second not. It's because of 100 kOhms ?!?

[flotulopex]

In your very first post, I couldn't find any clear description of your problem or goal....

Post#6
Attachment 7758 Attachment 7759

Post #22
Attachment 7766

Resistor coupling is apparently not the same in those two posts - is this okay?



Try this:

Button 1 = 0 Volt => ADC 8 bits = +/-0 , ADC 10 bits = +/-0
Button 2 = 1,25 Volts => ADC 8 bits = +/-64 , ADC 10 bits = +/-320
Button 3 = 2,5 Volts => ADC 8 bits = +/-128 , ADC 10 bits = +/-640
Button 4 = 3,75 Volts => ADC 8 bits = +/-192 , ADC 10 bits = +/-960

I didn't built the circuit above; if ADC values are not stable, try with all R values ( :10) => 10k becomes 1k, 3k3 becomes 300Ohms and so on.



As an alternative, you may want to have a look here "Compiled Tips ‘N Tricks Guide".

[fratello]

Thanks for info !