Stable ADC readings

[Acetronics2]

Hi,

What about reinitialising your Wsum value to 0 @ each 50 samples batch ??? don't you run this loop in another continuous loop ... ??? " par hasard " ...

BTW " PinProbe " is the alias for which pin ???

Alain

[dream-]

Hi,

What about reinitialise your Wsum value to 0 @ each 50 samples batch ??? don't you run this loop in another continuous loop ... ???

Alain

Oh I do. I left that part out of the code I pasted, but it is indeed running in an outside continuous loop.

PinProbe VAR PORTA.2
...
myLoop:

WSum = 0
Pause 100

For i = 0 to 49
ADCIn PinProbe, W0
Pause 10
WSum = WSum + W0
Next i

W0 = WSum / 50
...
LCDout $fe, 1 'Clear Screen
Lcdout $fe, $80
Lcdout "Reading: ", DEC W0

Goto myLoop

The readings I get with the ADCIN method are in the ballpark but move around too much. With the "manual" ADC method I get a stable value.

[Acetronics2]

ADCIN also polls for the ADCON0.1 bit ...

sooo .... aheum, how to tell it ...

Alain

[mister_e]

ADCIN also polls for the ADCON0.1 bit ...

sooo .... aheum, how to tell it ...

Alain

Yeah but we already say some odds with ADCIN in the past on some specific PIC, Microchip are good to change the way register are done, and how things work for PIC to PIC model...

This said, I never use ADCIN myself, but manually write/read ADC registers... it is also a bit less code hungry... down side "may" be when you port your code on another PIC who's not working the same way, or have different register name, bit assignment. big deal

[dream-]

Well if I understood what the problem was I would not be asking here

The fact is that the ADCIN code gives me an oscillating reading, and the manual method gives me a stable value.

I don't know the reason, but I would like to know. This is a 16F688.

[mackrackit]

For what it is worth I agree with Steve.
I tried ADCIN a couple of times and did not like it. Others swear by it though. ..

Keep doing it the way you are.

[mister_e]

I would love to see the whole code with ADCIN. Sometime if you play with some ADC registers, and you place them Before or After the DEFINEs, it may end-up with unexpected results.