Need help on ADC : Software R/C filter

[luminas]

Instead of hardware R/C filer to delay ACD input, is it possible to do it with PBP ?

[Ioannis]

Depends on what you need.

FFT, Sorting and Average, DSP are some ideas.

What is your application?

What is your PIC?

What is your data to filter?

Maybe also your current program?

Ioannis

[luminas]

Hi Ioannis,
My application is simple, it just read the potentiometer / analog pins and then output the pulse accordingly.
Usually I put a hardware RC filter between the pots and the pins. It serves as delay





'PIC 12F683

OSCCON = $60 ' Internal oscillator frequency 4 Mhz


TRISIO = %00000011 ' Set TRIS to all input
ANSEL = %00000011 ' Analog channel RA0 & RA1
ADCON0= %00000000 ' VDD as VREF
CMCON0 = 7
DEFINE ADC_BITS 8 ' ADC resolution 8 bit
DEFINE ADC_CLOCK 1 ' Set clock source (rc = 1)
DEFINE ADC_SAMPLEUS 11 ' Sampling time 11ms

anpin0 CON 0 ' Analog port pin RA.0
anpin0val VAR byte ' Value digital 0 - 255


anpin1 CON 1 ' Analog port pin RA.1
anpin1val VAR byte ' Value digital 0- 255


PAUSE 1000

LOOP:

adcin anpin0,anpin0val
adcin anpin1,anpin1val

pulsout porta.4,anpin0val
pulsout porta.5,anpin1val


pause 10


goto loop

[HenrikOlsson]

Hi,
The great Tracey Allen has a couple of filter routines here (http://www.emesystems.com/BS2math5.htm). Make sure you read thry the explaination as it describes how to alter the timeconstant etc. Then there's Darrels averaging routine (http://www.pbpgroup.com/modules/wfsection/article.php?articleid=7) which might be interesting as well.

/Henrik.