ADC not working - I'm a new member

[Heckler]

Here is another example of a small test program that will read the AN2 a/d converter and send it to a debug window.

one thing to remember is that the a/d converter names do not always match the pin #. example... AN2 does match PortA.2 but AN3 is actually on PortA.4.

If you have not used the debug feature of the PICkit programmer, you program the chip, power it up and then goto the Tools Menu and choose UART Tool. This will open up another Terminal window where you choose 2400 baud in the upper left and then click on Connect.

' 16F690
'****************************************************************
'*  Name    : UNTITLED.BAS                                      *
'*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2007 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 12/4/2007                                         *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
' 10-bit A/D conversion 
' Connect analog input to channel-2 (RA2)
' -----[ I/O Definitions ]-------------------------------------------------
 DEFINE DEBUG_REGG PORTA        'set debug port to porta
 DEFINE DEBUG_BIT 0             'use pin a0 of porta for debug
 DEFINE DEBUG_BAUD 2400         'set baud rate to 2400
 DEFINE DEBUG_MODE 0            'communicate in true mode
 
' Define ADCIN parameters
' Set number of bits in result
DEFINE  ADC_BITS        10 
' Set clock source (3=rc)
DEFINE  ADC_CLOCK       3   
' Set sampling time in microseconds
DEFINE  ADC_SAMPLEUS    50     
adcVar  VAR WORD ' Create variable to store result
' Set PORTA to all input
'TRISA = %11111111     
' Set up AD
ANSEL  = %00000100  'enable AN2, ALL THE REST DIGITAL
ANSELH = %00000000  'AN8-11 DIGITAL
ADCON0 = %10001000   ' RIGHT JUSTIFIED
ADCON1 = %00010000  'fOSC/8     
Pause 500               ' Wait .5 second
main:  
  ADCIN 2, adcVar ' Read channel 0
  ' do something with adVar here
  debug DEC adcvar,"  ",BIN adcVar,$0D,$0A
  Pause 100              ' Wait.01 second
GoTo main                   ' Do it forever

Good Luck

[johnbond]

Thanks Dwight - that will sort me out once I've got my Microchip PICKit 2 dongle to start working again. The fault with the dongle seems like it may be electronic, not software.

When I started this thread, I didn't have a MAX232 rigged up but I do now so from now on I can use the debug

Kind regards from Kwa Dukuza

John Bond

[mackrackit]

Check out the PBP manual under DEBUG.
Then look at
DEFINE DEBUG_MODE X 'X being 0 or 1 - TRUE or INVERTED

[johnbond]

Thanks for that "Heads-Up" Dave. I am scared of PC Com Ports after I got a 100V shock from one (half our 220V phase). I prefer using a MAX232 to a fried PCB. We tend to get Kong Fu PCs here and you never know what fascinating undocumented features are included. Maybe it's just Chinese revenge

Regards form the dark continent - Africa
John Bond

[johnbond]

OK Dwight, so you're a Gentleman! Thanks for that neat code. I works like clockwork

I now understand both ADC and DEBUG!

Regards from Kwa Dukuza on the dark continent of Africa
John Bond