16F88 using comparators AND the adc

[Bruce]

You can setup one single ended comparator with RA1 & RA2, then use
RA0 or RA3 for A/D inputs.

@ DEVICE HS_OSC, CCPMX_ON, MCLR_OFF, LVP_OFF, WDT_OFF
    ' CCPMX_ON = PWM ON B.3, CCPMX_OFF = PWM ON B.0
    
    DEFINE OSC 20
    DEFINE HSER_BAUD 19200

    Comp    VAR BYTE
    AD        VAR WORD
    Symbol  COUT = CMCON.7  ' Comparator C2OUT bit

Init:
    ANSEL = %00001111    ' RA0 to RA3 A/D function
    ADCON0 = %10000001  ' Channel 0, A/D Frc osc, enable A/D module
    ADCON1 = %10000000  ' Right justify, Vref = AVdd/AVss
    TRISA = %00001111     ' All inputs
    CMCON = %00100101   ' Single ended comparator inputs on RA1/RA2 C2OUT inverted

Main:
    ADCON0.2 = 1        ' Start A/D conversion
    While ADCON0.2 = 1  ' Wait for A/D conversion to complete
    WEND
    AD = (ADRESH << 8) | ADRESL
    Comp = COUT
    HSEROUT ["A/D in = ",DEC AD,13,10,"Comp out = " , DEC Comp,13,10]
    PAUSE 1000
    GOTO Main
    END

For this example I fixed RA2 at 2.5V through a 1K voltage divider. RA1 is
the analog signal input to the comparator.

RA0 is configured as an A/D input. The analog input signal is wired to both
RA1 comparator & RA0 A/D input to display the analog value that flips C2OUT.

Used a 5K pot for the analog signal in.