I\p & o\p setting

TRISA0_bit = 1            '   input
  TRISC = 0x00              ' Set PORTc as output
  CMCON  = CMCON or 0x07    ' turn off comparators
  ADCON1 = ADCON1 or 0x00   ' Set AN0 channel pin as analog

AN0 channel (RA0) ' adc input
TRISC = 0x00 ' Set PORTc as output for relay , led & bzr
CMCON = CMCON or 0x07 ' turn off comparators
ADCON1 = ADCON1 or 0x00 ' Set only AN0 channel (RA0) pin as analog
porta.1 & porta.2 = Set PORTA as output for relay , led & bzr
porta.4 & porta.5 = Set PORTA as input for digital (means logic hi \ low)
ref volt is vdd (5v)

Click to expand...

REGISTER 7-3: ANSEL — ANALOG SELECT REGISTER (ADRESS: 91h) (PIC16F676 ONLY)
R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1
ANS7 ANS6 ANS5 ANS4 ANS3 ANS2 ANS1 ANS0
bit 7 bit 0
bit 7-0: ANS<7:0>: Analog Select between analog or digital function on pins AN<7:0>, respectively.
1 = Analog input. Pin is assigned as analog input.(1)
0 = Digital I/O. Pin is assigned to port or special function.
Note 1: Setting a pin to an analog input automatically disables the digital input circuitry,
weak pull-ups, and interrupt-on-change if available. The corresponding TRIS bit
must be set to Input mode in order to allow external control of the voltage on the pin.
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
- n = Value at POR ’1’ = Bit is set ’0’ = Bit is cleared x = Bit is unknown

Click to expand...