Owner's manual

AN130

8 AN130REV2

MOVLW 0xFF ; Load W for new delay count

CALL delay ; Delay for Oscillator start-up 158ms

;*** ADC Serial Port Initialization ***

MOVLW 0x0F ; Load W with a value of 15

MOVWF TEMP ; Loop count variable = TEMP

BCF PORTA, CS ; Clear CS to enable ADC

loop: MOVLW 0xFF ; Load W with all 1’s

CALL send_byte ; send all 1’s to ADC

DECFSZ TEMP, 1 ; loop through to send 15 bytes of all 1’s

goto loop

MOVLW 0xFE ; Load W with last byte - ’11111110’

CALL send_byte ; send final initialize byte to ADC

BSF PORTA, CS ; Set CS to disable ADC

RETURN ; Exit to "main"

;*****************************************************************************

;* Routine - calibrate

;* Input - none

;* Output - none

;* This subroutine tells the ADC to perform self-offset calibration on Setup 1

;*****************************************************************************

calibrate MOVLW 0x81 ; Command for Self-Offset Calibration

BCF PORTA, CS ; Enable ADC

CALL send_byte ; Send Calibration Command to ADC

poll_sdo1: BTFSC PORTA, SDO ; Wait until SDO falls to indicate

goto poll_sdo1 ; calibration completion.

BSF PORTA, CS ; Disable ADC

RETURN ; Exit to "main"

;*****************************************************************************

;* Routine - modify_gain