Troubles with I2C_Write

[Chris Barron]

Do you have appropriate pullup resistors on the I2C clock and data lines ?
I have seen values from 1.2k to 10k work to good effect. The lower the value the less susceptible the signals are to noise

[The Altruist]

Hm.... false alarm. The DAC chip was bad.
We have it (or at least a simple saw tooth wave demo) working now:

;@   __CONFIG    _HS_OSC & _WDT_OFF

DEFINE  OSC 20
DEFINE	I2C_SLOW		1




' Allocate RAM
result		VAR		WORD			' ADC result                            '2
Iter    	VAR		BYTE			' Generic Iterator						'1


' Initialize ports and directions
        TRISB.1 = 0				' Pin for SDA
        TRISB.4 = 0				' Pin for SCL
		

mainloop:						' Main program loop
		'This should set the DAC to output.
		FOR ITER =0 TO 254
		result = ITER
		result=result<<4
		PAUSE	100
		I2CWRITE PORTB.1, PORTB.4, $9C, [result.HIGHBYTE, result.LOWBYTE]
		NEXT
		FOR ITER =255 TO 1 STEP -1
		result = ITER
		result=result<<4
		PAUSE	100
		I2CWRITE PORTB.1, PORTB.4, $9C, [result.HIGHBYTE, result.LOWBYTE]
		NEXT
		goto mainloop