On your Devlight/DevFull there are 3 signals to use the Max5821:
- DAC_OUTA: corresponds to OUTA (pin 7) on Max5821. It's the first output.
- DAC_OUTB: corresponds to OUTB (pin 8) on Max5821. It's the 2nd output.
- DAC_REF: corresponds to REF (pin 6) on Max5821. It's the reference voltage (max value that will be achieved by outputs). This input should be connected to a voltage reference between 0 and 3,3V.
The Max5821L DAC can be controlled from the user space by using the setDAC function. No special driver is needed except the i2c host one, which is statically built into the kernel.
To set the DAC outputs to a given value, use the setDAC command:
# setDAC ##Usage: setDAC OUTPUT [VALUE] power down or set DAC output with value 0 - 1023 OUTPUT is A , B or AB (both) VALUE must be 0 - 1023 If no VALUE is given, then the output is powered down ##