# Co-Processor pins are only ADC (analog input) or also usable as DAC (analog output)?

**URL:** <https://forums.balena.io/t/co-processor-pins-are-only-adc-analog-input-or-also-usable-as-dac-analog-output/59447>\
**Category:** balenaFin\
**Created:** [January 26, 2020, 12:57pm UTC](https://forums.balena.io/t/co-processor-pins-are-only-adc-analog-input-or-also-usable-as-dac-analog-output/59447 "2020-01-26T12:57:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Titanium](https://avatars.discourse-cdn.com/v4/letter/t/58f4c7/32.png) [@Titanium](https://forums.balena.io/u/Titanium)\
**Post date:** [January 26, 2020, 12:57pm UTC](https://forums.balena.io/t/co-processor-pins-are-only-adc-analog-input-or-also-usable-as-dac-analog-output/59447/1 "2020-01-26T12:57:21Z")

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Hi,  
the co-processor connector features 8x GPIO/ADC pins.  
Can those pins also used as DAC, meaning as a analog output? If yes, 3.3V or 5V?

Background, we are using currently the PWM pins of the RPI. I would like to get those free (one occupied pin is required for I2S/audio output).

Thanks  
Chris

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**Author:** ![srlowe](https://sea2.discourse-cdn.com/balena/user_avatar/forums.balena.io/srlowe/32/2638_2.png) [@srlowe](https://forums.balena.io/u/srlowe)\
**Post date:** [January 27, 2020, 11:48am UTC](https://forums.balena.io/t/co-processor-pins-are-only-adc-analog-input-or-also-usable-as-dac-analog-output/59447/3 "2020-01-27T11:48:58Z")

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Hello Chris,  
DAC is supported on the co-processor connector, however it’s IDAC, i.e. converts to a constant current (range 0.05 μA and 64 μA) rather than a voltage, so may not be suitable for your needs (at least without changes). Here’s the datascheet: [https://www.silabs.com/documents/public/data-sheets/BGM111\_datasheet.pdf#unique\_2](https://www.silabs.com/documents/public/data-sheets/BGM111_datasheet.pdf#unique_2)  
Regards,  
Scott