Raspberry Pi Zero + Phat Dac + Trinket


Hi I wanted to use the Raspberry Pi Zero with the pHAT DAC but also connect an Adafruit Trinket in order to control a neopixel ring (as per this article: http://learn.pimoroni.com/tutorial/raspberry-pi/raspberry-pi-programming-adafruit-trinket).

However, I can see that both the pHAT DAC and the Trinket use I2C to communicate. Will there be any issues using the same bus for these two components???

I don’t have an oscilloscope or logic analyser and would have no idea how to debug I2C stuff even if I did!


The pHAT DAC uses i2s, whereas the Trinket setup uses i2c.

You can see which pins it uses here: http://pinout.xyz/pinout/phat_dac

And these are the i2c pins: http://pinout.xyz/pinout/i2c ( the Trinket would use BCM 2 and BCM 3 )


Great, so there would be no issues?


Yup! Should be no problem at all. You can also chain multiple i2c compatible things off the i2c bus, as long as their addresses don’t conflict, if you ever want to add sensors or inputs into the mix.


That’s great, thanks! I assume you can set the address to ensure they don’t conflict?

Also do you know how much power the phat dac uses?


The pHAT DAC will use at most 17mA I believe.

Some i2c devices support changing the address, but not all. The Trinket, for example, sets its address in software so it can be changed easily to avoid conflict with other devices.