Hifi berry dig+ stacked on pi desktop card

Question

Hi - firstly, if I stuff this and blow up my boards, that is my responsibility, no matter what you tell me.

Now the only clash on GPIO pins is on GPIO pins 2 and 3, used by the hifiberry dig+ for I2S comms, and by the PI desktop for SDC etc.

1. Any experience of hat stacking these products?

2. General comments you can make about problems

3. Does the Pi desktop card do the HAT EEPROM check?

shabaz · Answer

Hi Simon,

There's too many unknowns, given both boards are proprietary. In principle it should work if GPIO2 and GPIO3 are being used for I2C, since I2C is designed for multiple devices to be attached. Whether it does work, and whether the drivers do anything unusual to lock out access to the I2C bus, I've no idea. You'd just have to try it I think. Risk of damage is low, but that's no guarantee.

I don't know about your last question, but it could be traced from the Pi desktop card if there is an EEPROM soldered to it. If there's an issue with having two HAT EEPROMs you could desolder the one off the hifiberry card and manually enable the device tree fragment for it - I don't know how to do that on the Pi but a google search will help find that explained elsewhere. If it doesn't work, an alternative is to use a USB sound card (they can be just as good or higher quality).