Pi 4, Hifiberry, and touchscreen power

Question

I recently finished my basement and am in the process of getting it all configured, and one thing I wanted was to build a Raspberry Pi streaming device. I got a 3D printer for Christmas and found this case on Thingiverse:

https://www.thingiverse.com/thing:2921656

I figured it would be a fun project. I got a Pi 4, Hifiberry DAC+, and the official 7" touchscreen. When putting it all together in the printed case, I can't find any sort of instructions on how to power it all, at least from a single power supply. Powering the touchscreen with the Pi uses the GPIO pins, which is what the Hifiberry DAC+ connects with. I see it does have pins labeled 5V, but no GND pins.

https://www.hifiberry.com/docs/archive/datasheet-dac-pro/

Is it possible for me to power it all from the single power supply into the Pi, or will I have to do something else? The case seems to use a single connection, but I'm not sure what pins would be connected since there's no GND. (I did ask the creator of the case how they did it but no response yet).

I was thinking about cutting into the case to allow the touchscreen to be powered separately, but would rather not if there's a simpler way. I'm very new to soldering, so that's also a potential option if there are clear instructions and it's simple enough.

Answer 1

I figured it out. Solution for any future people:

I connected the GND pin on the touchscreen to the - 5V pin on the Hifiberry DAC, and then the 5V pin on the touchscreen to the 5V + pin on the DAC.

After that they would all power up with the official Raspberry Pi 4 power supply connected just to the Pi.

However, I couldn't get audio from the DAC even though the Pi recognized it and audio would come from the headphone jack. I thought it wasn't enough power at first. Lots of reboots and testing various scenarios. I then updated the Linux kernel on my Pi. Restarted and it worked! Using Volumio, but I'm sure it would work with Moode or whatever else you prefer.