I have a zero running Volumio running with a phatDAC and Zero Stem soldered in. I am not intending to keep the pi running 24/7 so am looking for a solution to quickly, and most importantly safely, power on and off.
As the pi now gets its power from the usb stem, an On/Off shim is off the table. Is there a way to squeeze in a power button between the board and the DAC?
On/Off SHIM could still function as an off button. With no ability to cut the power from the Zero Stem, though, you’re never going to get proper On/Off functionality, because it’s not possible to shut it completely off. You could possibly use a USB extension cable and splice the power wire with a switch to solve this, but that may be a little convoluted. If you’re plugging directly into a USB port, though, you’re somewhat out of luck.
On/Off SHIM works by using a latching power circuit that a pin toggle from the Pi can latch into the OFF state and completely cut power to the Pi.