Hi, I have a TinyZero circuit built, which runs fine off USB but won't seem to run off battery power.
The battery charges (amber light), but when the USB is removed the system doesn't seem to turn on. It's the 3.7V 150mA Li-Ion battery from TinyCircuits.
The circuit is: TinyZero hooked up to micro SD shield and to protoboard leading to an IR sensor pair, which logs beam-breaks. It works as expected under USB, incrementing the file name on startup (ie every time it's turned on with the power switch on the TinyZero, or the USB is re-plugged in, it starts a new data log on the SD.) But on removing the USB and trying to run off battery power alone, it doesn't turn on and doesn't write any files.
Not sure how to troubleshoot this.... am new to TinyDuino. Thanks in advance for any help!