I have the Particle Boron connected to the PR54-1 then to BMG-160 sensor. If I have the USB from the computer plugged in then power is transferred to the BMG-160 sensor. But when the usb is disconnected and the battery is plugged in there is no power to the sensor. I have tried bypassing the PR54-1 board and connecting to the BMG-160 directly and it worked on the battery. Not sure what else to try.
The Battery only provides 3.3V andI2C port needs 5V to power up the i2C devices.
for battery powered devices this module is recommneded
Ol I ordered the one you listed. Will see if that solves the problem