Hi there. Feather 32u4 question. Can I power a 32u4 from an existing 32u4?
There should be no problem with that - if you’re powering the first feather from USB, connect the USB pads together, and connect the GND pads together.
Therefore the secondary question. If I attach a li po battery to the 1st feather which will charge via the usb input would it then run both feather units if the usb power was disconnected? I understand these may be weird questions however I want to know before I proceed with my current build. If the answer is no then would I be able to swap the usb input to a li po batt and then run both?
The Adafruit 32u4 Bluefruit Feather has an onboard regulator that outputs up to 400mA. You’ll need to design around that limitation (which is rather generous). If you are working within that scope, then you could power other devices (another Feather or otherwise) by soldering to the 3V3 and GND pins of the first Feather.
When the Feather USB power is powered on, it will automatically switch over to USB for power. So you should be safe for most operations, but I’d still approach the whole process with a degree of caution.
I’ve slightly changed the plan with powering the devices. I’ve got a 1000mah li po battery that I will use to power 1 of the 2 boards I’m using. I think I’ll be able to power the 2nd board from the first that has the batt connected. Can someone confirm that I understand this correctly?
Also the battery can be charged from the USB. Is it also charged when connected to the micro usb or only when the USB cable is connected?
I thought that was your plan anyway. I’m not sure I understand your question sorry. The battery is charged when the device you’ve connected it to is being powered via the microUSB connector. I’d say that the best way for you to get an idea of how to power these would just be to sit down with them and get some hands-on time experimenting with the various options. Just make sure you correctly match your voltages.
More questions re powering. If I charge the lipo batt via usb, then disconnect the usb and power via the batt alone, does the board shut down so to speak once I stop using it? Or do I have to disconnect the battery in periods of in activity? Or do I have to un pair the device to shut it down when not in use?
Hope this makes sense.
Might be easier to just give it a go?