I’m using Photons in an installation where someone turns on the power strip in the morning, and turns it off in the evening. Photons turn on, sync up to the WiFi, and everything is all good.
I wanted to add a few Electrons, just because I have them. In other projects, I always use the Electrons with USB power and a Lipo battery (a light on the board flickers without the battery, so I’m assuming it needs it).
I always remove the Electron’s battery when I turn the power off, but I won’t be there at the installation, and I can’t ask the person to remove the battery.
So is there a way to add an Electron to this kind of installation without removing the battery?
I’m asking this for this installation, but also for future ones, where I won’t have WiFi and will need cellular.
The quickly flickering LED just indicates that the LiPo charging circuit can’t find the battery (actually tries to charge, thinks the battery is full, stopps charging, rinse, repeat).
But this does not mean the battery is absolutely necessary as long your power supply is capable of providing the required peak current with the required responsiveness. So go for a PSU that’s capable to deliver at least 2A and also donate some extra buffering caps for speed.
This way you won’t have to have a battery connected.
There are some threads that also discuss how to mute that annoying flicker when there is no batter connected.
Additionally, AFAIK, there is a (not yet documented) command to open the FET which connects the device to the battery. But @rickkas7 can probably help you better with this particular one
That also answers another question we were discussing at my hackspace last night: does the Electron automatically charge the Lipo battery if it’s connected to USB power. Sounds like it does.
Yes, if you want to disable the battery and charging, which also disables the flickering red LED when you use a suitably large power supply, you can use this code: