I have a few Sinovoip BPI-R4s with PoE modules that all work. They also all have the Sinovoip WiFi 7 cards. I plan to power them all via both the DC barrel plug and the PoE port. The PSE that supplies power to all of the R4s will be connected to a UPS.
In a power outage, I’d like to be able to detect when power is coming only from PoE, so I can save energy* by disabling the 5GHz and 6GHz radios.
Does anyone have any idea how a BPI-R4 could detect if specific power sources are connected?
I think you'd better use UPS instead???
When your router is on high loading (which consumes more power), and suddenly the DC source drops, your router switches to POE (assume it's lower voltage), before the WiFi disabling your board is already not enough power which causes problem.
And indeed one of my R4s will be on a UPS, but I can’t afford to buy a UPS for every R4. PoE is higher voltage anyway at > 44V.
Edit: I’ve done some testing, and PoE alone is enough to run the WiFi card reliably in my use-case, but I want to conserve energy. I know I said I want to conserve “power” before, but I really meant energy. The PSE has plenty of power, but the UPS only has so much energy.
Why not monitoring the UPS (has it a status-interface?) - and when it kicks in manually send commands to your BPI-R4s to go into “low power mode”. Alternatively you can also monitor your mains power and if it goes down, send the command…
That's probably what I'll end up doing, but I don't have a plethora of devices that can monitor the UPS. The R4 that's colocated with the UPS is already using its only USB port for a Thread/BLE radio. At the moment, my only option is to ping a device that's not on the UPS or PoE. I'm not thrilled about that because every device that's not on the UPS or PoE gets planned down time occasionally.
Either adding USB hub to solve the problem, or just connecting UPS USB control to another device that can send NUTS, you don't need to make the problem over complicated.