I'm beginning to think this power scheme just isn't feasible. In theory, the difference between theory and practice is small. So, in theory, it should all work, but that assumes the RPi is doing close to 100% efficient DC to DC conversion of 48V to 5V, and that the USB enclosure is doing 100% efficient conversion of 5V to 3.3V IIRC, the "standard" 1Gb PoE injector can do 16W at 48V (333mA) (although there are a bunch of PoE standards of varying power). Presumably, that includes a power budget for having at least one USB C port at 900mA. So, as long as the M.2 to USB enclosure is doing close to 100% efficient 5V to 3.3V conversion, the pi should just be able to power the modem. I looked at the EM7565 data sheet and it says max current is 1.3A at 3.3V (4.29W). This would be mounted in an enclosure on the antenna mast. The RPi can be powered by PoE, and the modem is powered over USB. I'm looking at using GoldenOrb on a RPI 4B and a Sierra Wireless EM7565 modem in a USB enclosure, but I'm wondering about power requirements.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |