I just got an inquiry about the Waveshare USB cell modems and thought it would be good to forward my info here for everyone. I’ve recently circled back to the cell stuff and have not been happy… I have more work to do but some insights aren’t going to change I fear.
At this stage I cannot recommend any USB attached cellular radio, the reason being that the USB ports on rPi3 and rPi4 are limited to 1.2A total. This is insufficient for a couple of FCDs plus cellular and leads to over-current warnings in the logs and non-
functioning of the cell radio (and FCDs).
If you use a powered USB hub and attach the radio to it then it works, you can typ. power the hub from the Pi 50-pin connector. This is a way to make purchased USB radios work…
Right now I would place my bets on the HAT versions. Both the Waveshare and SixFab HATs should be fine. The SixFab ones come with different radio modules and I don’t quite know what to say. Josh at BofC has some that seem “less happy” but it’s really difficult to tell whether it’s radio module or SIM or signal that is the issue. The twilio super smart
SIMs (used by Sixfab’s service) are difficult to work with because when they don’t just work they iterate through various global “personalities” trying to find a carrier that works. I have not tested the Waveshare HAT, but that’s what I would get.
My main recommendation to anyone would be to get at most one or two devices and be ready to immediately test them so they can be sent back and before ordering a bunch. The SGv2 software should work with most any modem and I’m happy to assist. And you do not really need any special service to track devices, the cheapest SIM for a carrier that works at the location is fine. In the US there are some unlimited 64kbps SIMs that are quite cheap.
When testing, please do think about alternate internet access to your test devices. This allows log files to be uploaded to SGhub even when the cellular fails and that’s how I can assist. The best is to have an ethernet cable you can easily pull to ensure the cell stuff
works (use the hotspot to monitor). WiFi can also work similarly. If things don’t work and you’d like me to help the best it to ensure the SG has internet via wifi/ethernet within 24-48 hours for ~24 hours so it uploads logs.
Sadly cellular is still a nightmare overall in my experience. It can work great but if it doesn’t it’s so difficult to troubleshoot. I want to try out more devices but I also have a long to-do list already…
If anyone has experience with alternatives, please chime in!
