Our scouting system runs on a web server. We run it on a battery powered Raspberry Pi in the stands and connect Android tablets to it via USB Ethernet dongles.
I’d like a way to get 4G or 5G network access into that system when possible. Does anybody know of a way to tether a mobile device to a router so that all our tablets can use the network when connected via USB Ethernet? I’m thinking one of the following should be possible:
Buy a router/modem that takes a SIM card and has an Ethernet port.
Buy a router/modem that has a USB port of phone tethering and an Ethernet port.
Figure out how to USB tether to a Raspberry Pi and have it share the connection via its Ethernet
Pretty much everything I’m finding online involves Wi-Fi which isn’t going to be acceptable for FRC scouting.
We’ve USB tethered iPhones and MiFi-style hotspots to laptops in the past with no trouble–you can turn off the Wi-Fi on a hotspot. (Reminder: you can get an old but capable iPhone for under $50 on eBay.)
A few of us swear by the GL.iNet routers, which will allow you to configure traffic to go over USB tethering while using an Ethernet port if you don’t want to deal with it on the Pi itself. The higher-end models have better features for when you’re at home, but performance should be pretty comparable in the stands with Wi-Fi off. They’re super versatile too–the one I bought for my old business went from being a way to keep 10 tablets online on a separate network with a captive portal to a Wi-Fi AP for my now-wife during COVID. Great Swiss-army knife.
I’d seen the GL.iNet on Amazon, but I wasn’t sure they would work (like could disable WiFi on them). Do any of them run on 5V USB power just like our Pi does? To get them tethered, you plug your phone into its USB port and set up USB tethering on your phone?
I Imagine you should be able to USB tether a phone hotspot to a laptop on the network, then on the laptop either share the internet from the hotspot interface to the LAN or bridge the two networks
My laptop battery only lasts a couple hours so that isn’t going to be a great solution in the stands for a 10 hours.
I bought a $30 GL-Inet router like Billfred suggested and confirmed that tethering to it works fine. The one I bought takes power over micro-USB, so it connects into battery very nicely. It will be our DHCP server and gateway, so I can reconfigure our Raspberry Pi and remove that functionality from it.
The new router can accept a 4G USB modem, and I’m trying to decide which one i could get that would be compatible. Google Fi can send me a SIM card to put in it for which I would only have to pay for data.
We use Laptops instead of tablets. That may allow for a faster connection. However, people using hotspots ruin all comms or at least make them have difficulty. I personally would go through with the second option. Or the third. I am however leaning closer to the second as it will save you time in the long run