Cellular Data Connection
If we can use cellular data to connect to the airplane then it could go really far and we could stay connected.
So far we are just looking at how to do it but will probably do this at some point. The first thing is a USB to 4G adapter like:
Next a very tiny Raspberry Pi Zero W:
Then it seems ArduPilot is needed. It runs on the flight controller but talks with the Raspberry Pi as a companion computer. The 4G modem plugs into the Raspberry Pi.
Peter has setup a 4gUAV gitlab repository that is really the place to go.
Here is a video where Peter flies a plane just from over cellular.
Also interesting is UAVPAL Disco4G. This uses a drone that can operate over wifi and puts a cell hotspot/wifi on it. This has latency issues for control. Over a cell network it is probably more reasonable to be sending GPS waypoints and not trying to directly fly (as this seems to be).
ArduPilot 4G Hardware
ArduPilot Raspberry Pi Flight Controllers
Videos with ArduPilot and Cell Data Years Ago
- 3G telemetry on ArduPilot 2.5 (APM) via a Raspberry PI (RPI) Apr 14, 2013
- 3G telemetry on ArduPilot 2.6 (APM) via a Raspberry PI (RPI) Sep 23, 2013
- Skywalker X8 with Arduplane AMP 2.5 / 3G/4G Cellular Telemetry and video using Raspberry PI (RPI) Sep 13, 2013
Not cellular data but kind of related.
There is Open HD which uses wifi frequency to talk to drones.
The open source ExpressLRS is a long distance open radio link. Works on iNav.
Software tools for 4G on plane
A key tool is Reverse SSH. Imagine the Base Station has a fixed IP. The airplane does not have a fixed IP. The airplane does a reverse ssh to the base station. This sets up a port on the base station that is forwarded to the airplane. So software on the base station can connect to software on the airplane. For more on Reverse SSH see here.
On Windows10 OpenSSH Client and OpenSSH Server are optional features. So it is not too hard to enable these. We need them so the plane can connect to ground control.
It would be nice if while we were cruising over empty ocean we had a low datarate video and then when we were getting near a boat or something interesting we could up the datarate. This could save us money on our 4G bill. This does not seem to be trivial, so we may not worry about how to do this till we get a few big bills. But if anyone knows a reasonable way, please comment.