Hey man, did you find a solution? Also can you give out more details about your robot? I am planning to do a similar thing but I am abit stuck and doing research.
The only viable solution, as posted by others is via Internet and using a mobile broadband connection. So this will have an impact of the "snapiness" of the controls, expect a slight delay in commands.
For the "remote" I was thinking of making an Android app you could run on a tablet. That app would have:
- some sort of D-pad buttons (since trying to emulate an analog stick might not have the best results).
- a slider control or something similar where you could set the speed of the motors.
- and in the center it would display the video feed from the Pi.
As a technical solution for getting internet to the Pi...well of course you are restricted to the carrier coverage of the area you want to use the Pi.
For the speed of the connection, I think we need a 4G connection for video streaming (I might be wrong, and would be happy if others can say otherwise). Here I kinda have narrowed it to three "solutions":
1. a 4G RaspberryPi HAT - https://www.aliexpress.com/item/4G-3G-2 ... autifyAB=0
- on the plus side it also has GPS module
- it's a HAT so minimal space usage on the project
- might have problems with documentation and linux drivers ???
- not sure how the HAT is communicating with the Pi for data transfer... USB?
2. a 4G USB dongle
- might have trouble with drivers and setting it up?
3. a 4G wirleless mobile hotspot
- it has the largest "footprint" so it might be hard to fit it in a smaller project
- if it has an internal battery...it;s another thing to manage. If you need to power it, you will need a PDB.
- but it has a big PLUS. It is the easiest way to connect it to the Pi via WiFi.
And...the final part, which I have not figured out yet... how do we set up the Pi to broadcast the video and "listen" for commands from a remote? Some sort of web server or service that should be permanently on on the Pi?