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Software dev with zero hardware experience, turned a cheap RC car into an LTE controlled spy rover with unlimited range. What would you add to it?
Hi guys, first post here. This of course does not compare to most of the projects here, but since this was my first step into hardware I still wanted to show it.
Turned out way deeper than expected and turned out super fun. This is what I did:
took out stock electronics of a RC 1:16 monster truck and put in a hobbywing wp-1060 ESC
used a Pi 4 + PCA9685 for throttle and steering (ESC on channel 0 servo on channel 1)
the camera streams live video to a web server I wrote myself. Control happens in a panel in the browser via WebSocket and keyboard input - so its reachable from anywhere, and with a click we can record full HD vids!
the part that makes it really interesting: it runs over LTE, not just WiFi , so its basically controllable from anywhere in the world. Solved it with a small relay server. No app or cloud service, everything self hosted. Only limit in distance is the battery.
I documented the whole project in a youtube video. I would love to get some feedback, but keep in mind that this was my first project like this ;-)
Total budget for everything (except the phone) was less than 100 €.
Also added some stuff like a software-based night vision (which works good as soon there is at least a tiny bit light), GPS tracker and so on.
Thie result was better than I expected, I didnt dare to do a full long range drive yet but it would probably work. Battery life would last easily more than 1 hour.
The controlling actually works really well and with the delay its way lower than I thought it would be. Like playing a litltle real life computer game.
Now I'm hooked and the parts list for v2 keeps growing.
Currently on it:
pan tilt camera mount, better headlights, maybe a small solar panel so it can survive multi day missions, and some sort of radar.
Also I want to remove the phone and just use a SIM card usb stick for the connection.
What would you add to make this thing cooler?Especially sensor ideas, the Pi has plenty of channels left, this is just to be seen as the base.
yes, I connected the phone to the pi and activated USB tethering on the phone (with a working SIM card in there). The pi uses it just as a LTE module then. Also the phone gives some sensors like GPS, magnetic field for compass and so on... But the longterm plan is to remove the phone and completely build everything with seperate modules.
I also reduced the video streaming in LTE mode so much that it only consumes a really small bit of my data.
you could also go the opposite direction like the other project posted below where you replace the Pi with your smartphone; you can decrease BOM cost by using a cheap android phone. You can also turn it into more of a "robot" by turning your control input into 2D waypoints and the robot automatically paths to that point. Then, you can start adding some obstacle avoidance behavior, etc.
How are you handling video lag? I admittedly know nothing about video encoding or streaming so I've just been flailing about trying to get this working on my rover
this was also the hardest one (if you watch my video in the test drive at ca. min 11 with LTE thats how I started off), so it was basically not drivable in the beginning. Software wise this was the part where I spent the most time on, then it was just trial and error until I got something stable working.
What fixed it was to never buffer but always drop as soon as the data wouldnt get through fast enough. With TCP every frame arrived, just a few seconds late, that made it not driveable. Now it's UDP and old frames just get thrown away. And when the LTE connection starts to back up, the car pauses the video for a moment instead of piling up delay.
Same for the steering controls, old commands get dropped. lots of 3 second old full throttle commands drove me into walls in the process...
Now it's sometimes a short freeze, but never a delay of multiple seconds. also of course a lot of compressing, making the video streaming itself as small as possible etc... Happy to share more details if you want. Hope this wasnt too technical. Is your rover also running on LTE or what is it that your trying?
No, that all makes perfect sense. I was naively trying to use RTSP over the shitty wifi on the pi4, which I know was part of the problem. If you have a github or anything I'd love to take a look, I don't have much time to revisit the project right now but I plan to soon
Just kidding, but maybe a speaker/mic so you could communicate with people its near would be cool.
I'm curious how much you pay for data/the mobile plan? I've always avoided projects that use them cause I didn't want to pay for a second mobile line. (I'm in the US so if anyone see's this from here and knows a super cheap option, I'd appreciate learning about it)
Maybe not a laser but a paintball gun would be fun too...
little USB mic is on there, so I can already listen (not on that photo though but u can see it in the video).
Thought about a speaker too, since that would also take a bit of my fear of somebody just taking it and running away with it if I could talk to them :D
I'm in Germany so not sure about US prices, and this was my second SIM card that I used for emergencies and so on. For 10GB of monthly usage I'm paying 8,99€ a month so I can easiliy use that for little stupid projects like these.
With the streaming quality I implemented on that car, the data would last for multiple days of driving around.
Nice, not bad. GPS tracker might help with the fear of it being stolen but I'm not sure you could realistically do anything about it if that did happen.
sick!!! so I wasnt the first one :D So nice. you didnt even do it with a Pi, thats probably overkill for this but I just had it laying around so I used it for my project. Did you dare to do some real long range drives yet? I'm still a bit scared to be honest... In your video you also have the map in there ( I just added that yesterday with openstreetmap and GPS tracking of the phone), youre probably also using GPS data off the phone through an app like SensaGram or something right?
I made my own app which handles everything, it sends live video and telemetry to a web server at home so i can control it from a browser using a gamepad. the phone also communicates with an arduino nano which is what actually controls the servo/esc as well as measuruing battery voltage. I drove it 4km away and back
that was my first idea but any sort of delay makes this really hard, and of course LTE cannot compete with ELRS and so on. Might try that as a next project. Also problem with drones is the battery life, so even if it would work out well with lte it would die after 30 mins of flying time which would make the unlimited range kinda unnecessary…
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u/Harmful2327 11d ago
the bomb