Hello, as the title states, I am looking to get started with an autonomous RC car. As someone who has been into RC cars for a while now and is a big fan of the rctestflight YouTube channel, I have wanted to get into autonomous RC cars for a while but am not sure where to start as far as hardware goes. I have plenty of chassis’ that I can use for the project and also plenty of basic ESC and motor combos to use. Most of the questions I have are Tx, Rx, and flight-controller based. From my understanding, you can’t really use the normal two or three channel steering wheel type transmitters for this. As far as what I have that may work, I recently got into planes and bought a Spektrum DX6 radio to use with them, but am still unsure of what flight-controller and receiver would work. If anyone has a similar setup using a spektrum aviation radio, or has experience with other hardware, I would appreciate any recommendations. Thanks.
I went that way several years ago. Randy kindly helped me finishing it.
Important notes:
- For first tests limit speed, just in case. I used a low maximum throttle pulse width, slightly over neutral.
- On new versions any channel can be used for mode change, not only 5.
- RTK important for a real circuit. Better “predict” a good day for tests, specially if there is GPS shadowing (on circuit shown the podium caused it to increase, as shown on graphs).
- For arming, disable magnetic interference (single motor). Observe in videos there that car can start and accomplish missions even starting 180º rotated.
See Pixhawk 1 on car shown, which fits on 1/10 car. For newer rovers I used Matek H743 Slim.
Any, but don’t expect real R/C racing car performance. Use a low performance combination.
Any, sticks or wheel, even with two channels (GCS for other than steering/throttle). From the beginning I wanted to use a car radio. A third channel would do mode change (knob in T3VCS shown), and with a four channels radio you could simplify arming/disarming.
Tests pending (perhaps some day…):
- DO_CHANGE_SPEED on straights.
- Object avoidance, or attach a rotating lidar and observe surroundings (yellow radar).
- Simultaneous RTK and live 4G or 5G transmission.
- Trajectories (splines…).
I’ve done a bit more reading up on what I’ll need and the different options people recommend and here’s kinda what I’m thinking of using.
For the chassis, I think i’m going to start with my Losi touring car as it is slow, has a regular 2s powered brushed esc and motor, and plenty of room inside for all the components.
For the rx and tx, I think I might order the Radiolink RC6GS transmitter and R7FG receiver combo as most of my cars run on traxxas radios or stock spektrum radios, and I would like to keep it on a wheel style tx. Also the R7FG has s-bus and ppm/pwm which from what I’ve read are necessary inputs for the flight controller that the traxxas receivers lack and would require a converter of some sort.
For the flight controller itself, i’ve seen people using the pixracer, but it seems a bit older and outdated. I’ve also seen recommendations for the Kakute F7 AIO and the pixhawk 4 mini but am not sure what advantages either has over the other.
Edit: I’m now looking at the SpeedyBee F405 wing as a flight controller option
For GPS i’ve seen a lot of different recommendations but it seems any of the holybro m series (like the m10 or m9n) are good.
Also something I forgot to include in my original post is my plans with this project. With the losi touring car, i sort of want to use it as a test bench and just do waypoint missions around parking lots or trails and maybe mess around with having it follow me around (I saw a forum post on this but haven’t read up much on it). Ultimately, I don’t really have a end goal besides messing around with it in different rc cars on different surfaces and at different locations.
Anyways I’m open to any inputs on my potential hardware choices and any other suggestions you guys have.
I wouldn’t own anything from Radiolink. They have been bad actors regarding the Ardupilot GPLv3 license for years and don’t deserve our $$.
Outdated and EOL. I have a Kakute F7 and it’s fine but no sense in buying one today.
The biggest generator of FC problem posts on the forum.
Go with an H7 based Flight Controller. The Matek H743 suggested is good or the Wlite version.
Do you have any suggestions for budget radio options from other brands? That does seem pretty scummy as a company.
Would there be any noticable difference between the Matek H743 Wing vs the slightly cheaper Holybro Kakute H743 Wing? I’m sort of leaning towards the Holybro so I can order it and the GPS module together.
I like Radiomaster Transmitters. They have some budget models. It’s what I use for Rovers and everything else.
The Holybro H743 would be a good choice also.
I think I might get the radio master Mt12, looks like a solid radio. Looking at getting the ELRS model with the 4in1 module so I can connect it to different receivers. Also probably gonna get the ER5C receiver to use. Based on what I read, the PWM receiver will be able to be connected to the Holybro Kakute H743 wing. One other thing I don’t know is do I need a telemetry link to link my laptop to the controller?
Wow, that runs EdgeTx, I didn’t know that. Very cool.
With most Radiomaster radios you can use the Yaapu script to get telemetry on the radio screen. Many of us use that script, it’s great. Otherwise, or also, you can use a Sik telemetry radio to get telemetry back to your Ground Station laptop. I have a Rover that uses both of these but I usually just use the telemetry on the Transmitter. What I don’t know though is if the script will work with that radio and the screen on it. You can post in the developers blog thread and ask Yaapu Telemetry script
Note: In that Blog post there is a user who tried to get the script working on that radio and I don’t see that he was successful. That was 5 months ago so you may want to post again and see if there is any progress.
For most Rovers, there isn’t much need to get super picky about the exact specs of the autopilot. H7 processor and SD card support are the real keys to be able to fully explore ArduPilot.
The cheaper boards don’t have internal compasses, so you want a GPS module that includes a compass (or even better, a dual RTK GPS config that uses moving baseline for heading - but that’s a big expense).
Radiomaster radios are King Kong in my book. And ExpressLRS supports all features. No need for multi-module support unless you have legacy vehicles to control. I’ve converted all of my stuff to use a TX16S and ELRS.
Echoing Dave a bit more, SiK telemetry is excellent for short to medium range telemetry. Most entry level (and many advanced) users won’t need more range, and the bandwidth is plenty for MAVLink.
Mostly the redundant IMUs and a slightly better barometer on the Matek. Probably nothing worth spending more money for if you’re looking to build a rover.