Newbee to the Ardupilot world. I’ve been working on robot lawnmowers. But on a budget. I have an older Robomower that is pretty simple. I’d like to use RTK GPS and Ardurover to eliminate the perimeter wire and mow in stripes, rather than random. I/O is simple. A bumper switch, a “lift” switch if the mower gets lifted, two 24V DC motors and 3 blade motors. I’d like to add a sonic obstacle sensor as well. Looks to me like I need a flight controller (perhaps the Pixhawk), RTK GPS (perhaps The Holybro F9P), 900mhz radios. Use the Ardurover software and Mission Planner. I have an airport nearby (Florida) and it has the NTRIP RTK corrections available for free, which I understand Mission Planner can use to correct the RTK GPS to 1cm accuracy. Do I have the overall building blocks right? Anyone care to add from your experience specific models of hardware, caveats, warnings? I’m on a budget and cheaper versions of everything would be appreciated. The Pixhawk can be mini or needs to be the 6C or 4 pro, or what? RTK GPS is what version? F9P? Anything better or cheaper? I’m in the US (Florida), and local station does not have the Russian GNSS system, but does offer NTRIP for the other 3. Any youtubes you guys particularly like?
If this post is not in the right place, please help me get it there.
Hey Mark. You have the basics right. Get a FC (I use Cube Oranges) two F9Ps (I like SparkFun F9P SMA. One for rover location, one for rover yaw), and BECs as needed. Local NTRIP w/o Russian GNSS is plenty and works well with MP. Couple of Holybro 913mhz radios for telemetry (with good antennas) and you are in business. Go to. ArduPilot Rover — Rover documentation and start reading. Warning: Skipping steps will waste loads of your time. Good Luck!
Can’t go wrong with that advice!
I tend to use ArduSimple’s SimpleRTK2B boards, but they are essentially the same as the Sparkfun offerings. If you explore ArduSimple’s website, DO NOT be tempted by the “SimpleRTK2B+Heading” kit. It’s slick, but it’s not well suited to ArduPilot (and it’s more expensive than just two of the basic boards).
Another option that is less well known is CUAV’s new-ish C-RTK 2HP. I have one and still owe it a thorough review, but it really worked well on the bench, and I look forward to using it on a vehicle. It’s about half the cost of the Zed-F9P option(s).
915MHz telemetry will almost certainly get you what you need. There are other options, but the ones Steve mentioned are well supported and reasonably affordable by comparison.
Don’t skimp on the autopilot. Use an H743 or H757 based board like the Cube Orange/Orange+, Matek H743 Wing, or QioTek ZealotH743. You’ll almost certainly want the full feature set afforded by recent versions of ArduPilot and potentially want to do some scripting-enabled functions. Anything less than an H7 will hamper that.
You’ll also want an RC transmitter/receiver combo that’s worth using. I strongly prefer ExpressLRS via the Radiomaster TX16S and Matek or Happymodel receivers. It supports “Yaapu telemetry” which is extremely useful with ArduPilot. ExpressLRS is far from the only option, but I stand by my recommendation.
Heed Steve’s advice - read the docs. Read more. Skip nothing. Ask questions!
Hey, Yuri. Any further ideas about the CUAV? Apparently dual GPS, with compass? Getting heading from the dual GPS seems better than a compass onboard, and the combination of both may be the best. Any real life experience? The LC29 is a great idea but having some concerns about reliability. Might be worth it to do an upgrade?
Any GPS module from CUAV runs rings around the cheap Quectel stuff.
The specs say 0.2 degrees accuracy in Yaw if the two gps antennas are spaced 1m apart. That sounds truly awesome. Can ardurover, without mods, use the dual antenna, single processor directly to get yaw/heading? Would that help a mower do neat rows? I assume you didn’t have the time to get it into the field for testing? It looks fairly cost-effective, since it seems to include two helical antennas, a RM3100 compass and some cables, probably $100 worth of extra “stuff”. It doesn’t use the Ublox F9P though. Again, it has a “new” processor. Better to just get two Zed F9P’s–at twice the cost?..
It works fine and is supported.