Poor mans RTS


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Gizmo

Admin Group

Joined: 05/06/2004
Location: Australia
Posts: 4993
Posted: 09:31am 22 Nov 2022      

  ryanm said  I would recommend going with an ardupilot brain and one of the RTK kits from HERE


Hi ryanm

Could you post that link, it didnt come up in the forum post. I've been pricing RTK kits and looking for more options.

Thanks
Glenn

ryanm
Senior Member

Joined: 25/09/2015
Location: Australia
Posts: 191
Posted: 04:34am 23 Nov 2022      

Ha! That does look like a link, but it's actually the name of the product Here 3 & Here+ RTK Base (M8P) Combo.

https://store.rfdesign.com.au/here-3-here-rtk-base-m8p-combo/

DISCLAIMER I've never actually used one of those GPS units, it's on my wishlist to replace the $20 chinese one I've got on my little plane at the moment, but I still crash to often to put that sort of money on it. You'll want to do a bit of reasearch and make sure you're getting suitable and compatible gear before buying.

A lot of the autopilots on the market are super expensive because they're made for expensive drones so they have redundant co-proccessors and sensors. If you go on Aliexpress and look for Pixhawk there are a lot cheaper ones that should (I think) be plug and play with that GPS.

Another trap for new players that got me is some of the cheaper autopilot hardware is based off an older proccessor and has a ceiling on the firmware version it can run. Although given you're using it for a mower you probably don't need LIDAR assisted landing for example so an older version might not be an issue.

ryanm
Senior Member

Joined: 25/09/2015
Location: Australia
Posts: 191
Posted: 04:51am 01 Dec 2022      

Looks like I'm a bit out of date. Been a few years since I've looked into this. There's a lot of really good info on this site about setting up a rover style autopilot.

https://ardupilot.org/rover/docs/common-autopilots.html

Gizmo

Admin Group

Joined: 05/06/2004
Location: Australia
Posts: 4993
Posted: 09:04am 06 Dec 2022      

After a few failed tests with the GPS modules, and a lot of research, I bought a ArduSimple RTK2B-F9P development module for about $400.

I found out there was a RTK CORS service about 15km away, meaning I only need one module, I can use the CORS service as the base station. The CORS service is free, you just need to set up a free membership.

The ArduSimple module arrived today. I plugged in a good GPS antenna ( the crap you pick up at clearing sales ), and used the program u-center to chat to the module via USB. Set up the CORS log in information, selected the local base station, and I got a RTK solution in about 30 seconds. That narrowed my position down to about 20cm. A few seconds later I got a lock on the carrier wave, which improved accuracy to less than 2cm. Pretty happy with that.

Next its a lot more research and testing. I'm hoping to use a ESP32 as the rovers flight computer, and I have a Pi on the network which I'll use to connect to the CORS and only send the correction data via wifi to the rover's ESP32.

BIG learning curve.

Glenn