@geofrancis any latest update, also need to have a word with you regarding skytrq ? do you have discord ?
@geofrancis did you ever get these $50 Skytraq RTK receivers working? I am looking at setting up a mower and trying to cost out the most economical solution
I havenāt replaced mine after I damaged it, itās on my list for the summer. it has been documented to work with ardupilot so i dont see any issues using it. your probably best to use a pair and run your own base station or get the l1/l2 version at 100usd if you want to use online ntrip servers as i dont think many do l1/l5.
rtcm injection over mavlink supposedly works too so you only need a single telemetry radio.
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Iām considering biting the bullet, but might go ahead and order 10 if there are others interested in splitting shipping cost. (I need 2) Of course, would be re-shipping once they arrived, but for ground shipping, would only be $7ish. So $65/10 + $7= $14ish on top of the $50 for the module.
Looking at NS-HP-GN5 : PX1125R L1/L5 RTK BREAKOUT BOARD since Iāll be running them through a ESP32. (Choosing the L5 model since enough sats should have L5 support in the next year or two, and L5 is the future. Also cheaper, since Iāll be running my own base station)
Let me know if you are interested, and if enough folks are, Iāll do an order.
@geofrancis good to see all your posts and the details which you shared about gps sensor. I am looking for a gps sensor with 1 cm accuracy. Was wondering if you can suggest me any good option, please. I am in the US, so assuming it wonāt take much longer in shipping.
can someone elabrate on how the module worked out I am considering is buying a setup too - just because of cost - good price for a hobbyist but I do not want to collect another forever (parts and project) .
can someone elabrate on how the module worked out I am considering is buying a setup too - just because of cost - good price for a hobbyist but I do not want to collect another forever (parts and project) .
Sorry, I havenāt yet ordered anything. My purpose is precision surveying, and there are enough resources online that I feel pretty confident that this module will work without an issue. I just donāt foresee having enough time in the near future to invest in the project.
I purchased the PX1122R L1/L2 RTK Breakout Board back in June 2023 and combined it with a SparkFun Serial Basic Breakout -USB-C module, a Sik 915 MHz telemetry radio and a Beitian BT-160 Survey Grade L1/L2 antenna to build the Rover portion of my diy autonomous robot lawnmower.
The Breakout Board uses the Sik telemetry radio to receive RTCM correction messages from my Base Station. The Beitian BT-160 is a less expensive alternative to the Sparkfun Survey Grade antennas and provides similar performance.
I have no trouble getting and maintaining a Fix solution with the Breakout Board when used in conjunction with my Base Station. The GNRMC messages from the Breakout Board are sent over the USB-C connection to a Raspberry Pi 4B running the Donkey Car path_follow.py template which provides steering and throttle output to drive the lawnmower over a prerecorded path to mow my lawn.
Works great.
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@TCIII thanks for sharing your experience. Iād also go for a dual-freq receiver cause the L1 band can be easily spoofed or jammed.
I have a question to clarify on how to extract the precise positions after RTK corrections have been applied: do I understand correctly that once you feed RTMC messages to your rover (via the UART RX pin), you simply read NMEA messages (in particular, GNRMC) that the rover outputs?
@dizcza,
Yes, the Donkey Car path_follow.py template, running on the Roverās RPi 4B 4GB, receives only the GNRMC message at 115200 baud over a USB connection and uses the GNRMC message to accurately determine its lat and lon position.
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