Will Mission Planner NTRIP RTK injection work with a CAN based M8P GPS module like the HEX Here3?
I have a small rover I built to drive around in our back yard. No real reason other than to teach my kids about building things and because I thought it would be fun. It has a M8N which we quickly realized doesn’t quite have the precision and repeatability required to navigate effectively so I started looking into RTK.
There are a couple local real time NTRIP stations available from unavco.org which I have tested and successfully get a stream in MP. I am trying to decide on which hardware to buy and came across the HEX Here3 ($125) but since it is CAN only I didn’t know if MP could inject the NTRIP data to the receiver.
I was originally looking at the Navspark NS-HP-GN2 ($125) and the Hex Here+ ($275) but liked the cost and packaging of the Here3. (M8P module, antenna, and compass in one)
If you can afford an F9 L1/L2 based GPS, those are miles ahead in terms of RTK performances, but they cost about twice as much as a good M8 based GPS, maybe even a bit more.
Both of them can have ntrip corrections injected trough Mission Planner.
My question wasn’t which module to get, it was if MP could inject NTRIP/RTCM3 over CAN. I know if can over serial but wasn’t sure if CAN was also supported.
I made a list of F9* as well as M8P boards and found the Here3 to be the most cost effective for the features it has to offer. A F9P with dual band antenna is what I want but a M8P is what I can afford.
I answered your question and, well, if you want to buy a gps for its rtk capabilities that will almost never get a fix, expecially using ntrip and vrs than m8 is your gps
I set up the HERE3 with my PixHawk on my rover and found the configuration to be easy and straightforward. I was able to get my UNAVCO NTRIP feed working and got a RTK Float solution in quickly. It took a while to get a RTK Fixed solution and I noted it would go in and out. The nearest NTRIP base is 12.3 km away from my property which I believe contributes to the flaky fix. I am also in the city and have a 2 story house next to my property where the rover drives around which doesn’t help.
I am still testing the rover when it has a RTK Float solution and I think it is going to be good enough. (better than just a 3D Fix) I just got a ZED-F9P dev board to try but have not put it on the rover yet but I did hook it up to the uCenter program with the same NTRIP base and it came up with a RTK Fixed solution in less than a minute that appears to be very stable.
I like the packaging of the HERE3 with internal compass, antenna, and lights much more than a dev board with a separate antenna. Maybe HEX will come out with a “HERE4” that is based on the F9P.
Got it from using gps modules on the field in the last 4 years for my photovoltaic job. If you “need” rtk than there is no other choice than an f9 module, if you want to play with it than can buy anything.
Actually, the HERE3 performs much better than expected even without creating a RTK Fixed solution.
I setup my rover with the F9P configured as GPS1 and HERE3 as GPS2 and ran several waypoint missions around my yard and then calculated the distance between the reported coordinates. The HERE3 reported distance varied from the F9P +/- 0.9 feet with an average error of 0.09 feet.
I am going to do some other tests with just one GPS enabled and see how repeatable both systems are but if it works out, I will have a F9P dev board and antenna for sale. I agree the F9P is better than the M8P but it might not be worth the 2X price unless you really need additional accuracy.
I still have both the HERE3 and F9P on my rover and like I said before, I agree the F9P is better than the M8P but it might not be worth the 2X price unless you really need additional accuracy.
