I recently flashed my M8N’s to 3.01. I then got the GPS signal health bad, also compass errors and more… the quad I’m using it on still has a 3dr pixhawk and it flipped and crashed in 2 of 3 short flights after I thought I fixed the GPS message.
I read and finally found by adding more sat systems the M8N will only communicate with the pixhawk at 3khz and it needs to be at least 5khz. seems like more problems than that too. compass works fine for a long time and completes cal easily but then flips out at random.
I’m looking for replacement GPS’s. I don’t want the expense of RTK with a base station and all (maybe in time). I’m wondering if any of the M8’s will work as stand alone and be able to handle all or most of the GPS systems (GPS, SBAS, GALILEO, etc…) at least 5khz and that I can at use for a RTK setup in future. I would like to try a F9P or F9T but I’m not even sure if they would work as a standalone replacement for my M8N? id like to know if any of the M8’s would work for this too. I’m having a hard time finding this info…
The NEO-M8N has been a workhorse for the last 5 or so years. It does GPS+SBAS+Glonass at 5 Hz reliably. The biggest mistake with it is the use of a 25x25mm ceramic antenna, which you’ll find in 95% of GPS units sold. While for single band GPS or Glonass it works wonders, it’s not well suited for the wide-band dual-constellation GNSS, and it’s mediocre performance is only saved by the M8N’s excellent sensibility.
You can find units with 35x35mm antennas, which are better, and you can find units with Tallysman dual-feed circular antennas, which are perfect. My all-time favourite is the DJI Inspire2 GPS replacement part. It doesn’t include a magnetometer, tho’, so you’d have to add one yourself.
The F9P is a serious piece of hardware. Because of the multi-band antenna it’s usually big and heavy. Easily 10x as big as your cheap M8N sold everywhere.
Thanks. yes I have the 35mm patch type antennas on my M8N’s I bought them years ago from CSGshop. They worked great until I upgraded them to 3.01. after upgrading them, nothing but trouble… ive been through the settings many times and tried many things ive read on the forums. even when choosing just 3 sat systems I get bad gps health. with 2.01 I was picking up 21 sats without a problem, with 3.01 I’m having the error with even 17 at times. maybe even less.
the really weird thing is Im having compass errors after the upgrade and I dont think that should have anything to do with the gps settings??? Compass uses I2C? IDK but I had 2 flips and crashes since doing the upgrade. IDK, it may be the pixhawk. It is an original 3dr Pixhawk and I haven’t flown these in a while so they never ran the newer firmware. IDK if that’s a problem or no??? Looking at the log, it looks like I had IMU errors art the time of flip.
Anyway, I ordered a couple CUAV v5+ and the F9P GPSs to make a base station. I haven’t started reading about getting these set up yet but with any luck I will. It looks like you can use the M8P for RTK but Im not sure if Ill be able to use the M8N for the copter side?
Ive got a lot to learn, so much has changed since i last messed with these.