Many people who followed my gps on Betaflight guide have not had the best experience with gps. Here are some tips for getting the most out of your gps setup.
- Make sure you have an m8n chip. The reason you want an 8 and not a previous version (i.e. a 7) is that the 8 can do two different satellite constellations at once. Specifically, GLONASS and GPS. You effectively double the number of satellites you can see, which makes the gps lock much faster. The way to check for this: in u-center, go to Messages View. Then select UBX -> MON -> VER.
- If your GPS takes a while to lock, you may want to power it up with 5V while you’re driving to your flying spot. Some flight controllers supply 5V when plugged in to USB (the Omnibus F4 does, for example) and others don’t. For the ones that don’t, you could attach a small connector to power it with an external 5V source.
- Mount your GPS unit such that it has as much line of sight as possible to the sky. If you have a 1.3GHZ video transmitter, get your gps as far as possible from it.
- It’s possible to use a GPS with only the RX pin of a UART, if it has non-volatile configuration. You have to first configure it via u-center so that it sends all the messages Betaflight needs (see here ). Obviously auto-config from BF won’t work, but that’s fine.
- If your gps is connected with TX and RX, you can connect u-center directly to it via the flight controller without the need for an FTDI interface. In the Betaflight CLI, type “gpspassthrough” and then disconnect so that the configurator releases the port. Go to U-center and connect to the same port.
- My two preferred gps modules so far: 1) Beitian BN-880 for 6″ and larger builds. It also has compass. 2) Ublox m8n for 5″, because it’s small and light.
[more tips to come, check this page once in a while]