I’ve had to replace the flight controller in my TRex 500 heli. The replacement is a Matek H743WING, which is what I’m using in a couple of other helis.
The heli in question has flown successfully for about 2 years and, since nothing has physically changed since its last flight with the old FC (it didn’t crash), I loaded the previous param file into the Matek before configuring accelerometer, changing a few parameters such as FC orientation and servo functions, and calibrating radio and checking flight modes. All appears to me to be well, with controls and corrections working as expected, but I cannot get it to arm; just the “nee-nah” tone when I try.
I set the logging to disarmed, so any ideas why, it won’t arm please?
Thanks Allistair. It was outdoors, but between two houses. But the log indicates the number of sats is up to 9, which I though was enough, and HDOP is below 2 which I also thought was good.
I’ve just done another check in the back yard, and the log now shows up to 11 sats and a HDOP around 1. But still not arming.
2024-03-01 08:27:17.599 Arm: GPS 1 still configuring this GPS
2024-03-01 08:27:17.599 GPS 1: u-blox solution rate configuration 0x08
Not sure if this will fix it or not, but I see you have two serial ports set up for GPS (serial 3 and serial 4), but I’m guessing you aren’t running dual GPS. If you only have one GPS then select the port that does not have the GPS and set SERIALx_PROTOCOL,-1
Thanks again Allister. I did notice that there’s two ports set as GPS, but I left it as is because that was the default. I’m only using one GPS – same as with my previous FC – so I’ll disable whichever of those ports is not used.
I thought that using the previous params would save me some time setting up the heli, but maybe I’ll just have to start the setup from scratch if that fails.
As you suggested, I checked the serial ports and found that Serial3 is the one that GPS is using. However I also checked the param files from my other two helis that are using this FC board and saw that they both had Serial3 and 4 configured for GPS, So on this one I reverted both ports back to GPS-enabled.
The good news is that in a quick test outdoors this afternoon I was able to arm and run the motor Looking at the log, the big difference from yesterday is that within about 30 seconds the number of satellites jumped from 7 (the number I got indoors) to 13, then to 15 and 16 – compared with a maximum of 11 yesterday. The log was showing 14 when I first armed and ran the motor.
It was a lousy day yesterday, though not actually raining when I ran the tests. Today is much the same, though maybe a bit more clear sky. The GPS unit is a Matek M10Q, compared with M8Q I was using with the old FC. Is it known to be any more or less sensitive than the M8 series?
Anyway, thanks for supporting me in this; It helps to talk!
My unscientific experience with the M10 is they seem to get a position faster and when compared to the M8. I’ve also been getting satisfactory positions with the M10 when I’m in locations that the M8 would struggle with. But that’s just been observations and could be a lot of other factors involved.
Which GNSS provider/system you are using?
Frequently it is better only to use provider.
The differnt systems are not linked together. For a good position your receiver has to use minimum 4 sats of the same system.
So if you are using all providers and your receiver sees 11 sats this are probably sats from three or four different systems.
I’m using only GPS. My son-in-law, who works in the telecoms and satellite business, steered me away from using Galileo because he said it’s still ‘work in progress’ since the UK left the EU! And I don’t trust the other ‘foreign’ ones.
Looking at the log, the big difference from yesterday is that within about 30 seconds the number of satellites jumped from 7 (the number I got indoors) to 13, then to 15 and 16 – compared with a maximum of 11 yesterday. The log was showing 14 when I first armed and ran the motor.