Thanks so much!! Lots there for me to work with.
Run through the MP esc calibration again just powered by the battery
I loaded a new USB driver (via your post here, Need help with telemetry to connect to mission planner CP210x Universal Windows Driver v11.0.0), and now have MP connecting via radio telemetry 
. I ran through the MP esc calibration just using battery power & telemetry, and although it avoided the yellow flashing lights again, it still does not make the “do-do, dooo” happy beeps to say the esc has been calibrated.
Each time I now power up the drone:
- If the transmitter is already switched on with the throttle on max – lights flash blue-read
- If the transmitter is already switched on with the throttle down on zero – lights flash double yellow
- If the transmitter is switched off at point battery plugged in– lights flash double yellow
All of those light setting remain if the transmitter setting is changed after battery is plugged in (eg moving throttle up/down)
arm the drone by moving the stick down to the right. (Disarm by down/left.)
Sadly moving the stick down, down-right, or down-left all seem to have no effect (incl on the motor beeping, which I think stops once armed). This is whether or not the transmitter was switched on before or after the battery was plugged in; & whether the throttle was on max/top or zero/bottom when the battery was plugged in (each combination tried multiple times)
Then try the MP Motor Test
Every motor test option (each individual or Test-all), failed, with the error “Command was denied by autopilot”
Verify that your ESCs are wired correctly to the PDB and each ESC signal wire is in the proper location in the Pixhawk servo outputs with the GND wire up
The ESCs visually look like they are soldered onto the PDB securely, and each motor is beeping and twitching, so it seems like each is getting power (via the escs). I’ve checked the ESC signal wires are all per the dojofordrones video (ie ground up, MAIN OUT plugs 1-4, which is aprox half was along the rail)
Some SD cards won’t work well with this application. Make sure you are using a good quality SD card
I’m using the one provided by Caleb as part of the purchased dojofordrones kit, so all the hardware should be OK. It’s Gigastone Full HD Video 16GB UHS-I
try re-writing the card image with the RPi Imager
I’ve used the RPi imager, and added in the ssh and wpa_supplicant.conf files. Unfortunately, issue #5 (Raspberry pi lights go off 2-3 seconds after powering on) still happens and it all seems to be completely dead after that. I’ve plugged the battery in with no SD card, so see if the symptoms are the same -to test if it could be due to a poor SD card connection- but the symptoms there are completely different (red and yellow lights stay on), so we can rule out poor physical connection.
Use Advanced IP Scanner to check it’s connected.
It’s not – also doesn’t work on PuTTY using pi@raspberrypi.local on port 22
If not, then it might be a hardware issue or your wifi signal strength is low.
I’ve been doing all of this about 2 feet away from our wifi router, just in case that had been the problem, unfortunately not. Hardware was all from Caleb, so unless damaged in the post, it should be OK (box did not appear damaged).