If follow to arrow direction and when picture of arrow on top then works fine.
But I hate this board. because motor numbers are wrong. Like M1 from left side but should be from right side
If we assume that arrow should be from down side and motor mounts are right then
“Here is a firmware using the existing bmi270 which uses ROTATION_ROLL_180_YAW_135 - lets see what that looks like. Firmware is in the same place.” - must be rotated on 180 deg YAW
So this is with the latest firmware that I posted? That was 135 yaw only, so its basically 180 yaw out, so 315 should work. This video is with AHRS_ORIENTATION = 0?
Here is firmware using ROTATION_YAW_315:
Video was with 2nd attempt.
With 3rd one it works fine when arrow up and forward. But motor pads are wrong.
I’ll check latest in nearest hour
For latest one I have to use AHRS_ORIENTATION Yaw90Pitch180 to get it works in normal way
Arrow looks forward and down. Motor pads are on their places.
Video https://photos.app.goo.gl/BmoDV2wZwZ4juzUL8
Pen is showing nomal board direction 
Ok so the hwdef orientation is still wrong if you need that AHRS_ORIENTATION to get the correct behaviour. Ignore motor order for now its the board orientation that is important. So I guess we need to subtract one from the other. Here is Roll180Yaw315:
Hi, im following this thread. i think i have the same issue.
We have the same problem. I’m following this. thanks.
I tried this firmware. Yes , it went past the INS error unable to initialise driver. i am now having response on Baro, Acc and Gyro.
GPS is detected but the Compass is not detected. I am using a Foxeer M10Q-250 connected to Serial4=T4R4(indicated on the board)
Current issue:
*ELRS connected to Serial3. upon powering up the drone via battery, the green led indicator is instantly solid ON. The only way for me to connect my TX to the ELRS receiver is by doing this sequence.
*Second issue, i have a Holybro SiK telemetry radio V3 connected on Serial7. Cannot establish Mavlink connection. This was working when i was using Betaflight firmware.
Betaflight: All functions are working before i switched to Ardupilot Firmware.
GPS + Compass = OK
ELRS = OK
Mavlink (SIK) = OK
Works as should be with AHRS_ORIENTATION = 0
Compass is not part of this version of firmware - you need to use custom build. But @andyp1per is it possible to enable compasses by default? I’ve recieved build with good size for that MCU
Includes compass probing and makes sure gpio pins are low on boot
Did you change which port is using serial protocol 23. I don’t know what you mean by “solid on” - what is the actual issue?
Yes I did change the protocol to 23.
Sorry for not being clear.
The led indicator on elrs is usually blinking upon power on and waits for TX to connect to it.
But in this case, the elrs rx module’s led indicator is instantly solid ON (it never blinked) when battery powered.
I think someone said that ELRS does this if the UART pins are high on boot. Try the new firmware and see if it helps.
Ok … and updated to enable the OSD as well - same location
Same problem with ERLS as @SiegFPV has. With latest firmware.
Im using UART4 for the reciever.
I’ll test and see if this version works. 
Thanks
You should not really use UART4 as it does not have DMA. I do not know what the solution is to the ELRS issue. We could try bootloader high I suppose
That’s sad. May be next time when it will require service I will resolder this. Thanks for that note
So this version defines the UART pins on 3/4 and as output high in the bootloader - it might avoid the RX going into bootloader mode. Please try. You will need to flash the hex as you need the new bootloader.