I think this is just saying SBUS inversion could be a problem.
We don’t pull the pins high or low by default and there is no inversion HW on the Blitz because it is an F7 and doesn’t need it.
You could try changing the bootloader to pull the pins high specifically.
I am using the Matek ELRS RX but I have others that also work fine.
So, it looks like I’ve managed to solve this problem.
The ELRS site describes a similar problem, but since everything works as it should on betaflight, it must be FC firmware.
I found the line DEFAULTGPIO OUTPUT LOW PULLDOWN in the hwdef-bl.dat file and assumed that if it was deleted it might help.
Here are the steps I followed. Perhaps it will help someone else:
DEFAULTGPIO OUTPUT LOW PULLDOWN lineI could be wrong in some ways because I reached this result about a week ago. But everything seems to be correct
Hi Boris, thanks for the sleuthing. Which pins did you have your ELRS receiver connected to? Sounds like pulling pins low on UARTs is a bad idea.
Initially I connected the receiver to all possible SERIAL ports, but none of them worked. After re-flashing the bootloader, I connected the receiver to SERIAL1
Hi ALL
I’m trying to install AC 4.4.4 on Blitz Whoop F7 AIO v.1.1
and receiving the errors:
I have no problems with MCU, Gyro, Baro and any other hardware with BF. And it’s flying well
What I’m doing wrong?
Can you send a picture of the IMU? Someone else with this problem had a bad board with soldering issues
Hi @andyp1per . I saw this thread. And checked soldering - all looks fine
In this case BF should not work fine. No ?
Does BF tell you the sensor type?
Was tried to check throughout cli config - no luck.
And nothing similar in the configuration tool.
Looks like it’s somewhere in the middle of the board. Between two plates.
Otherwise I can try to install inav. As I remember it can show type of sensors
MCU F745 Clock=216MHz, Vref=3.31V, Core temp=52degC
Stack size: 2048, Stack address: 0x20010000
Configuration: CONFIGURED, size: 3067, max available: 32768
Devices detected: SPI:1, I2C:1
Gyros detected: gyro 1 locked dma
GYRO=ICM42688P, ACC=ICM42688P, BARO=DPS310
OSD: MSP (30 x 16)
BUILD KEY: 8c5b800da69469a4f4ba090cfcac4163 (4.4.3)
System Uptime: 602 seconds, Current Time: 2024-02-29T20:06:21.142+00:00
CPU:45%, cycle time: 127, GYRO rate: 7874, RX rate: 15, System rate: 9
Voltage: 1 * 0.01V (0S battery - NOT PRESENT)
I2C Errors: 7
FLASH: JEDEC ID=0x00ef4018 16M
Arming disable flags: RXLOSS CLI MSP RPMFILTER
Ok, they changed the IMU. Usually with these its a pain to figure the orientation. So I will do you a build and ask you to post a video of the HUD in mission planner as you rotate the vehicle so that we can work out what the orientation is.
Sure. that’s not a problem. But I can tell you wat it is with BF
Arrow on the board is pointing wrong direction on 45 deg
I do have board installed with MCU down side
Yeah I generally find it impossible to translate from BF to AP.
This now includes a bootloader so you should be able to update with MP once you have installed the hex.
Please orient the board in the correct direction and then show me what happens when you rotate about each of the three axes.
Based on that picture from iFlight website:
we need to rotate it 135deg CCW
I can’t disassembly drone to get real ways of things. As practice shows information on their site is wrong 
Did you try the firmware? The ICM-42688 is weird in the orientations it presents. I’m not asking you to disassemble it - merely hold the drone in an orientation that means that the board is level, arrow facing forward and uppermost. The orientation within the drone is set by a different parameter.
Yes - I’ve posted video with that. So if follow to arrow we need to rotate gyro 135deg CCW
Ok, I suspect this might be hard to get right because you have a non-standard orientation inside the frame. If you can please make sure that AHRS_ORIENTATION is correct for the board orientation - it might be something like 11 - Yaw135Roll180 - and then the rotation of the drone should be correct for the rotation of the board if we have the hwdef orientation correct.
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.
Sure’ I’ll change it. But I do have only 45 deg YAW CW rotaion from the arrow
The forward direction of the board is located diagonally across the drone (you can find that moment on video)
