Passthrough fails with "ACK_D_GENERAL_ERROR" on SPEDIXF405 with INAV 8.0.0 #2399
Description
Problem Description:
After flashing my SPEDIXF405 flight controller with INAV, the Passthrough functionality to my ESCs fails. The ESC configurator (both web-based and desktop versions) can detect the presence of the motors but consistently receives a ACK_D_GENERAL_ERROR when attempting to read or write settings. The CLI command set motor_pwm_protocol has been set to STANDARD, MULTISHOT, and ONESHOT125, but the issue persists. A full chip erase and re-flashing did not resolve the problem.
Crucial Finding:
This issue is specific to INAV. When the exact same hardware stack is flashed with Betaflight, the Passthrough functionality works flawlessly, allowing me to read and configure the ESCs without any errors. This indicates the problem is not with the hardware (FC, ESCs, or wiring) but with the INAV firmware itself.
Steps to Reproduce:
Flash a SPEDIXF405 flight controller with INAV 8.0.0.
Connect to INAV Configurator and go to the CLI.
Enter the following commands:
set motor_pwm_protocol = STANDARD (but i use for my preset DSHOT300)
save
Disconnect the FC and close INAV Configurator.
Open an ESC configurator (e.g., esc-configurator.com or BLHeliSuite).
Connect the FC and attempt to read the ESC settings. The operation will fail with the ACK_D_GENERAL_ERROR(BLHeil) or cmd_DeviceInitFlash if we are using ESC configurator.
Hardware and Software:
Flight Controller: AxisFlying Argus F405 (using the SPEDIXF405 target)
ESCs: AxisFlying Argus F405 ESC (BLHeli_S / BlueJay firmware)
Firmware versions tested:
INAV 8.0.0 (fails)
Betaflight (works)
Operating System: macOS