The digital OSD has no serial port to talk through
What ArduPilot says:
- MSP backend not available
- MSP DisplayPort uart not available
OSD_TYPE (or OSD_TYPE2) is 5, MSP DisplayPort: the OSD that DJI, HDZero, Walksnail and similar digital video systems draw themselves from data the flight controller sends. At start-up no serial port was found with the DisplayPort protocol, so the OSD did not start and the goggles show no flight data. “MSP backend not available” means this firmware has no MSP support at all.
What to do, most likely first
The port the video unit is wired to is not set to DisplayPort.
CheckFind the UART the video unit's TX and RX go to (the Board & Wiring Planner shows which pad is which UART): its
SERIALn_PROTOCOLmust be 42 (DisplayPort), not 32 or 33.FixSet that port's
SERIALn_PROTOCOLto 42 and reboot.The video is analog: the board draws the OSD with its own chip.
FixSet
OSD_TYPEto 1 (MAX7456) and reboot.The firmware was built without MSP.
CheckThe Firmware Inspector lists what a firmware file was built with.
FixBuild a firmware with MSP and the DisplayPort OSD.
Parameters to look at
| Parameter | What it is |
|---|---|
OSD_TYPE | OSD type |
OSD_TYPE2 | OSD type 2 |
SERIAL1_PROTOCOL | Telem1 protocol selection |
SERIAL2_PROTOCOL | Telemetry 2 protocol selection |
SERIAL3_PROTOCOL | Serial 3 (GPS) protocol selection |
SERIAL4_PROTOCOL | Serial4 protocol selection |
SERIAL5_PROTOCOL | Serial5 protocol selection |
Where to do it:Board & Wiring PlannerFirmware InspectorFirmware Builder
The code that sends it
MSP backend not available
libraries/AP_OSD/AP_OSD_MSP_DisplayPort.cpp AP_OSD_MSP_DisplayPort::init() · Open in ArduPilot Copter-4.7.1
MSP DisplayPort uart not available
libraries/AP_OSD/AP_OSD_MSP_DisplayPort.cpp AP_OSD_MSP_DisplayPort::init() · Open in ArduPilot Copter-4.7.1