VOXL 2 PX4 Developer and Build Guide
Introduction
Since not all support for QRB5165 has been integrated into the mainline PX4 source code ModalAI maintains a fork of the project where our custom additions are kept. The intention is to eventually merge all of these customizations into the mainline PX4 source repository so that our fork will no longer be necessary other than for research and development purposes.
Main components
- The PX4 firmware lives in a fork of the main PX4 firmware repository
- The voxl-px4 project is a wrapper that includes the PX4 firmware as a git submodule. The main objectives are to provide packaging and installation support.
- The build environment for QRB5165 is encapsulated in a docker image. This docker includes an ARM64 toolchain from Linaro to build the code running on the applications processor and a Hexagon DSP toolchain to build the code running on the SDSP. The Hexagon SDK is only available directly from Qualcomm so instructions are provided to obtain the SDK and integrate it into the build environment docker image.
Links to source code
- voxl-px4 wrapper project which runs the main service across Linux and sDSP.
- Development Branch on ModalAI’s VOXL 2 PX4 Fork which has the latest source code for the PX4 build for VOXL 2.
- Docker image to build PX4 for VOXL 2 and RB5 Flight sDSP and CPU
DSP Debugging
mini-dm
mini-dm is a diag log tool for debugging the shell output of the Hexagon DSP. mini-dm is a part of the Hexagon SDK.
To configure on Ubuntu:
lsusb and find the Qualcomm entry.
VOXL’s device ID is 05c6:901d Qualcomm, Inc.
Add the udev rule with the following command:
echo 'SUBSYSTEM=="usb",ATTRS{idVendor}=="05c6",ATTRS{idProduct}=="901d",MODE=="0666"' | sudo tee -a /etc/udev/rules.d/70-android.rules
Then reload udev rules or power cycle the voxl
voxl2:/$ udevadm control --reload-rules && sudo udevadm trigger
To execute mini-dm extract the dsp sdk and run on host machine:
sdk/x.x.x/tools/debug/mini-dm/UbuntuXX/mini-dm
mini-dm Ubuntu18 has been verified to work on Ubuntu24
Then on voxl run px4 dsp commands such as:
voxl2:/$ px4-qshell crsf_rc status
The output will show up in the mini-dm console
[08500/01] 51:17.578 0068:01: SDSP: [uORB] Marking DeviceNode(qshell_req) as advertised in process_remote_topic 0632 uORBManager.cpp
[08500/01] 51:17.580 0049:01: SDSP: [qshell] qshell gotten: crsf_rc status 0088 qshell.cpp
[08500/01] 51:17.580 0049:01: SDSP: [qshell] arg0 = 'crsf_rc' 0163 qshell.cpp
[08500/01] 51:17.580 0049:01: SDSP: [qshell] arg1 = 'status' 0163 qshell.cpp
[08500/01] 51:17.580 0049:01: SDSP: [crsf_rc] UART device: 7 0582 CrsfRc.cpp
[08500/01] 51:17.580 0049:01: SDSP: [crsf_rc] UART RX bytes: 43316 0583 CrsfRc.cpp
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