VOXL Flir UVC Video Streaming (RTSP)
Table of contents
Overview
This user guide provides the necessary steps to stream Flir Boson or Lepton over RTSP network using the USB UVC interface and the VOXL system.
In short, we’ll be doing the following:
- Connect a Flir USB camera to the VOXL’s V2 Debug Board
- Use voxl-streamer on the VOXL to stream the video to the host computer
- Use either VLC or QGC on a host computer to view the video stream
Requirements
Hardware
| Part Number | Description | Link |
|---|---|---|
| Host Computer | Ground Control Station (Ubuntu 18.04) | |
| VOXL-DK | VOXL Development Kit | Purchase |
| MPS-00001-1 | 5V/6A Power Supply | Purchase |
| MCBL-00009-1 | USB Cable (Host, 4-pin JST to USB 2.0 Type A Female) | Purchase |
| Flir Boson or Flir Lepton |
Boson
The Boson requires more current than the USB 2.0 standard supports. To achieve this current, the power and ground can be connected separately in a “y-cable” to an alternate 5V power source. Alternatively, ModalAI has a debug board with a direct connection to the core 5V supply on VOXL which provides enough current. This Debug Board V2 can be found below.
| Part Number | Description | Link |
|---|---|---|
| MDK-M0078-2 | VOXL Debug Expansion V2 Add-on | Purchase |
Lepton
One of the following VOXL Add-on boards is required.
| Part Number | Description | Link |
|---|---|---|
| MDK-M0048-1-01 | VOXL Microhard Modem Add-on | Purchase |
| MDK-M0017-1-01 | VOXL USB Expansion Board with Fastboot and Emergency Boot | Purchase |
| MDK-M0030-1-01 | VOXL Cellular LTE and USB hub add-on | Purchase |
Target Software
VOXL-SDK version XXX or greater.
Host Software
- On the host computer, install VLC media player, which we’ll used to display the RTSP video:
sudo apt-get install vlc
Setup Hardware
- Disconnect power from the VOXL
- Attach the Debug Board to VOXL J13
- Attach the JST cable to the JST USB connector
- Set the jumper to 5V APM setting
- Attach the Flir camera to the USB connector on the JST to USB Female A cable
- Connect power to the VOXL

Network Configuration
- Configure the VOXL as an Access Point (or connect it to a network)
- instructions on how to do this are here
- the default IP address of the device will be
192.168.8.1
- Connect the host computer to the VOXL’s Access Point (default password is 1234567890) or to the same network you connected the VOXL to
Run Software on Target
voxl-uvc-server
- SSH onto the target (see here for details) or ADB in using a micro-usb to USB cable
- First, validate the the USB device is found using the
lsusbcommand:
root@apq8096:~# lsusb
Configure voxl-uvc-server
Start voxl-uvc-server with the following command
Boson:
voxl-uvc-server -r 640x512
Lepton:
voxl-uvc-server -r 160x120 -f 9
More details in the voxl-uvc-server documentation.
Configure voxl-streamer
Start voxl-streamer with the following command
Boson:
voxl-streamer -c uvc-flir-boson
Lepton:
voxl-streamer -c uvc-flir-lepton
More details in the voxl-streamer documentation.
Viewing Stream
VLC
On the host system, run the VLC software
Go to
Media > Open Network StreamEnter the following URL:
udp://@:4242Click
Playto view the video stream
QGroundControl
Before attempting to view the video stream, follow these instructions on connecting to QGC: How to Connect QGroundControl to VOXL using WiFi
After your connection has been established to QGC, press the purple QGC logo in the top left corner in order to access the
Application Settingsmenu.Under the
Generaltab, scroll down until you find theVideosection.Under the
Video Sourcedropdown, chooseRTSP (h.264) Video Stream.In the
UDP Portfield enter the default:4242You will now be able to view the video stream under QGC’s
Flyview.
Next: Connecting VOXL to Flight Core