Mavlink Ardupilot Telemetry and HD video via LTE (4G):

Introduction

This is based on my project MavlinkGPRS flying with 2G telemetry link, but this time I want to ad HD video streaming also and thus stepping up to 4G (LTE).

The hardware is build from standard components and put together with som 3d-printing to give the camera a "Run-Cam" look.

Video Demo from testing:

Youtube link

Features:

• Record video up to 1920p30 / 720p60.
• Stream video to groundstation via 4G LTE network. (Lagenchy ~0.7s).
• Output analog video.
• Input Mavlink telermetry for digial OSD using the OpenHD
• Camera size: 103x35x28mm (not including antenna).
• Groundstaiton shares video feed via RTSP protocol using the rtsp-simple-server project.

Air Hardware (Drone side):

For instructions on how to setup air side see here.
The air side consist of the following hardware:

1. PCB antenna 4G - Manufacture: Siretta Partnumber: ECHO14/200M/UFL/S/S/15
2. 4G LTE usb modem with Quectel EC25 module. The model depend on your contry. It can be bought here
3. Arducam B0262 Camera including flex cable.
4. Raspberry pi Zero.
5. Input PSU, Manufature: TRACO Partnumber: TSR 2-2450

The LTE (4G) modem:

In order to get the highest bandwidt possible with LTE, a Cat. 4 modem (150Mbps/50Mbps Down/Up) must be used. This gives a maximum max upload of 50mbps and depending on the video settings, a maximum of ~10Mbps should do. Currently I use the Quectel EC25-E because i live in the EU. These can be found on Aliexpress for around ~$50 in a fairly small formfactor where I can use my own external antenna.

Raspberry Pi Zero:

Currently testing with Raspberry Pi Zero, and by using the CSI-2 interface and onboard HW video encoder I get 1920x1080 30fps without any problems. The total CPU usages is arround 20-30% inkl. the program which handles data transmission. The Pi uses the lates Buster image with this program installed.

The Camera:

Well the standard Raspberry Pi camera v1 and v2 are not very good, but they can be used. I currently use a Arducam B0262 it is the same image sensor IMX477 as the new raspberry pi HQ camera, but the formfactor is smaller (same as RPI CAM v1/v2) and more importantant, the Lens can be swapped for a wide ranges of M12 Lenses.

Ground Hardware (Ground side):

At the moment the ground station consists of two Raspberry pi's. One for receieving and displaing video with OSD (from the OpenHD project) and one which records the HDMI output and makes the video available to multiple clients via RTSP, based on the rtsp-simple-server project.

1. Raspberry pi 3b+ as groundstation running OpenHD buster v2.0.8 with modification. See here for setup.
2. Raspberry pi 3b+/4 as groundstatin recorder and video server. See here for setup.

OSD (OpenHD/QOpenHD):

The OSD is just very nice, and it can easilly be costemizes on the fly using the mouse, see more Here: OSD without video: OSD and video:

How to Build

Start with the ground pi for recording, since it is needed on the network to install the air side.
-For instructions on how to create the ground-side SD card see Here
-For instructions on how to create the ground-side OpenHD SD card see Here
-For instructions on how to create the air-side SD card see Here.