> For the complete documentation index, see [llms.txt](https://gcs.gitbook.io/uno/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gcs.gitbook.io/uno/setup-companion-computer.md).

# Setup companion computer

These guide describes how to setup any Linux-based computer as a companion one. It can either be your laptop or headless Raspberry Pi on the ground or micro-PC onboard.

### How it works <a href="#how-it-works" id="how-it-works"></a>

Telemetry messages got from autopilot board over serial or USB port, by wires or radio link,  then a small script transmits these messages to GCS.uno server. When you open GCS.uno dashboard in a web-browser, this telemetry is got from server and rendered to a screen almost in realtime. In opposite direction, you press an action button on a web-page, this magically transforms to a MAVLink message and reaches onboard autopilot to be executed.

Assuming you have your computer running with internet connected and command shell available.

### Install MAVProxy

[MAVProxy](http://ardupilot.github.io/MAVProxy/html/index.html) is a fully-functioning command-line GCS for UAVs. It is used to proxy one telemetry source to many different locations. For example, one for [GCS.uno](https://www.gcs.uno) script, one for [ROS](http://www.ros.org), and another one for [QGroundControl](http://qgroundcontrol.com) in local network.

Follow [official MAVProxy manual](http://ardupilot.github.io/MAVProxy/html/getting_started/download_and_installation.html#linux) to install it on your system.

### Telemetry source

If companion computer is placed onboard, it likely communicates with autopilot over serial (UART) port. Here is a good example of [configuring Pixhawk with Raspberry Pi](http://ardupilot.org/dev/docs/raspberry-pi-via-mavlink.html). Radio modems can be connected either over serial or USB port. Follow modem's manuals to connect it to your computer.&#x20;

#### Serial port

Check it with MAVProxy:

```
sudo -s
mavproxy.py --master=/dev/ttyAMA0 --baudrate 57600
```

This command makes MAVProxy listen serial port 0 for telemetry messages and show autopilot's status messages in console. The same source will be also for a radio modem, connected over serial port.

#### USB port

Check it with MAVProxy:

```
sudo -s
mavproxy.py --master=/dev/ttyUSB0 --baudrate 57600
```

#### UDP port

MAVProxy can also listen to local UDP port:

```
mavproxy.py --master=udp:127.0.0.1:UDP_PORT
```

If MAVProxy successfully connects with your autopilot continue with installing GCS.uno board scripts.

### Install additional dependencies <a href="#install-additional-dependencies" id="install-additional-dependencies"></a>

#### NodeJS <a href="#nodejs" id="nodejs"></a>

```
curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -sudo apt-get install -y nodejs build-essential
```

#### PM2 process manager <a href="#pm2-process-manager" id="pm2-process-manager"></a>

```
sudo npm install pm2 -g
```

### Download and install board scripts <a href="#download-and-install-board-scripts" id="download-and-install-board-scripts"></a>

```bash
cd
git clone https://github.com/GCS-uno/drone_board.git
cd drone_board
npm install
```

Inside `drone_board` directory you can find two shell scripts `mavproxy.sh` and `video.sh` which help running MAVProxy and video streaming. If you are sure not to use them, just skip to next step, otherwise make them executable:

```bash
chmod +x mavproxy.sh
chmod +x video.sh
```

### Get your drone keys <a href="#get-your-drone-keys" id="get-your-drone-keys"></a>

Sign in to your [GCS.uno dashboard](https://pilot.gcs.uno/), add new drone and get its MAVLink and Video keys.

![](/files/-LK2Qh4MRLu-L4lGaY7i)

Then put them in following commands to be readable by scripts. For MAVLink key (replace `abcd1234` with one copied from dashboard):

```
DRONE_MAVLINK_KEY=abcd1234; echo "export DRONE_MAVLINK_KEY=$DRONE_MAVLINK_KEY" >>~/.bash_profile && source ~/.bash_profile
```

The same for Video key (replace `abcd1234`):

```
DRONE_VIDEO_KEY=abcd1234; echo "export DRONE_VIDEO_KEY=$DRONE_VIDEO_KEY" >>~/.bash_profile && source ~/.bash_profile
```

### Start board scripts <a href="#start-board-scripts" id="start-board-scripts"></a>

Open `mavproxy.sh` file and put in MAVLink source in right way described above:

```bash
nano mavproxy.sh
```

Then check how it works

```
./mavproxy.sh
```

If it looks good `Ctrl+C` to exit and then run it in background with PM2 process manager:

```
pm2 start mavproxy.sh --name mavproxy
```

Now run `drone.js` to check connection with GCS.uno server:

```
node drone  
```

If it reports that connection is established, `Ctrl+C` to stop and run it again with PM2:

```
pm2 start drone.js --name drone
```

#### Enable scripts to start on system boot <a href="#enable-scripts-to-start-on-system-boot" id="enable-scripts-to-start-on-system-boot"></a>

Enable PM2 to start on boot:

```
pm2 startup
```

This will prompt a `sudo` command which must be copied and executed to enable autostart. Then save list of active processes:

```
pm2 save
```

And check it:

```
pm2 list
```

Now check your GCS.uno dashboard, you can see you drone's telemetry streaming.