1. Run `nix build .#packages.armv7l-linux.fast-servo-sd-image` to build the sd card image.
2. Run `nix develop` to build a dev shell to access the GUI.
### Flashing
1. Plug in your SD card to your computer and run `lsblk` to locate SD card
2. If there are any partitions on the SD card, run `umount <mount point>` all the related mount points.
3. Run `sudo dd if=<path to the SD Card Image> of=/dev/<SD Card Device Name in lsblk> bs=4M status=progress oflag=sync`
4. Eject the SD Card before removal
### Usage
1. Make sure the onboard DIP Switch is in the following condition.
- EN: OFF
- MODE: ON
2. Install the SD Card, power up the board via the power jack or PoE and plug in the RJ45 Ethernet cable.
3. Wait for all the front panel LEDs except the termination status LEDs to turn off. It can take a minutes or two for first boot. If it does not boot up, try to flash the SD Card again.
4. By default, linien-server starts up automatically. In case linien-server crashes, it will restart itself. Logs are stored in `/root/linien-server-log`. Here are some commands to interact with the linien-server service once you `ssh <fast servo ip address> -p 3030` into fast-servo.
| Start the linien-server service | `linien-server start` |
| Stop the linien-server service | `linien-server stop` |
| Check if the linien-server service is running | `linien-server status` |
| Set the linien-server service to start at bootup | `linien-server enable` |
| Set the linien-server service not to start at bootup | `linien-server disable` |
4. In the dev shell, run `linien` to launch the GUI. Add new device. Username is `root` and it does not take any password to log in. You leave the password field with any text.
5. Select the newly added device and click connect in the GUI to connect and start the GUI.
