Since we added sensors to the system it is also great to have some output to show their data. That's why we added a LCD to show what is currently meassured.
## Setup
You can find the code for the LCD in [scripts/lcd](https://gitlab.hrz.tu-chemnitz.de/vws-demo/vws-spielwiese/-/tree/followup/demonstrator_config/scripts/lcd). The necessary Python packages can be installed for the user or in a virtual environment. After that a system service can be created to start the script on boot.
### Find the correct pins
Before running the script it's important you check the pins that are initialized in the first few lines of the script! Change them to the correct pins if necessary.
### Install packages for the user
Use the following command:
```console
$pip3 install-r requirements.txt
```
### Install in a virtual environment
To create virtual Python environments (in short venv) you first need to install `python3-venv`:
```console
$sudo apt install python3-venv
```
After that you can create a new virtual environment by using:
```
$ python3 -m venv <directory name>
```
where `directory name` is the name of the directory where the venv is stored in.
To activate it use:
```console
$source <directory name>/bin/activate
```
After that you can just install the packages normally:
```console
$pip3 install-r requirements.txt
```
### Create a system service
If you already created the system service in [the initial Raspberry setup](/setup/Setting-up-a-Raspberry-Pi-for-the-demo) you can overwrite this service or create a new one. In the following steps we will reuse it.
#### Creating a `start.sh`
Copy the following lines in a file called `start.sh` in the lcd directory:
```bash
#!/bin/bash
cd /home/pi/vws-spielwiese/scripts/lcd
# Uncomment and change the following line if you used an virtual environment!
# source venv/bin/activate
python3 display.py
```
To make that file executable run `chmod +x ./start.sh`.
