MQTT -> DALI bridge for happyswing on Raspberry Pi

Raspberry Pi setup and prerequisites

Flash Raspberry Pi OS Lite to SD card, using the Raspberry Pi Imager https://www.raspberrypi.org/software/
On the SD card, create a file named ssh in the boot partition - this will enable SSH on the Raspberry Pi for headless setup
On the SD card, create a file named userconf in the boot partition with the following content:
```
pi:encyptedpassword
```
where pi is the username (feel free to use any username) and encryptedpassword is the output of the following command:
```
echo 'mypassword' | openssl passwd -6 -stdin
```
Bonus tip: copy your public SSH key as one line in ~/.ssh/authorized_keys to allow passwordless login (also helpful for VS Code remote SSH).
ideally, configure the DHCP server to assign a static IP address to the Raspberry Pi based on its MAC address. In our case we use 192.168.1.252.
configure udev to allow access to the USB DALI bus gateway. Download the file https://github.com/sde1000/python-dali/blob/master/examples/50-dali-hid.rules and copy it to `/etc/udev/rules.d``. Reboot.
Connect the USB DALI bus gateway to the Raspberry Pi. When running sudo dmesg -T you should see that the DALI device was connected.

Install required packages:

sudo apt update
sudo apt-get install git python3-venv

Install software enviroment

To allow GitHub operations from the Raspberry Pi you want to use SSH agent forwarding. On your local machine, run ssh-add to add your SSH key to the agent. Then connect to the Raspberry Pi using ssh -A pi@192.168.1.252.

Clone the GithHub repository and bootstrap it:

cd
git clone git@github.com:jodok/happyswing-dali.git --recurse-submodules
cd happyswing-dali
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

Development

The used library, https://github.com/sde1000/python-dali doesn't have a recent release, that's why it is included as a git submodule. To update it, run:
```
git submodule update --remote
```
It turned out to be very helpful to develop with the VSCode remote SSH extension. It's easy to connect if you already added your ssh keys as described above.

Examples

Simple example that lets the DALI devices blink a few times: https://github.com/sde1000/python-dali/blob/master/examples/async-flash.py
Next steps: Instead of sending a broadcast like this:
```
await dev.send(RecallMaxLevel(Broadcast()))
```
use this command to send the dim level for device a1:
```
await driver.send(DAPC(GearShort(1), 120))
```
where 120 is the dim level. 255 is the maximum dim level for 100%. You can use any value down to the minimal physical dim-level. The physial minimum is device specific (e.g. 1% = 86).

Auto start after boot

We use systemd to autostart the happyswing service after boot.

First the service needs to be put in the right directory.

  sudo cp happyswing.service  /lib/systemd/system/happyswing.service

After that the service can be enabled with

  sudo systemctl daemon-reload
  sudo systemctl enable happyswing
  sudo systemctl start happyswing

Now the service runs when the Raspberry Pi started.

To stop the service run

  sudo systemctl stop happyswing

To look at the logs of the service use

  journalctl -u happyswing

MQTT Broker

A MQTT broker can be run locally. The following description will setup and configure the Mosquitto MQTT Broker.

To install run:

  sudo apt install mosquitto

To start the broker after booting use

  sudo systemctl enable mosquitto

The broker is configured to listen on the same port as mqtt.happyswing.at and use the same username and password to easily switch.

To configure credentials run

  sudo mosquitto_passwd -c /etc/mosquitto/credentials happyswing

Next, the following configurations are added to the file /etc/mosquitto/conf.d/local.conf

  listener 8883
  allow_anonymous false
  password_file /etc/mosquitto/credentials

If the local MQTT broker is used, the Happyswing App needs to be started like the following

  python main.py --mqtt_address localhost  --ca_certs ""

This needs also to be changes in the happyswing.service file