ON AIR light

Because it's about time people stopped barging into your room when you're on Zoom

Setup

Prerequistes: A MacOS computer with up to date OS.

First, set up the monitoring agent, which will send MQTT messages when your computer turns the camera on and off.

If you don't already have it, install Homebrew.
If you don't already have Mosquitto, use Homebrew to install it:
```
brew install mosquitto
```

Check out this repo

git clone git@github.com:triblondon/on-air-lights.git
cd on-air-lights

Make a copy of config-dist.sh called config.sh:
```
cp config-dist.sh config.sh
```

Open the new config.sh file in your favourite text editor and fill in the required values, eg:

mqtt_server=foo.cloudmqtt.com
mqtt_port=12345
mqtt_user=jane
mqtt_password=password
mqtt_topic=on-air-sign

Now, set up the hardware:

Make or acquire an ON-AIR light. This could be a neon-y sign like mine or just any old light that turns on when you send power to it.
Install the ESPHome CLI
Plug an ESP8266 or ESP32 microcontroller into a spare USB port on your computer. I used the tiny ESP-01S paired with the purpose-made relay module which can often be purchased together (eg. Amazon).
Make a copy of secrets-dist.yaml called secrets.yaml:
```
cd esphome
cp secrets-dist.yamls secrets.yaml
```

Open the new secrets.yaml file in your favourite text editor and fill in the required values, eg:

wifi_ssid: "Foo"
wifi_password: "password"
mqtt_server: "foo.cloudmqtt.com"
mqtt_port: 12345
mqtt_username: "jane"
mqtt_password: "password"

Install the ESPHome configuration onto the microcontroller:
```
esphome run esphome/on-air-light.yaml
```
Unplug the microcontroller from the computer and connect it to a relay that is controlling your ON AIR light. Connect the relay to GPIO0 (which is the correct pin for the ESP-01S Relay module)

Great! Now when your computer turns the camera on, your sign will light up.