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Homebridge + Humidity Sensor

In this sample, we will use HomeBridge to integrate our device with Apple HomeKit. As an example, we will expose a humidity sensor to HomeKit.

HomeBridge allows you to integrate with smart home devices that do not natively support HomeKit. Using the HomeBridge MQTTThing plugin, you can integrate your MQTT Things with HomeKit. The DeviceScript Gateway can be configured to route cloud messages to a MQTT server which can then be used by HomeBridge.

MQTT server configuration​

You will need the URL, port and optionaly username, password to configure the gateway.

Device Gateway configuration​

  • Clone or create a DeviceScript Gateway (by starting a GitHub Codespace for example)
  • Configure it to route the messages to the MQTT server
  • Start the development server. If you are using GitHub Codespaces, make sure to change the visibility of the port to Public in the Ports pane.
  • Copy the connection string that is printed in the terminal output and enter it in the DeviceScript Gateway pane in Visual Studio Code. You should get a confirmation that the gateway is connected.

HomeBridge configuration​

  • Install HomeBridge
  • Open the plugins pane and install the HomeBridge MQTTThing plugin plugin
  • Click on SETTINGS for the MQTTThing plugin and add a Humidity Sensor accessory
  • Configure the MQTT settings to connect to the MQTT server
  • Scroll down to the MQTT topics and set the get Humidity topic to humidity

Programming with simulators​

We can start programming with devicescript by using the simulator. The simulator allows you to test your code without having to deploy it to a physical device.

  • Create a new DeviceScript project using the DeviceScript: New Project command
  • Open main.ts and add the following code and click the Run icon on the file menu.
import { Humidity } from "@devicescript/core"
import { throttleTime } from "@devicescript/observables"

const sensor = new Humidity()
sensor.reading.pipe(throttleTime(5000)).subscribe(humidity => {
    console.data({ humidity })
})

Once the simulator is running and you start the humidity sensor simulator, you should see the humidity readings in the console.

  • Open the DeviceScript Gateway pane
  • Click on the + near devices to register the simulator

Update the program to publish the humidity readings to the cloud.

import { Humidity } from "@devicescript/core"
import { throttleTime } from "@devicescript/observables"
import { publishMessage } from "@devicescript/cloud"

const sensor = new Humidity()
sensor.reading.pipe(throttleTime(5000)).subscribe(async humidity => {
    console.data({ humidity })
    await publishMessage("/humidity", { humidity })
})
tip

Notice that the topic starts with /. By default DeviceScript routes topics to devs/{deviceid}/from/{topic}. Starting the topic with / disables this mode.

  • open HomeBridge and you should see the humidity being updated from the values on the sensor. Try to move the slider on the humidity sensor simulator to verify that the values are updated.

Programming hardware​

  • Click the plug icon and connect your device
  • Click on the magic wand icon on the file menu and select your hardware device. Then add the code to connect to the startSHTC3.
import { Humidity } from "@devicescript/core"
import { throttleTime } from "@devicescript/observables"
import { publishMessage } from "@devicescript/cloud"
import { startSHTC3 } from "@devicescript/drivers"

const { humidity: sensor } = await startSHTC3()

sensor.reading.pipe(throttleTime(5000)).subscribe(async humidity => {
    console.data({ humidity })
    await publishMessage("/humidity", { humidity })
})
  • Click the play button to deploy the script to your board and test it.

Managing the device with the Gateway​

The last step is to upload the script to the gateway and assign this script to the device. The gateway will automatically deploy the script to the device.

In the Device Gateway view,

  • Click + next to script and add your script
  • Click script icon near the device and assign the script you've just uploaded

Next steps​

  • If you want to continue iterating locally, make sure to clear the script assigned to your device (the extension will remind).
  • If you upload a new version of the script, make sure to update the assigned script on the device too.