Develop Homebridge Hardware Driver

Currently, only some ‘Powered by Tuya’ (PBT) product categories can be integrated with Homebridge. Based on Tuya’s standard instruction set documents, you can develop your desired product driver of the Tuya Homebridge plugin, so as to control more PTB devices through Homebridge.

Prerequisites

• You have completed configurations on the Tuya IoT Platform.
• You have run the Tuya Homebridge plugin.

Step 1: Get device information

Even if some PBT devices are not connected to Homebridge, we can still run the Tuya Homebridge plugin to get the device status information in the log. For example, the classification of the device in the Tuya product system, that is, the catagory.

1. Enable the debug mode and view the debug log.

   Note: For more information about how to view logs in debug mode, see How to Get Logs.

2. You can get the log of device information by your device name.

   Note: Start with active_time and end with uuid. For example, if you search for Living room switch from the log, you will get the information of the device. The sample code is as follows.

   

   {
         "active_time": 1623229189,
         "biz_type": 18,
         "category": "cz",
         "create_time": 1560491945,
         "icon": "smart/product_icon/cz.png",
         "id": "xxxxxxxxxxxxxxx",
         "ip": "xxxxxxxxxxxxxxx",
         "lat": "30.30286857361191",
         "local_key": "xxxxxxxx",
         "lon": "120.0639743842656",
         "model": "",
         "name": "Living room switch",
         "online": false,
         "owner_id": "34794909",
         "product_id": "yfemiswbgjhddhcf",
         "product_name": "Switch Product",
         "status": [
           {
             "code": "switch",
             "value": false
           },
           {
             "code": "countdown_1",
             "value": 0
           },
           {
             "code": "cur_current",
             "value": 0
           },
           {
             "code": "cur_power",
             "value": 0
           },
           {
             "code": "cur_voltage",
             "value": 2343
           }
         ],
         "sub": false,
         "time_zone": "+08:00",
         "uid": "ay1622097934070h5Mpi",
         "update_time": 1625101929,
         "uuid": "65015854bcddc21a9073"
   }
   

Step 2: Find the category

After you get the category information, you can proceed to get the parameter descriptions of the standard instruction set and standard status set based on the category (for example, cz) in the documentation center of the Tuya Developer Platform, so as to prepare for subsequent driver development.

1. Get the parameter descriptions of the standard instruction set and status set of the category.

   1. According to the "category": "cz" in the log, the category of the device Living room switch in this example is defined as cz by Tuya.

   2. In the search bar on the left side of the Tuya Developer Documentation Center, search for the cloud instruction set and status set for the specified category value, such as cz.

      

2. Get the Homebirdge service type of the category.
   Find a similar service type in the Homebridge API to facilitate subsequent driver development. In this example, the product is similar to the outlet, so we choose Outlet.

   

Step 3: Develop the driver

1. According to the selected Outlet service type, create an outlet_accessory.js file in the tuya-homebridge project.

   

2. Add a category.
   To support cz devices, we must add cz to the addAccessory() method in the index.js file. The code is as follows.

   

   case 'cz':
       deviceAccessory = new OutletAccessory(this, homebridgeAccessory, device);
       this.accessories.set(uuid, deviceAccessory.homebridgeAccessory);
       this.deviceAccessories.set(uuid, deviceAccessory);
       break;
   

3. Develop the plugin.

   Develop the plugin in the outlet_accessory.js file. See outlet_accessory.js for the sample code.

   1. Set Characteristics, and set the Get and Set callbacks of this attribute.

      Note: Characteristics is the service attribute corresponding to the Outlet type in the HomeBridge API. The Characteristics is On.

      • get: Return the device status to Homebridge, and display it on the Home app.

      • set: When the on and off actions are triggered on the Home app, you can send the instructions to the device through this callback.

         if (this.isRefresh) {
            service
              .getCharacteristic(Characteristic.On)
              .updateValue(value);
          } else {
            this.getAccessoryCharacteristic(service, Characteristic.On);
          }
        

        getAccessoryCharacteristic(service, name) {
            //set  Accessory service Characteristic
            service.getCharacteristic(name)
              .on('get', callback => {
                if (this.hasValidCache()) {
                  callback(null, this.getCachedState(service.displayName));
                }
              })
              .on('set', (value, callback) => {
                var param = this.getSendParam(service.displayName, value)
                this.platform.tuyaOpenApi.sendCommand(this.deviceId, param).then(() => {
                  this.setCachedState(service.displayName, value);
                  callback();
                }).catch((error) => {
                  this.log.error('[SET][%s] Characteristic.Brightness Error: %s', this.homebridgeAccessory.displayName, error);
                  this.invalidateCache();
                  callback(error);
                });
              });
          }
        

   2. In the get callback, the value false of the DP code switch is called back to the Homebridge Service. In the set callback, switch is sent to the device as the DP code, together with the specified value.

      "status": [
              {
                "code": "switch",
                "value": false
              },
              {
                "code": "countdown_1",
                "value": 0
              },
            ]
      
      

      

      You can get the relationship between code and value from the standard instruction set and standard status set.

      

      The following shows instructions to turn on the light.

      {
         "code": "switch",
         "value": true
      }
      

Step 4: Control devices

After you add a category, you can run the Tuya Homebridge plugin again. After you bridge to HomeKit, you can control the PBT devices on HomeKit.

• Run the plugin
• Bridge to HomeKit
• Control devices on the Home app

Device registration logic

When you start the plugin, the entry file index.js will call TuyaSHOpenAPI().getDevices() to get the devices under the current associated app account. After getting the device, it will traverse and call this.addAccessory(device); to create an Accessory instance and then register it in PlatformAccessories.

The creation of Accessory and Service is implemented in base_accessory.js. You do not need to develop them separately.

// Accessory
    if (this.homebridgeAccessory) {
      this.homebridgeAccessory.controller = this;
      if (!this.homebridgeAccessory.context.deviceId) {
        this.homebridgeAccessory.context.deviceId = this.deviceConfig.id;
      }
      
      this.log.log(`Existing Accessory found ${homebridgeAccessory.displayName}  ${homebridgeAccessory.context.deviceId} ${homebridgeAccessory.UUID}`);
      this.homebridgeAccessory.displayName = this.deviceConfig.name;
    }
    else {
      // Create new Accessory
      this.log.log(`Creating New Accessory ${this.deviceConfig.id}`);
      this.homebridgeAccessory = new PlatformAccessory(
        this.deviceConfig.name,
        UUIDGen.generate(this.deviceConfig.id),
        categoryType);
      this.homebridgeAccessory.context.deviceId = this.deviceConfig.id;
      this.homebridgeAccessory.controller = this;
      this.platform.registerPlatformAccessory(this.homebridgeAccessory);
    }
	
    // Service
    if (this.subServices.length == 0) {
      // Service
      this.service = this.homebridgeAccessory.getService(this.serviceType);
      if (this.service) {
        this.service.setCharacteristic(Characteristic.Name, this.deviceConfig.name);
      }
      else {
        // add new service
        this.service = this.homebridgeAccessory.addService(this.serviceType, this.deviceConfig.name);
      }
    } else {
      // SubService
      for (const subService of this.subServices) {
        var service = this.homebridgeAccessory.getService(subService);
        if (service) {
          service.setCharacteristic(Characteristic.Name, subService);
        } else {
          // add new subService
          this.homebridgeAccessory.addService(this.serviceType, subService, subService);
        }
      }
    }