bt-sensors-plugin-sk/sensor_classes/GoveeH510x.js

Bluetooth Sensors for Signalk -- support for Victron devices, RuuviTag, Xiaomi, ATC and Inkbird, Ultrasonic wind meters, Mopeka tank readers, Renogy Battery and Solar Controllers, Aranet4 environment sensors, SwitchBot temp and humidity sensors, Kilovault

const BTSensor = require("../BTSensor");
function decodeTempHumid(tempHumidBytes) {
    // Convert the bytes to a 24-bit integer
    const baseNum = (tempHumidBytes[0] << 16) + (tempHumidBytes[1] << 8) + tempHumidBytes[2];
  
    // Check if the temperature is negative
    const isNegative = (baseNum & 0x800000) !== 0;
  
    // Extract the temperature and humidity values
    const tempAsInt = baseNum & 0x7FFFFF;
    const tempAsFloat = (tempAsInt / 1000) / 10.0;
    const humid = (tempAsInt % 1000) / 10.0;
  
    // Apply the negative sign if necessary
    if (isNegative) {
      return {t:-tempAsFloat, h: humid};
    } else {
      return {t: tempAsFloat, h: humid};
    }
  }
class GoveeH510x extends BTSensor{

    static async  identify(device){
        const regex = /^GVH510[0-9]_[a-f,A-F,0-9]{4}$/
        const name = await this.getDeviceProp(device,"Name")
        const uuids = await this.getDeviceProp(device,'UUIDs')

        if (name && name.match(regex) && 
            uuids && uuids.length > 0 && 
            uuids[0] == '0000ec88-0000-1000-8000-00805f9b34fb')
            return this
        else
            return null
        
    }

    async init(){
        await super.init()
        this.initMetadata()
    }
    initMetadata(){
        this.addMetadatum('temp','K', 'temperature')
        this.addMetadatum('battery','ratio', 'battery strength')
        this.addMetadatum('humidity','ratio', 'humidity')
    }

    emitValuesFrom(buffer){
        const th = decodeTempHumid(buffer.subarray(2,5))
        this.emit("temp", parseFloat((273.15+th.t).toFixed(2))) ;
        this.emit("humidity", th.h/100 )
        this.emit('battery', buffer[5]/100)
    }

    getManufacturer(){
        return "Govee"
    }
    async propertiesChanged(props){
        super.propertiesChanged(props)    
        if (!props.hasOwnProperty("ManufacturerData")) return

        const buffer = this.getManufacturerData(0x0001)
        if (buffer) {
            this.emitValuesFrom(buffer)
        }      
   }                         
}
module.exports=GoveeH510x