first commit

lywsd03mmc-exporter.go

@@ -0,0 +1,214 @@
+// lywsd03mmc-exporter - a Prometheus exporter for the LYWSD03MMC BLE thermometer
+
+// Copyright (C) 2020 Leah Neukirchen <leah@vuxu.org>
+// Licensed under the terms of the MIT license, see LICENSE.
+
+package main
+
+import (
+	"context"
+	"encoding/binary"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-ble/ble"
+	"github.com/go-ble/ble/examples/lib/dev"
+)
+
+
+// Reading represents a Temperature|Humidity readings
+type Reading struct {
+	Temperature float64
+	Humidity    float64
+}
+
+const Sensor = "LYWSD03MMC"
+const TelinkVendorPrefix = "a4:c1:38"
+
+var EnvironmentalSensingUUID = ble.UUID16(0x181a)
+var XiaomiIncUUID = ble.UUID16(0xfe95)
+
+const ExpiryAtc = 2.5 * 10 * time.Second
+const ExpiryStock = 2.5 * 10 * time.Minute
+const ExpiryConn = 2.5 * 10 * time.Second
+
+var expirers = make(map[string]*time.Timer)
+var expirersLock sync.Mutex
+
+
+
+var (
+	configFile = flag.String("config_file", "config.ini", "Config file location")
+)
+
+var config, ERR = NewConfig(*configFile)
+
+func bump(mac string, expiry time.Duration) {
+	expirersLock.Lock()
+	if t, ok := expirers[mac]; ok {
+		t.Reset(expiry)
+	} else {
+		expirers[mac] = time.AfterFunc(expiry, func() {
+			fmt.Printf("expiring %s\n", mac)
+			expirersLock.Lock()
+			delete(expirers, mac)
+			expirersLock.Unlock()
+		})
+	}
+	expirersLock.Unlock()
+}
+
+func macWithColons(mac string) string {
+	return strings.ToUpper(fmt.Sprintf("%s:%s:%s:%s:%s:%s",
+		mac[0:2],
+		mac[2:4],
+		mac[4:6],
+		mac[6:8],
+		mac[8:10],
+		mac[10:12]))
+}
+
+func macWithoutColons(mac string) string {
+	return strings.ReplaceAll(strings.ToUpper(mac), ":", "")
+}
+
+func decodeSign(i uint16) int {
+	if i < 32768 {
+		return int(i)
+	} else {
+		return int(i) - 65536
+	}
+}
+
+func registerData(data []byte, frameMac string, rssi int) {
+	if len(data) != 13 {
+		return
+	}
+
+	mac := fmt.Sprintf("%X", data[0:6])
+
+	if mac != frameMac {
+		return
+	}
+
+	temp := float64(decodeSign(binary.BigEndian.Uint16(data[6:8]))) / 10.0
+	hum := float64(data[8])
+	batp := float64(data[9])
+	batv := float64(binary.BigEndian.Uint16(data[10:12])) / 1000.0
+	//frame := float64(data[12])
+
+	bump(mac, ExpiryAtc)
+
+	logTemperature(mac, temp)
+	logHumidity(mac, hum)
+	logBatteryPercent(mac, batp)
+	logVoltage(mac, batv)
+	logRssi(mac, rssi)
+	var r = Reading{temp, hum}
+	config.MQTT.Publish(mac,&r)
+}
+
+func advHandler(a ble.Advertisement) {
+	mac := strings.ReplaceAll(strings.ToUpper(a.Addr().String()), ":", "")
+
+	for _, sd := range a.ServiceData() {
+		if sd.UUID.Equal(EnvironmentalSensingUUID) {
+			registerData(sd.Data, mac, a.RSSI())
+		}
+	}
+}
+
+
+func logTemperature(mac string, temp float64) {
+	log.Printf("%s thermometer_temperature_celsius %.1f\n", mac, temp)
+}
+
+func logHumidity(mac string, hum float64) {
+	log.Printf("%s thermometer_humidity_ratio %.0f\n", mac, hum)
+}
+
+func logVoltage(mac string, batv float64) {
+	log.Printf("%s thermometer_battery_volts %.3f\n", mac, batv)
+}
+
+func logBatteryPercent(mac string, batp float64) {
+	log.Printf("%s thermometer_battery_ratio %.0f\n", mac, batp)
+}
+
+func logRssi(mac string, rssi int) {
+	log.Printf("%s thermometer_rssi %d\n", mac, rssi)
+}
+
+func decodeAtcTemp(mac string) func(req []byte) {
+	return func(req []byte) {
+		temp := float64(decodeSign(binary.LittleEndian.Uint16(req[0:2]))) / 10.0
+		bump(mac, ExpiryConn)
+		logTemperature(mac, temp)
+	}
+}
+
+func decodeAtcHumidity(mac string) func(req []byte) {
+	return func(req []byte) {
+		hum := float64(binary.LittleEndian.Uint16(req[0:2])) / 100.0
+		bump(mac, ExpiryConn)
+		logHumidity(mac, hum)
+	}
+}
+
+func decodeAtcBattery(mac string) func(req []byte) {
+	return func(req []byte) {
+		batp := float64(req[0])
+		bump(mac, ExpiryConn)
+		logBatteryPercent(mac, batp)
+	}
+}
+
+// ToString converts a Reading to a string
+func (r *Reading) String() string {
+	return fmt.Sprintf("Temperature: %.04f; Humidity: %.04f", r.Temperature, r.Humidity)
+}
+
+
+func main() {
+	flag.Parse()
+	//config, err := NewConfig(*configFile)
+	//if err != nil {
+	//	log.Fatal("Unable to parse configuration")
+	//}
+
+	log.Printf("MQTT broker: %s", config.MQTT.Server())
+	if err := config.MQTT.Connect("xiaomi"); err != nil {
+		log.Print("[main] Unable to connect to MQTT broker")
+	}
+
+
+	deviceID := flag.Int("i", 0, "use device hci`N`")
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr,
+			"Usage: %s [FLAGS...] \n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+
+	device, err := dev.NewDevice("default", ble.OptDeviceID(*deviceID))
+	if err != nil {
+		log.Fatal("oops: ", err)
+	}
+
+	ble.SetDefaultDevice(device)
+
+	ctx := ble.WithSigHandler(context.Background(), nil)
+
+	telinkVendorFilter := func(a ble.Advertisement) bool {
+		return strings.HasPrefix(a.Addr().String(), TelinkVendorPrefix)
+	}
+	err = ble.Scan(ctx, true, advHandler, telinkVendorFilter)
+	if err != nil {
+		log.Fatal("oops: %s", err)
+	}
+}