Initial commit

Signed-off-by: Thomas Klaehn <tkl@blackfinn.de>
2025-10-01 09:38:42 +02:00
commit 5a170736d6
7 changed files with 363 additions and 0 deletions
--- a/main.go
+++ b/main.go
@@ -0,0 +1,165 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/simonvetter/modbus"
+
+	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
+)
+
+type mod_bus struct {
+	Protocol     string `json:"protocol"`
+	BaudRate     int    `json:"baud_rate"`
+	SlaveAddress int    `json:"slave_address"`
+	Host         string `json:"host"`
+	Port         int    `json:"port"`
+}
+
+type register struct {
+	Name     string  `json:"name"`
+	Type     string  `json:"type"`
+	Address  int     `json:"address"`
+	Quantity int     `json:"quantity"`
+	Factor   float32 `json:"factor"`
+	Unit     string  `json:"unit"`
+}
+
+type device struct {
+	Name      string     `json:"name"`
+	Type      string     `json:"type"`
+	Modbus    mod_bus    `json:"modbus"`
+	Registers []register `json:"registers"`
+}
+type config struct {
+	SampleRate    int      `json:"sample_rate"`
+	InfluxdbHost  string   `json:"influxdb_host"`
+	InfluxdbPort  int      `json:"influxdb_port"`
+	InfluxdbToken string   `json:"influxdb_token"`
+	Devices       []device `json:"devices"`
+}
+
+var (
+	logger       log.Logger = *log.Default()
+	config_path  string
+	config_cache config
+)
+
+func init() {
+	logger.SetFlags(log.Llongfile | log.Ltime)
+}
+
+func read_config() {
+	data, err := os.ReadFile(config_path)
+	if err != nil {
+		logger.Printf("Unable to read %s", config_path)
+		return
+	}
+	err = json.Unmarshal(data, &config_cache)
+	if err != nil {
+		logger.Print("Unable to evaluate config data")
+		return
+	}
+}
+
+func main() {
+	flag.StringVar(&config_path, "c", "../config/config.json", "Specify path to find the config file. Default is ../config/config.json")
+	flag.Parse()
+	read_config()
+
+	type remote struct {
+		client    *modbus.ModbusClient
+		registers []register
+		name      string
+	}
+	var err error
+	var remotes []remote
+	var client *modbus.ModbusClient
+
+	// setup influx connection
+	influxdb_url := "http://" + config_cache.InfluxdbHost + ":" + strconv.Itoa(config_cache.InfluxdbPort)
+	db_client := influxdb2.NewClient(influxdb_url, config_cache.InfluxdbToken)
+	defer db_client.Close()
+	ctx := context.Background()
+	write_api := db_client.WriteAPIBlocking("tkl", "home")
+
+	for _, v := range config_cache.Devices {
+		if v.Modbus.Protocol == "tcp" {
+			url := v.Modbus.Protocol + "://" + v.Modbus.Host + ":" + strconv.Itoa(v.Modbus.Port)
+			client, err = modbus.NewClient(&modbus.ClientConfiguration{URL: url})
+			if err != nil {
+				logger.Printf("failed to create modbus client: %v\n", err)
+				continue
+			}
+			client.SetUnitId(0x55)
+			err = client.Open()
+			if err != nil {
+				logger.Printf("failed to connect: %v\n", err)
+				continue
+			}
+
+			var tmp remote
+			tmp.client = client
+			tmp.registers = v.Registers
+			tmp.name = v.Name
+			remotes = append(remotes, tmp)
+		}
+	}
+
+	for { // ever
+		for _, remote := range remotes {
+			point := influxdb2.NewPointWithMeasurement(remote.name)
+			for _, reg := range remote.registers {
+				res, err := remote.client.ReadRegisters(uint16(reg.Address), uint16(reg.Quantity), modbus.HOLDING_REGISTER)
+				if err != nil {
+					logger.Printf("failed to read: %v\n", err)
+					error_strings := []string{
+						"connection reset by peer",
+						"broken pipe",
+					}
+					for _, error_string := range error_strings {
+						if strings.Contains(err.Error(), error_string) {
+							logger.Print("trying to restart modbus client")
+							remote.client.Close()
+							err = remote.client.Open()
+							if err != nil {
+								logger.Printf("failed to restart: %v\n", err)
+								os.Exit(1)
+							}
+						}
+					}
+					continue
+				}
+				var tmp int32
+				switch reg.Quantity {
+				case 1:
+					tmp = int32(res[0])
+				case 2:
+					tmp = ((int32(res[0]) << 16) | int32(res[1]))
+				default:
+					logger.Printf("Unsupported quantity of registers (%d)", reg.Quantity)
+					continue
+				}
+				result := float32(tmp) * reg.Factor
+				point.AddField(reg.Name, result)
+			}
+			point.SetTime(time.Now())
+			err := write_api.WritePoint(ctx, point)
+			if err != nil {
+				logger.Print(err)
+			}
+			err = write_api.Flush(ctx)
+			if err != nil {
+				logger.Print(err)
+			}
+		}
+		time.Sleep(time.Duration(config_cache.SampleRate * 1000000000))
+	}
+}