Example work

protypes/modbus_logger/go.sum

@@ -0,0 +1,14 @@
+github.com/goburrow/modbus v0.1.0 h1:DejRZY73nEM6+bt5JSP6IsFolJ9dVcqxsYbpLbeW/ro=
+github.com/goburrow/modbus v0.1.0/go.mod h1:Kx552D5rLIS8E7TyUwQ/UdHEqvX5T8tyiGBTlzMcZBg=
+github.com/goburrow/serial v0.1.0 h1:v2T1SQa/dlUqQiYIT8+Cu7YolfqAi3K96UmhwYyuSrA=
+github.com/goburrow/serial v0.1.0/go.mod h1:sAiqG0nRVswsm1C97xsttiYCzSLBmUZ/VSlVLZJ8haA=
+github.com/jonboulle/clockwork v0.4.0 h1:p4Cf1aMWXnXAUh8lVfewRBx1zaTSYKrKMF2g3ST4RZ4=
+github.com/jonboulle/clockwork v0.4.0/go.mod h1:xgRqUGwRcjKCO1vbZUEtSLrqKoPSsUpK7fnezOII0kc=
+github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07 h1:UyzmZLoiDWMRywV4DUYb9Fbt8uiOSooupjTq10vpvnU=
+github.com/tarm/serial v0.0.0-20180830185346-98f6abe2eb07/go.mod h1:kDXzergiv9cbyO7IOYJZWg1U88JhDg3PB6klq9Hg2pA=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+periph.io/x/conn/v3 v3.7.1 h1:tMjNv3WO8jEz/ePuXl7y++2zYi8LsQ5otbmqGKy3Myg=
+periph.io/x/conn/v3 v3.7.1/go.mod h1:c+HCVjkzbf09XzcqZu/t+U8Ss/2QuJj0jgRF6Nye838=
+periph.io/x/host/v3 v3.8.2 h1:ayKUDzgUCN0g8+/xM9GTkWaOBhSLVcVHGTfjAOi8OsQ=
+periph.io/x/host/v3 v3.8.2/go.mod h1:yFL76AesNHR68PboofSWYaQTKmvPXsQH2Apvp/ls/K4=

protypes/modbus_logger/modbus_logger.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"encoding/binary"
+	"fmt"
+	"log"
+	"math"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/goburrow/modbus"
+	"github.com/tarm/serial"
+	"periph.io/x/conn/v3/gpio"
+	"periph.io/x/conn/v3/gpio/gpioreg"
+	"periph.io/x/host/v3"
+)
+
+const (
+	serialPort = "/dev/ttyAMA0"
+	baudRate   = 9600
+	dataBits   = 8
+	stopBits   = 1
+	parity     = "N"
+	slaveID    = 101
+	deRePin    = "GPIO4"
+)
+
+var registers = []struct {
+	regaddr uint16
+	regtype uint8
+}{
+	{1, 2},
+	{3, 1},
+	{5, 0},
+	// Add more registers as needed
+}
+
+func main() {
+	// Initialize GPIO
+	if _, err := host.Init(); err != nil {
+		log.Fatal(err)
+	}
+
+	// Set up DE/RE pin
+	deRe := gpioreg.ByName(deRePin)
+	if deRe == nil {
+		log.Fatal("Failed to find DE/RE pin")
+	}
+
+	// Configure serial port
+	config := &serial.Config{
+		Name: serialPort,
+		Baud: baudRate,
+		//DataBits: dataBits,
+		StopBits: stopBits,
+		//Parity:   parity,
+	}
+
+	// Create Modbus RTU client
+	handler := modbus.NewRTUClientHandler(config.Name)
+	handler.BaudRate = config.Baud
+	//handler.DataBits = config.DataBits
+	//handler.StopBits = config.StopBits
+	//handler.Parity = config.Parity
+	handler.SlaveId = slaveID
+	handler.Timeout = 5 * time.Second
+
+	err := handler.Connect()
+	if err != nil {
+		log.Fatal("Failed to connect:", err)
+	}
+	defer handler.Close()
+
+	client := modbus.NewClient(handler)
+
+	for {
+		filename := getFilename()
+		file, err := os.OpenFile(filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+		if err != nil {
+			log.Println("Error opening file:", err)
+			continue
+		}
+
+		// Write CSV header if file is empty
+		fileInfo, _ := file.Stat()
+		if fileInfo.Size() == 0 {
+			header := "Date Time"
+			for _, reg := range registers {
+				header += fmt.Sprintf(",@%d", reg.regaddr)
+			}
+			file.WriteString(header + "\n")
+		}
+
+		// Log current date and time
+		timestamp := time.Now().Format("2006-01-02 15:04:05")
+		line := timestamp
+
+		for _, reg := range registers {
+			deRe.Out(gpio.High)
+			results, err := client.ReadHoldingRegisters(reg.regaddr-1, 2)
+			deRe.Out(gpio.Low)
+
+			if err != nil {
+				log.Printf("Error reading register %d: %v", reg.regaddr, err)
+				line += ",ERROR"
+				continue
+			}
+
+			switch reg.regtype {
+			case 2: // Float
+				value := math.Float32frombits(binary.BigEndian.Uint32(results))
+				line += fmt.Sprintf(",%.2f", value)
+			case 1: // Uint16
+				value := binary.BigEndian.Uint16(results)
+				line += fmt.Sprintf(",%d", value)
+			case 0: // Int32
+				value := int32(binary.BigEndian.Uint32(results))
+				line += fmt.Sprintf(",%d", value)
+			default:
+				line += ",UNKNOWN"
+			}
+		}
+
+		file.WriteString(line + "\n")
+		file.Close()
+
+		log.Printf("Data written to %s", filename)
+		time.Sleep(1 * time.Second)
+	}
+}
+
+func getFilename() string {
+	now := time.Now()
+	return filepath.Join("data", fmt.Sprintf("pm8k_%s.csv", now.Format("20060102")))
+}