sensor: added driver for MCP9808 temperature sensor

samples/mcp9808.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"time"
+
+	"github.com/kidoman/embd"
+	_ "github.com/kidoman/embd/host/rpi"
+	"github.com/kidoman/embd/sensor/mcp9808"
+	"github.com/stianeikeland/go-rpio"
+)
+
+func main() {
+	if err := embd.InitI2C(); err != nil {
+		panic(err)
+	}
+	defer embd.CloseI2C()
+
+	bus := embd.NewI2CBus(1)
+
+	therm := mcp9808.New(bus)
+
+	if id, err := therm.ManufacturerID(); err == nil {
+		fmt.Printf("Manufacturer ID: 0x%x\n", id)
+	}
+
+	if devID, rev, err := therm.DeviceID(); err == nil {
+		fmt.Printf("Device ID: 0x%x rev. 0x%x\n", devID, rev)
+	}
+
+	therm.SetShutdownMode(false)
+
+	//therm.SetWindowTempLock(false)
+	// therm.SetCriticalTempLock(false)
+
+	config, err := therm.WriteConfig()
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("New Config: %b\n", config)
+	therm.SetAlertControl(true)
+	//therm.SetInterruptClear(true)
+	//therm.SetAlertStatus(true)
+	//therm.SetAlertSelect(false)
+	//therm.SetAlertPolarity(true)
+	//therm.SetAlertMode(true)
+	config, err = therm.WriteConfig()
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("New Config: %b\n", config)
+
+	if err := therm.SetWindowTempUpper(TempFToC(80)); err != nil {
+		panic(err)
+	}
+
+	temp, err := therm.AmbientTemp()
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("Temp is %f\n", TempCToF(temp.CelsiusDeg))
+
+	if err := embd.InitGPIO(); err != nil {
+		panic(err)
+	}
+	if err := rpio.Open(); err != nil {
+		log.Fatalf("Error: %v\n", err)
+	}
+	defer rpio.Close()
+	defer embd.CloseGPIO()
+
+	alert := rpio.Pin(4)
+	alert.Input()
+	alert.PullDown()
+
+	timer := time.Tick(time.Duration(5) * time.Second)
+
+	cancel := make(chan bool)
+	go func() {
+		reader := bufio.NewReader(os.Stdin)
+		reader.ReadString('\n')
+		cancel <- true
+	}()
+	for {
+		select {
+		case <-timer:
+			temp, err := therm.AmbientTemp()
+			if err == nil {
+				fmt.Printf("Ambient temp is: %f\n", TempCToF(temp.CelsiusDeg))
+			}
+			status := alert.Read()
+			fmt.Printf("Status: %d\n\n", status)
+			if status == rpio.High {
+				fmt.Println("Alert temp has been reached.")
+				return
+			}
+		case <-cancel:
+			return
+		}
+	}
+}
+
+func TempCToF(tempC float64) float64 {
+	return tempC*9/5 + 32
+}
+
+func TempFToC(tempF float64) float64 {
+	return (tempF - 32) * 5 / 9
+}