GOARCH=arm go build temper.go

temper.go

package main

import (
	"fmt"
	"golang.org/x/exp/io/i2c"
	"os"
	"strconv"
)

func main() {
	file, err := os.Open("/dev/temper0")
	if err != nil {
		fmt.Printf("failed to open thermometer: %s\n", err)
		return
	}
	defer file.Close()

	device, err := i2c.Open(&i2c.Devfs{Dev: "/dev/i2c-1"}, 0x67)
	if err != nil {
		fmt.Printf("can not open display: %s\n", err)
		return
	}
	defer device.Close()

	buf := []byte{0, 0, 0, 0}
	bytes, err := file.Read(buf)
	if err != nil || bytes != 4 {
		fmt.Println("failed to read input")
		return
	}

	x1, err := strconv.Atoi(string(buf))
	if err != nil {
		fmt.Printf("can not convert input: %s\n", err)
		return
	}

	temperature := float32(x1) * 125 / 32000
	str := fmt.Sprintf("%2.2f", temperature)
	fmt.Printf("temp: %s\n", str)

	device.WriteReg(0x76, []byte{str[0], str[1], str[3], str[4]})
	device.WriteReg(0x77, []byte{0x2})
}