Read from a serial port and extract JSON.

readSerial.go

package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"log"

	"github.com/tarm/serial"
)

func main() {
	c := &serial.Config{Name: "/dev/cu.usbserial-14120", Baud: 9600}
	ser, err := serial.OpenPort(c)
	if err != nil {
		log.Fatal(err)
	}

	scanner := bufio.NewScanner(ser)

	for scanner.Scan() {
		output := scanner.Bytes()
		var f interface{}
		err := json.Unmarshal(output, &f)
		if err != nil {
			fmt.Println("Trying again")
		} else {
			m := f.(map[string]interface{})
			fmt.Println(m["light"])
			fmt.Println(m["temperature"])
			fmt.Println(m["humidity"])
			for k, v := range m {
				switch vv := v.(type) {
				case string:
					fmt.Println(k, "is string", vv)
				case float64:
					fmt.Println(k, "is float64", vv)
				case []interface{}:
					fmt.Println(k, "is an array:")
					for i, u := range vv {
						fmt.Println(i, u)
					}
				default:
					fmt.Println(k, "is of a type I don't know how to handle")
				}
			}
		}
	}
}