app.go

package main

import (
	// "os"
	"fmt"
	"github.com/stianeikeland/go-rpio"
	"log"
	"net/http"
	// "sync"
	"time"
	// "sync/atomic"
)

const (
	LOCK_TIME time.Duration = 1 * time.Second
)

type Doorbot struct {
	pin rpio.Pin
	// mutex sync.Mutex turns out the pin logic has its own locks
}

type DoorbotHandler struct {
	bot Doorbot
}

func NewDoorbot(pin_no int) *Doorbot {
	pin := rpio.Pin(pin_no)
	pin.Output()
	return &Doorbot{
		pin: pin,
		// mutex: sync.Mutex{},
	}
}

func (d *Doorbot) Unlock() {
	d.pin.High()
	time.Sleep(LOCK_TIME)
	d.pin.Low()
}

func (d *Doorbot) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	// d.mutex.Lock()
	d.Unlock()
	// d.mutex.Unlock()
	fmt.Fprintf(w, "door unlocked!")
}

func main() {
	doorbot := NewDoorbot(23) //Pin 23 corresponds to GPIO4
	log.Fatal(http.ListenAndServe(":80", doorbot))
}