Concurrent blinking.

blink.go

package main

import (
	"github.com/ZachMassia/gofirmata"
	"log"
	"time"
)

func main() {
	a, err := firmata.NewBoard("/dev/ttyACM0", 57600)
	if err != nil {
		log.Fatal(err)
	}
	defer a.Close()

	// Output LED pins
	red := byte(23)
	grn := byte(3)

	// Set modes
	a.SetPinMode(red, firmata.OUTPUT)
	a.SetPinMode(grn, firmata.OUTPUT)

	// Start flashing two LEDs concurently.
	Blink(a, red, time.Tick(250*time.Millisecond))
	Blink(a, grn, time.Tick(500*time.Millisecond))

	// Run for 10 seconds
	quit := time.After(10 * time.Second)
	for {
		select {
		case <-a.Reader:
			// Needed for now to keep the message loop from blocking.
			continue
		case <-quit:
			return
		}
	}
}

// Blink flashes a LED every tick.
func Blink(b *firmata.Board, pin byte, tick <-chan time.Time) {
	state := firmata.LOW
	go func() {
		for _ = range tick {
			if state == firmata.LOW {
				state = firmata.HIGH
			} else {
				state = firmata.LOW
			}
			b.DigitalWrite(pin, state)
		}
	}()
}