SjB / goembed

Raspberry Pi development in Go

goembed - Go library for embedded development (like the Raspberry Pi)

The Raspberry Pi (RPi) is a great little linux board with readily available GPIO, SPI, i2c and UART connectivity. This is a library designed to make controlling things using Go on a RPi easy and fun!

Reading a K-type thermocouple using a MAX31855 looks like this:

package main

import (
	_ "github.com/bpowers/goembed/arch/raspberrypi"
	"github.com/bpowers/goembed/device"
	"github.com/bpowers/goembed/platform"
	"log"
)

func main() {
	maxSPI, err := platform.NewSPIPair(0, 0)
	if err != nil {
		log.Fatalf("platform.NewSPIPair(0, 0): %s\n", err)
	}

	tc1, err := device.Max31855(maxSPI)
	if err != nil {
		log.Fatalf("devices.NewMax31855(): %s", err)
	}
	defer tc1.Close()

	temp, err := tc1.Read()
	log.Printf("on startup, temp is %v (err: %v)", temp, err)
}

and blinking an LED once a second looks like this:

package main

import (
	_ "github.com/bpowers/goembed/arch/raspberrypi"
	"github.com/bpowers/goembed/platform"
	"log"
	"time"
)

const LEDPin = 22

func main() {
	pin, err := platform.OpenGPIO(LEDPin, platform.GPOutput)
	if err != nil {
		log.Fatalf("platform.OpenGPIO(LEDPin, platform.GPOutput): %s", err)
	}
	defer pin.Close()

	var desired byte = 0
	timer := time.Tick(500 * time.Millisecond)
	for {
		<-timer
		desired = (desired+1)%2
		pin.Write(desired)
	}
}

Supported systems

I am developing this on a Fedora 18 install which uses a rpi-3.6.y kernel. I would hope that it Just Works on other Linux distros with a similar kernel, but if you run into issues I am happy to look into them.

The idea is that other systems (like the BeagleBoard) could implement GPIO, SPI, and friends and live in arch/beagleboard, etc. Switching deployment targets would simply require updating some consts that represent which functionality is on which IO pins, and changing the import at the top of main.go.

license

goembed is offered under the MIT license, see LICENSE for details.