SenseHAT + NATS Draw https://github.com/peterhellberg/natsdraw

nd-matrix.go

package main

import (
	"image"
	"image/color"
	"math"
	"math/rand"
	"time"

	"github.com/peterhellberg/natsdraw"
)

const w, h = 8, 8

func main() {
	m, err := natsdraw.New("sense.natsdraw", image.Rect(0, 0, w, h))
	if err != nil {
		panic(err)
	}

	rand.Seed(123456)

	particles := []*particle{}

	fall := func(fx, fy float64) {
		speed := 1 + (8.0 * rand.Float64())
		particles = append(particles, newParticle(fx, fy, speed, color.RGBA{0, uint8(32 + rand.Intn(224)), 0, 255}))
	}

	for i := 0; i < 32; i++ {
		fall(float64(rand.Intn(w)), float64(rand.Intn(h)))
	}

	c := time.Tick(16 * time.Millisecond)

	for range c {
		for _, p := range particles {
			p.update(0.06)
			m.Set(int(p.position.X), int(p.position.Y), p.color)
		}
	}
}

type particle struct {
	position vec
	velocity vec
	color    color.RGBA
}

func newParticle(x, y, speed float64, c color.RGBA) *particle {
	return &particle{
		position: vec{x, y},
		velocity: vec{
			X: speed * math.Cos(1.570),
			Y: -speed * math.Sin(1.570),
		},
		color: c,
	}
}

func (p *particle) update(dt float64) {
	p.position.X += p.velocity.X * dt
	p.position.Y += p.velocity.Y * dt

	if p.position.Y < 0 {
		p.position.Y = 8 + float64(rand.Intn(h))
		p.position.X = float64(rand.Intn(w))
	}
}

type vec struct {
	X float64
	Y float64
}

nd-pixel.go

package main

import (
	"image"
	"image/color"

	"github.com/faiface/pixel"
	"github.com/faiface/pixel/imdraw"
	"github.com/faiface/pixel/pixelgl"
	"github.com/peterhellberg/natsdraw"
)

func run() {
	m, err := natsdraw.New("sense.natsdraw", image.Rect(0, 0, 8, 8))
	if err != nil {
		panic(err)
	}

	s := 32
	c, r := m.Bounds().Max.X, m.Bounds().Max.Y
	w, h := c*s, r*s

	win, err := pixelgl.NewWindow(pixelgl.WindowConfig{
		Bounds:      pixel.R(0, 0, float64(w), float64(h)),
		VSync:       true,
		Undecorated: true,
	})
	if err != nil {
		panic(err)
	}

	win.Clear(color.RGBA{0, 0, 0, 255})

	for !win.Closed() {

		imd := imdraw.New(nil)

		for x := 0; x < c; x++ {
			for y := 0; y < r; y++ {
				imd.Color = m.At(x, y)
				imd.Push(pixel.V(float64(x*s+s/2), float64(y*s+s/2)))
				imd.Circle(float64(s)/2.1, 0)
			}
		}

		imd.Draw(win)

		win.SetClosed(win.JustPressed(pixelgl.KeyEscape) || win.JustPressed(pixelgl.KeyQ))
		win.Update()
	}
}

func main() {
	pixelgl.Run(run)
}

nd-plasma.go

package main

import (
	"image"
	"time"

	"github.com/peterhellberg/natsdraw"
	"github.com/peterhellberg/plasma"
	"github.com/peterhellberg/plasma/palette"
)

func main() {
	w, h, i := 8, 8, 0

	m, err := natsdraw.New("sense.natsdraw", image.Rect(0, 0, w, h))
	if err != nil {
		panic(err)
	}

	c := time.Tick(64 * time.Millisecond)

	for range c {
		i++

		pi := plasma.New(w*16, h*16, 2.5).Image(w, h, i, palette.DefaultGradient)

		w, h := m.Bounds().Max.X, m.Bounds().Max.Y

		for x := 0; x < w; x++ {
			for y := 0; y < h; y++ {
				m.Set(x, y, pi.At(x, y))
			}
		}
	}
}

nd-random.go

package main

import (
	"image"
	"image/color"
	"math/rand"
	"time"

	"github.com/peterhellberg/natsdraw"
)

const seed = 123456

func main() {
	rand.Seed(seed)

	m, err := natsdraw.New("sense.natsdraw", image.Rect(0, 0, 8, 8))
	if err != nil {
		panic(err)
	}

	c := time.Tick(128 * time.Millisecond)

	for range c {
		for x := 0; x < 8; x++ {
			for y := 0; y < 8; y++ {
				m.Set(x, y, color.NRGBA{
					uint8(rand.Intn(256)),
					uint8(rand.Intn(256)),
					uint8(rand.Intn(256)),
					255,
				})
			}
		}
	}
}

nd-sense.go

package main

import (
	"fmt"
	"image"
	"os"
	"os/signal"

	"github.com/nathany/bobblehat/sense/screen"
	"github.com/peterhellberg/natsdraw"
)

func main() {
	m, err := natsdraw.New("sense.natsdraw", image.Rect(0, 0, 8, 8), natsdraw.Connect("nats://192.168.1.12:4222"))
	if err != nil {
		panic(err)
	}

	screen.Clear()

	signals := make(chan os.Signal, 1)
	signal.Notify(signals, os.Interrupt, os.Kill)

	for {
		select {
		case <-signals:
			fmt.Println("")
			screen.Clear()
			return
		default:
			screen.DrawImage(m)
		}
	}
}

Installation of gnatsd

go get github.com/nats-io/gnatsd or brew install gnatsd

Sense HAT

nd-sense.go draws a *natsdraw.Image on the Sense HAT LEDs using bobblehat