Pin HAL to break dependency of drivers from TinyGo's machine package

examples/rpio/main.go

@@ -0,0 +1,68 @@
+package main
+
+// Example program for the ST7735 display (Waveshare 1.44" LCD HAT) using the rpio driver on a Raspberry Pi.
+
+import (
+	"fmt"
+	"image/color"
+	"time"
+
+	go_rpio "github.com/stianeikeland/go-rpio/v4"
+	"tinygo.org/x/drivers/rpio"
+	"tinygo.org/x/drivers/st7735"
+)
+
+var (
+	black  = color.RGBA{0, 0, 0, 255}
+	colors = [...]color.RGBA{
+		{255, 0, 0, 255},   // red
+		{0, 255, 0, 255},   // green
+		{0, 0, 255, 255},   // blue
+		{255, 255, 0, 255}, // yellow
+	}
+)
+
+func main() {
+	if err := go_rpio.Open(); err != nil {
+		fmt.Println("Error opening GPIO:", err)
+		return
+	}
+	defer go_rpio.Close()
+
+	// Initialize SPI and pins
+	spi := rpio.NewSPI()
+	resetPin := rpio.NewPin(27)
+	dcPin := rpio.NewPin(25)
+	csPin := rpio.NewPin(8)
+	blPin := rpio.NewPin(24)
+
+	// Initialize display
+	device := st7735.New(spi, resetPin, dcPin, csPin, blPin)
+	device.Configure(st7735.Config{
+		Width:        128,
+		Height:       128,
+		Model:        st7735.GREENTAB,
+		RowOffset:    3,
+		ColumnOffset: 2,
+	})
+	device.InvertColors(false)
+	device.EnableBacklight(true)
+	device.IsBGR(true) // no effect w/o rotation!
+	device.SetRotation(st7735.NO_ROTATION)
+
+	width, height := device.Size()
+
+	// Clear display
+	device.FillScreen(black)
+
+	// Draw rectangles in a loop, clockwise rotation of colors
+	pos := 0
+	for {
+		device.FillRectangle(0, 0, width/2, height/2, colors[(pos+0)%len(colors)])              // top left
+		device.FillRectangle(0, height/2, width/2, height/2, colors[(pos+1)%len(colors)])       // bottom left
+		device.FillRectangle(width/2, height/2, width/2, height/2, colors[(pos+2)%len(colors)]) // bottom right
+		device.FillRectangle(width/2, 0, width/2, height/2, colors[(pos+3)%len(colors)])        // top right
+		pos++
+		time.Sleep(1 * time.Second)
+	}
+}