microbitmatrixtest.go

package main

import (
	"image/color"

	"tinygo.org/x/drivers/microbitmatrix"
)

var (
	display microbitmatrix.Device
	dark    = color.RGBA{0, 0, 0, 0}
	light  = color.RGBA{255, 255, 255, 255}
)

func main() {
	display = microbitmatrix.New()
	display.Configure(microbitmatrix.Config{
		Rotation: 0,
	})
	display.ClearDisplay()
	for line := int16(0); line < 5; line++ {
		for row := int16(0); row < 5; row++ {
			display.SetPixel(line, row, light)
		}
	}
	display.Display()
}

solution provided in https://gist.github.com/conejoninja/a4acf6f637f8022b91c821f4ef0e7044