Working code

main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"machine"
+	"time"
+)
+
+func main() {
+	// 500Hz
+	var period uint64 = 1e9 / 500
+
+	pin := machine.LED
+	pwm := machine.PWM4
+
+	pin.Configure(machine.PinConfig{Mode: machine.PinPWM})
+
+	err := pwm.Configure(machine.PWMConfig{Period: period})
+	if err != nil {
+		println(err.Error())
+	}
+	ch, err := pwm.Channel(pin)
+	if err != nil {
+		println(err.Error())
+	}
+
+	pwm.SetTop(uint32(255))
+
+	for {
+		// Fade in
+		for i := 0; i <= 255; i++ {
+			pwm.Set(ch, uint32(i))
+			time.Sleep(time.Millisecond * 10)
+		}
+
+		// Fade out
+		for i := 255; i >= 0; i-- {
+			pwm.Set(ch, uint32(i))
+			time.Sleep(time.Millisecond * 10)
+		}
+
+		// Wait one second
+		time.Sleep(time.Millisecond * 1000)
+	}
+}