example: naive debouncing for pininterrupt example

src/examples/pininterrupt/pininterrupt.go

@@ -3,7 +3,7 @@ package main
 // This example demonstrates how to use pin change interrupts.
 //
 // This is only an example and should not be copied directly in any serious
-// circuit, because it lacks an important feature: debouncing.
+// circuit, because it only naively implements an important feature: debouncing.
 // See: https://en.wikipedia.org/wiki/Switch#Contact_bounce
 
 import (
@@ -17,6 +17,8 @@ const (
 	led    = machine.LED
 )
 
+var lastPress time.Time
+
 func main() {
 	var lightLed volatile.Register8
 	lightLed.Set(0)
@@ -33,6 +35,13 @@ func main() {
 
 	// Set an interrupt on this pin.
 	err := button.SetInterrupt(buttonPinChange, func(machine.Pin) {
+
+		// Ignore events that are too close to the last registered press (debouncing)
+		if time.Since(lastPress) < 100*time.Millisecond {
+			return
+		}
+		lastPress = time.Now()
+
 		if lightLed.Get() != 0 {
 			lightLed.Set(0)
 			led.Low()