new API for shifter driver.

this doesn't break existing code, but it might no longer work as expected

examples/shifter/main.go

@@ -7,42 +7,47 @@ import (
 	"tinygo.org/x/drivers/shifter"
 )
 
+const (
+	BUTTON_LEFT = iota
+	BUTTON_UP
+	BUTTON_DOWN
+	BUTTON_RIGHT
+	BUTTON_SELECT
+	BUTTON_START
+	BUTTON_A
+	BUTTON_B
+)
+
 func main() {
 	buttons := shifter.New(shifter.EIGHT_BITS, machine.BUTTON_LATCH, machine.BUTTON_CLK, machine.BUTTON_OUT)
 	buttons.Configure()
 
 	for {
-		// Slower
-		for i := 0; i < 8; i++ {
-			if buttons.Pins[i].Get() {
-				println("Button", i, "pressed")
-			}
-		}
+		// Update the pins state, to later be returned by .Get()
+		buttons.Read8Input()
 
-		// Faster
-		pressed, _ := buttons.Read8Input()
-		if pressed&machine.BUTTON_LEFT_MASK > 0 {
+		if buttons.Pins[BUTTON_LEFT].Get() {
 			println("Button LEFT pressed")
 		}
-		if pressed&machine.BUTTON_UP_MASK > 0 {
+		if buttons.Pins[BUTTON_UP].Get() {
 			println("Button UP pressed")
 		}
-		if pressed&machine.BUTTON_DOWN_MASK > 0 {
+		if buttons.Pins[BUTTON_DOWN].Get() {
 			println("Button DOWN pressed")
 		}
-		if pressed&machine.BUTTON_RIGHT_MASK > 0 {
+		if buttons.Pins[BUTTON_RIGHT].Get() {
 			println("Button RIGHT pressed")
 		}
-		if pressed&machine.BUTTON_SELECT_MASK > 0 {
+		if buttons.Pins[BUTTON_SELECT].Get() {
 			println("Button SELECT pressed")
 		}
-		if pressed&machine.BUTTON_START_MASK > 0 {
+		if buttons.Pins[BUTTON_START].Get() {
 			println("Button START pressed")
 		}
-		if pressed&machine.BUTTON_A_MASK > 0 {
+		if buttons.Pins[BUTTON_A].Get() {
 			println("Button A pressed")
 		}
-		if pressed&machine.BUTTON_B_MASK > 0 {
+		if buttons.Pins[BUTTON_B].Get() {
 			println("Button B pressed")
 		}
 		time.Sleep(100 * time.Millisecond)