feat(brake): display brake power with 4 colors

pkg/led/led.go

@@ -21,6 +21,7 @@ func init() {
 var (
 	ColorBlack  = Color{0, 0, 0}
 	ColorRed    = Color{255, 0, 0}
+	ColorPurple = Color{255, 0, 255}
 	ColorYellow = Color{255, 255, 0}
 	ColorGreen  = Color{0, 255, 0}
 	ColorBlue   = Color{0, 0, 255}
@@ -145,6 +146,7 @@ func (l *PiColorLed) blink(freq float64) {
 var setLed = func(v int, led gpio.PinIO, mutex *sync.Mutex) {
 	mutex.Lock()
 	defer mutex.Unlock()
+
 	lvl := gpio.High
 	if v == 0 {
 		lvl = gpio.Low

pkg/part/part.go

@@ -161,7 +161,17 @@ func (p *LedPart) updateColor() {
 	defer p.muThrottle.Unlock()
 
 	if p.throttle <= -0.05 {
-		p.led.SetColor(led.Color{Red: int(p.throttle * -255)})
+		col := led.ColorWhite
+		if p.throttle <= -0.25 {
+			col = led.ColorYellow
+			if p.throttle <= -0.5 {
+				col = led.ColorRed
+				if p.throttle <= -0.75 {
+					col = led.ColorPurple
+				}
+			}
+		}
+		p.led.SetColor(col)
 		return
 	}
 

pkg/part/part_test.go

@@ -138,17 +138,22 @@ func TestLedPart_OnThrottle(t *testing.T) {
 		{
 			"slow brake",
 			testtools.NewFakeMessageFromProtobuf("throttle", &events.ThrottleMessage{Throttle: -0.06}),
-			led.Color{Red: 15},
+			led.ColorWhite,
 		},
 		{
 			"normal brake",
-			testtools.NewFakeMessageFromProtobuf("throttle", &events.ThrottleMessage{Throttle: -0.5}),
+			testtools.NewFakeMessageFromProtobuf("throttle", &events.ThrottleMessage{Throttle: -0.4}),
-			led.Color{Red: 127},
+			led.ColorYellow,
+		},
+		{
+			"normal high brake",
+			testtools.NewFakeMessageFromProtobuf("throttle", &events.ThrottleMessage{Throttle: -0.6}),
+			led.ColorRed,
 		},
 		{
 			"high brake",
 			testtools.NewFakeMessageFromProtobuf("throttle", &events.ThrottleMessage{Throttle: -1.}),
-			led.ColorRed,
+			led.ColorPurple,
 		},
 	}