Vary framerate by env

Signed-off-by: Martyn Ranyard <m@rtyn.berlin>

cmd/ledcontroller-server/main.go

@@ -30,9 +30,11 @@ var overrideEffect queue.QueueItem
 var overrideFlag = make(chan queue.QueueItem, 1)
 var previousEffect queue.QueueItem
 
+var msDelay = 0
+
 func foreverLoop() {
 	for /*ever*/ {
-		time.Sleep(40 * time.Millisecond) //25fps
+		time.Sleep(time.Duration(msDelay) * time.Millisecond) //25fps
 		for u := 0; u < universeCount; u++ {
 			sema <- struct{}{} // acquire token
 			channels[u] <- currentFrame[u]
@@ -75,6 +77,10 @@ func main() {
 	if err != nil {
 		PanelHeight = 15
 	}
+	msDelay, err = strconv.Atoi(os.Getenv("MS_DELAY"))
+	if err != nil {
+		msDelay = 40
+	}
 
 	universeCount = int(math.Ceil(float64(PanelHeight*PanelWidth*3) / 510))
 	fmt.Printf("Universe count is %d\n", universeCount)