From f9e969e6e815362fb7284ba4e6e04daf70090fc7 Mon Sep 17 00:00:00 2001
From: Kai Vogelgesang <kai@leafbla.de>
Date: Mon, 30 Aug 2021 10:18:31 +0200
Subject: [PATCH] Cleanup

---
 microcontroller/test.ino | 51 ++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/microcontroller/test.ino b/microcontroller/test.ino
index 2231e22..6ae7007 100644
--- a/microcontroller/test.ino
+++ b/microcontroller/test.ino
@@ -19,7 +19,8 @@
     }
  */
 
-struct InternalBuffer {
+struct InternalBuffer
+{
     char data[512] = {0};
     bool is_fresh = false;
 };
@@ -27,29 +28,32 @@ struct InternalBuffer {
 class DMXTripleBuffer
 {
 public:
-    
-    DMXTripleBuffer() {
+    DMXTripleBuffer()
+    {
         fill_buffer = &_buffers[0];
         drain_buffer = &_buffers[1];
         off_buffer = &_buffers[2];
     }
-    
-    void on_fill_complete() {
+
+    void on_fill_complete()
+    {
         fill_pos = 0;
         fill_buffer->is_fresh = true;
         std::swap(fill_buffer, off_buffer);
     }
-    
-    void on_drain_complete() {
+
+    void on_drain_complete()
+    {
         drain_pos = 0;
         drain_buffer->is_fresh = false;
-        if (off_buffer->is_fresh) {
+        if (off_buffer->is_fresh)
+        {
             std::swap(drain_buffer, off_buffer);
         }
     }
     InternalBuffer *fill_buffer, *drain_buffer, *off_buffer;
     size_t fill_pos = 0, drain_pos = 0;
-        
+
 private:
     InternalBuffer _buffers[3];
 };
@@ -58,18 +62,17 @@ private:
     Some globals
  */
 
+DMXTripleBuffer buffer;   // Triple buffer instance
+bool packet_ready = true; // flag to write header
+
+// send a "Sync." every second if no data is coming in
 unsigned long time_since_last_sync;
 const unsigned long SYNC_TIMEOUT = 1000;
 
-const unsigned int FRAME_TIME = 20; // 20 ms -> 50 FPS
-
-DMXTripleBuffer buffer;
-bool packet_ready = true;
-
-unsigned long pkt_count = 0;
-
 /*
-    main
+    setup
+
+    initialize both Serial connections and write the initial "Sync."
  */
 
 void setup()
@@ -80,7 +83,7 @@ void setup()
     {
         // spin until serial is up
     }
-    
+
     Serial1.begin(250000, SERIAL_8N2); // DMX
     while (!Serial1)
     {
@@ -92,6 +95,15 @@ void setup()
     time_since_last_sync = millis();
 }
 
+/*
+    loop
+
+    continuously poll Serial1 for writing and Serial for reading
+    only read/write as much as fits into the UART buffers to avoid blocking
+
+    since Serial1 is set to 250000 baud, it should be able to write 50 DMX packets per second
+ */
+
 void loop()
 {
 
@@ -101,7 +113,6 @@ void loop()
     {
         send_dmx_header();
         packet_ready = false;
-        pkt_count += 1;
     }
     size_t n = Serial1.availableForWrite();
 
@@ -133,7 +144,7 @@ void loop()
         }
         return;
     }
-    
+
     time_since_last_sync = now;
 
     size_t read = Serial.read(