assume 0 for all values not sent in transmission (closes #4)

README.md

@@ -41,18 +41,15 @@ Note that mode 0 only responds to ENTTEC label 6 and outputs to universe 0 in th
 #### callback (void)
 A callback function to call when a DMX transmission is received. This function should have three parameters:
 
-| parameter          | description                                                                                                                |
-|--------------------|----------------------------------------------------------------------------------------------------------------------------|
-| int universe       | An integer starting at `0` with which universe received the DMX message                                                    |
-| unsigned int index | The number of channels starting at 0 that received a message where DMX channel 1 is index 0, DMX channel 2 is index 1, etc |
-| char buffer[512]   | The array of DMX values where the index of the array correponds with the `index` parameter                                 |
+| parameter          | description                                                             |
+|--------------------|-------------------------------------------------------------------------|
+| int universe       | An integer starting at `0` with which universe received the DMX message |
+| char buffer[512]   | The array of 512 DMX values starting at 0                               |
 
 Example function that lights an LED with channel 1 on universe 0:
 ```cpp
-void myDMXCallback(int universe, unsigned int index, char buffer[512]) {
-  unsigned int count;
-  count = index;
-  for (index=0; index <= count; index++) { // for each channel
+void myDMXCallback(int universe, char buffer[512]) {
+  for (int index=0; index < 512; index++) { // for each channel, universe starts at 0
     int channel = index + 1; // channel starts at 0, so index 0 is DMX channel 1 and index 511 is DMX channel 512
     int value = buffer[index]; // DMX value 0 to 255
     if (universe == 0 && channel == 1) analogWrite(LED_PIN, value); // LED on channel 1 on universe 0

examples/Simple_Test/Simple_Test.ino

@@ -29,11 +29,8 @@ const byte LED_PIN = 13;
 #define BAUDRATE 115200
 
 // receive a DMX transmission
-void myDMXCallback(int universe, unsigned int index, char buffer[512]) {
-  // universe starts at 0
-  unsigned int count;
-  count = index;
-  for (index=0; index <= count; index++) { // for each channel
+void myDMXCallback(int universe, char buffer[512]) {
+  for (int index=0; index < 512; index++) { // for each channel, universe starts at 0
     int channel = index + 1; // channel starts at 0, so index 0 is DMX channel 1 and index 511 is DMX channel 512
     int value = buffer[index]; // DMX value 0 to 255
     if (universe == 0 && channel == 1) analogWrite(LED_PIN, value); // LED on channel 1 on universe 0
@@ -58,4 +55,4 @@ void setup() {
 
 void loop() {
   myDMXUsb.listen();
-}
+}

src/DMXUSB.cpp

@@ -30,7 +30,7 @@
 #define STATE_END      5
 
 // Initialize DMXUSB serial port
-DMXUSB::DMXUSB(Stream &serial, int baudrate, int mode, void (*dmxInCallback)(int universe, unsigned int index, char buffer[512])) {
+DMXUSB::DMXUSB(Stream &serial, int baudrate, int mode, void (*dmxInCallback)(int universe, char buffer[512])) {
   _serial = &serial;
   _baudrate = baudrate;
   _mode = mode;
@@ -66,6 +66,7 @@ void DMXUSB::listen() {
         // second bit: message label
         case STATE_LABEL:
           label = b; // record the message label
+          if (label == 6 || label == 100 || label == 101) for (int i = 0; i < 512; i++) _buffer[i] = (byte)0x00; // set buffer to all zero values if receiving DMX data
           state = STATE_LEN_LSB; // move to next bit
           break;
 
@@ -94,7 +95,6 @@ void DMXUSB::listen() {
           }
           count = count - 1; // decrease the data count
           if (count == 0) {
-            //for (int i = 512; i >= (index-1); i--) _buffer[i] = (byte)0x00; // set unsent values to 0 // for all unsent values (protocol says 0 values are omitted after last value)
             state = STATE_END; // if no more data, move on to last bit
           }
           break;
@@ -163,13 +163,13 @@ void DMXUSB::listen() {
 
             else if (label == 6 || label == 100 || label == 101) { // receive DMX message to both universes
               //if (index > 1) {
-              if (label == 6 && _mode == 0) this->DMXUSB::_dmxInCallback(0, index, _buffer); // receive label==6 DMX message to first universe for Enttec-like ultraDMX Micro device
+              if (label == 6 && _mode == 0) this->DMXUSB::_dmxInCallback(0, _buffer); // receive label==6 DMX message to first universe for Enttec-like ultraDMX Micro device
               if (label == 6 && _mode == 1) {  // receive label==6 DMX message to both universes for ultraDMX Pro device
-                this->DMXUSB::_dmxInCallback(0, index, _buffer);
-                this->DMXUSB::_dmxInCallback(1, index, _buffer);
+                this->DMXUSB::_dmxInCallback(0, _buffer);
+                this->DMXUSB::_dmxInCallback(1, _buffer);
               }
-              if (label == 100 || _mode == 1) this->DMXUSB::_dmxInCallback(0, index, _buffer); // receive label==100 DMX message to first universe for ultraDMX Pro device
-              if (label == 101 || _mode == 1) this->DMXUSB::_dmxInCallback(1, index, _buffer); // receive label==101 DMX message to second universe for ultraDMX Pro device
+              if (label == 100 || _mode == 1) this->DMXUSB::_dmxInCallback(0, _buffer); // receive label==100 DMX message to first universe for ultraDMX Pro device
+              if (label == 101 || _mode == 1) this->DMXUSB::_dmxInCallback(1, _buffer); // receive label==101 DMX message to second universe for ultraDMX Pro device
               //}
             }
           }
@@ -181,4 +181,4 @@ void DMXUSB::listen() {
       }
     }
   }
-}
+}

src/DMXUSB.h

@@ -28,15 +28,15 @@
 
 class DMXUSB {
   public:
-    DMXUSB(Stream &serial, int baudrate, int mode, void (*dmxInCallback)(int universe, unsigned int index, char buffer[512]));
+    DMXUSB(Stream &serial, int baudrate, int mode, void (*dmxInCallback)(int universe, char buffer[512]));
     void listen();
   private:
     char _buffer[512];
     elapsedMillis _timeout;
     Stream *_serial;
     int _baudrate;
     int _mode;
-    void (*_dmxInCallback)(int universe, unsigned int index, char buffer[512]);
+    void (*_dmxInCallback)(int universe, char buffer[512]);
 };
 
 #endif