Arduino powered simple LANC remote

This is a follow up on the previous post on starting video recording using the LANC port.

The Arduino sketch below let's you send the REC command, two ZOOM and two FOCUS commands. The LANC commands are arrays containing the bit values for byte 0 and byte 1 of the specific command. All switches should be push buttons.

/*
SIMPLE LANC REMOTE
Version 1.0
Sends LANC commands to the LANC port of a video camera.
Tested with a Canon XF300 camcorder
For the interface circuit interface see 
http://controlyourcamera.blogspot.com/2011/02/arduino-controlled-video-recording-over.html
Feel free to use this code in any way you want.
2011, Martin Koch

"LANC" is a registered trademark of SONY.
CANON calls their LANC compatible port "REMOTE".
*/

#define cmdPin 7 
#define lancPin 11
#define recButton 6
#define zoomOutButton 5
#define zoomInButton 4
#define focusNearButton 3
#define focusFarButton 2
int cmdRepeatCount;
int bitDuration = 104; //Duration of one LANC bit in microseconds. 


//LANC commands byte 0 + byte 1
//Tested with Canon XF300

//Start-stop video recording
boolean REC[] = {LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW,   LOW,LOW,HIGH,HIGH,LOW,LOW,HIGH,HIGH}; //18 33

//Zoom in from slowest to fastest speed
boolean ZOOM_IN_0[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,LOW,LOW,LOW,LOW}; //28 00
boolean ZOOM_IN_1[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,LOW,LOW,HIGH,LOW}; //28 02
boolean ZOOM_IN_2[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,LOW,HIGH,LOW,LOW}; //28 04
boolean ZOOM_IN_3[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,LOW,HIGH,HIGH,LOW}; //28 06
boolean ZOOM_IN_4[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,HIGH,LOW,LOW,LOW}; //28 08
boolean ZOOM_IN_5[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,HIGH,LOW,HIGH,LOW}; //28 0A
boolean ZOOM_IN_6[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,HIGH,HIGH,LOW,LOW}; //28 0C
boolean ZOOM_IN_7[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,LOW,HIGH,HIGH,HIGH,LOW}; //28 0E

//Zoom out from slowest to fastest speed
boolean ZOOM_OUT_0[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,LOW,LOW,LOW,LOW}; //28 10
boolean ZOOM_OUT_1[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,LOW,LOW,HIGH,LOW}; //28 12
boolean ZOOM_OUT_2[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,LOW,HIGH,LOW,LOW}; //28 14
boolean ZOOM_OUT_3[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,LOW,HIGH,HIGH,LOW}; //28 16
boolean ZOOM_OUT_4[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW}; //28 18
boolean ZOOM_OUT_5[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,HIGH,LOW,HIGH,LOW}; //28 1A
boolean ZOOM_OUT_6[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,HIGH,HIGH,LOW,LOW}; //28 1C
boolean ZOOM_OUT_7[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,LOW,LOW,HIGH,HIGH,HIGH,HIGH,LOW}; //28 1E

//Focus control. Camera must be switched to manual focus
boolean FOCUS_NEAR[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,HIGH,LOW,LOW,LOW,HIGH,HIGH,HIGH}; //28 47
boolean FOCUS_FAR[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,HIGH,LOW,LOW,LOW,HIGH,LOW,HIGH}; //28 45

boolean FOCUS_AUTO[] = {LOW,LOW,HIGH,LOW,HIGH,LOW,LOW,LOW,   LOW,HIGH,LOW,LOW,LOW,LOW,LOW,HIGH}; //28 41

//boolean POWER_OFF[] = {LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW,   LOW,HIGH,LOW,HIGH,HIGH,HIGH,HIGH,LOW}; //18 5E
//boolean POWER_ON[] = {LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW,   LOW,HIGH,LOW,HIGH,HIGH,HIGH,LOW,LOW}; //18 5C  Doesn't work because there's no power supply from the LANC port when the camera is off
//boolean POWER_OFF2[] = {LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW,   LOW,LOW,HIGH,LOW,HIGH,LOW,HIGH,LOW}; //18 2A Turns the XF300 off and then on again
//boolean POWER_SAVE[] = {LOW,LOW,LOW,HIGH,HIGH,LOW,LOW,LOW,   LOW,HIGH,HIGH,LOW,HIGH,HIGH,LOW,LOW}; //18 6C Didn't work



void setup() {

 pinMode(lancPin, INPUT); //listens to the LANC line
 pinMode(cmdPin, OUTPUT); //writes to the LANC line

 pinMode(recButton, INPUT); //start-stop recording button
        digitalWrite(recButton, HIGH); //turn on an internal pull up resistor
        pinMode(zoomOutButton, INPUT); 
        digitalWrite(zoomOutButton, HIGH);
        pinMode(zoomInButton, INPUT); 
        digitalWrite(zoomInButton, HIGH);
        pinMode(focusNearButton, INPUT); 
        digitalWrite(focusNearButton, HIGH);
        pinMode(focusFarButton, INPUT); 
        digitalWrite(focusFarButton, HIGH);
        
        digitalWrite(cmdPin, LOW); //set LANC line to +5V
        delay(5000); //Wait for camera to power up completly
        bitDuration = bitDuration - 8; //Writing to the digital port takes about 8 microseconds so only 96 microseconds are left for each bit
}

void loop() {
  
  
   if (!digitalRead(recButton)) {
    lancCommand(REC); 
  }
  
  if (!digitalRead(zoomOutButton)) {
    lancCommand(ZOOM_OUT_4); 
  }
  
  if (!digitalRead(zoomInButton)) {
    lancCommand(ZOOM_IN_4); 
  }
  
  if (!digitalRead(focusNearButton)) {
    lancCommand(FOCUS_NEAR); 
  }
  
  if (!digitalRead(focusFarButton)) {
    lancCommand(FOCUS_FAR); 
  }
}



void lancCommand(boolean lancBit[]) {
       
        cmdRepeatCount = 0;
  
   while (cmdRepeatCount < 5) {  //repeat 5 times to make sure the camera accepts the command

                while (pulseIn(lancPin, HIGH) < 5000) {   
                  //"pulseIn, HIGH" catches any 0V TO +5V TRANSITION and waits until the LANC line goes back to 0V 
                  //"pulseIn" also returns the pulse duration so we can check if the previous +5V duration was long enough (>5ms) to be the pause before a new 8 byte data packet
                  //Loop till pulse duration is >5ms
                }

   //LOW after long pause means the START bit of Byte 0 is here
   delayMicroseconds(bitDuration);  //wait START bit duration

   //Write the 8 bits of byte 0 
                        //Note that the command bits have to be put out in reverse order with the least significant, right-most bit (bit 0) first
                        for (int i=7; i>-1; i--) {
     digitalWrite(cmdPin, lancBit[i]);  //Write bits. 
     delayMicroseconds(bitDuration); 
                        }
   
                        //Byte 0 is written now put LANC line back to +5V
                        digitalWrite(cmdPin, LOW);
                        delayMicroseconds(10); //make sure to be in the stop bit before byte 1
                        
                        while (digitalRead(lancPin)) { 
                          //Loop as long as the LANC line is +5V during the stop bit
                        }

                        //0V after the previous stop bit means the START bit of Byte 1 is here
         delayMicroseconds(bitDuration);  //wait START bit duration
      
         //Write the 8 bits of Byte 1
                        //Note that the command bits have to be put out in reverse order with the least significant, right-most bit (bit 0) first
                        for (int i=15; i>7; i--) {
              digitalWrite(cmdPin,lancBit[i]);  //Write bits 
             delayMicroseconds(bitDuration);
                        }
 
                        //Byte 1 is written now put LANC line back to +5V
                        digitalWrite(cmdPin, LOW); 

   cmdRepeatCount++;  //increase repeat count by 1
   
   /*Control bytes 0 and 1 are written, now don’t care what happens in Bytes 2 to 7
   and just wait for the next start bit after a long pause to send the first two command bytes again.*/
  

 }//While cmdRepeatCount < 5
}