Attention! If your camera works with a LANC voltage of more than 5V this solution can't be used.
Arduino sketch that repeatetly prints byte 0 and byte 1 of the LANC packet to the Serial Monitor in the Arduino developing environment. Press a button on the remote and watch the command appear.
/*
LANC SNIFFER
Version 1.0
Finds out LANC commands from a REMOTE
For the interface ciruit see
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 lancPin 11
int bitDuration = 104; //Duration of one LANC bit in microseconds.
int lancBit[16];
void setup() {
Serial.begin(9600); //open the serial port
pinMode(lancPin, INPUT); //listens to the LANC line
delay(5000); //Wait for camera to power up completly
bitDuration = bitDuration- 8; //Reading the digital port takes about 8 microseconds so only 96 microseconds are left for each bit
}
void loop() {
readLancCommand();
delay(1000);
}
void readLancCommand() {
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
delayMicroseconds(bitDuration/2); //wait until the middle of bit 0 of byte 0
//Read the 8 bits of byte 0
//Note that the command bits come in in reverse order with the least significant, right-most bit (bit 0) first
for (int i=7; i>-1; i--) {
lancBit[i] = digitalRead(lancPin); //read bits.
delayMicroseconds(bitDuration);
}
//Byte 0 is read
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
delayMicroseconds(bitDuration/2); //wait until the middle of bit 0 of byte 1
//Read the 8 bits of Byte 1
//Note that the command bits have to be read in reverse order with the least significant, right-most bit (bit 0) first
for (int i=15; i>7; i--) {
lancBit[i] = digitalRead(lancPin); //read bits
delayMicroseconds(bitDuration);
}
//Byte 1 is read
//Print byte 0 and byte 1 to the Serial Monitor console of the Arduino developing environment
Serial.println("BITS: ");
for (int i=0; i<16; i++) {
Serial.print((lancBit[i]-1)*-1); //invert the bits
if (i==7) Serial.print(" ");
}
Serial.println("");
}
If you try this with other LANC remotes please post your findings (command / hex values) in the comments. I'm especially interested in the additional commands of the Canon ZR-2000 LANC remote.
I found out the useful PUSH AF code of the ZR-2000 by trial and error. It is 2843 and has to be send repeatetly for a second or two in order to have an effect. The camera has to be in manual focus mode and Push AF invokes auto focus temporarily
