Nikon Hacks Part IV

Triggering Nikon Flash

With Arduino

 

It's miserable weather here in Consett, so I'm staying in and hacking a Nikon flash cable so I can trigger a flash with an Arduino. The cable is only about £10 on Amazon.  http://pinoutsguide.com/ is a very useful link for pinouts of loads of electronic stuff.

WARNING - do not a attach your camera to the hot-shoe whilst it is attached to the Arduino, you may damage the camera by shorting out things or applying voltages to the camera circuits (very expensive mistake). If you blow an arduino chip , they cost just a few dollars, but a new Camera could cost you hundreds even thousands!

 

Nikon Hot-shoe cable Pinout 

When the flash is On and Ready (ready light is lit on the flash:

1. Trigger (+3.7)

2. Detect (+5v)

3. Ready(+5v)

4. Quench(+4v)

5. Ground(0v)

Testing

To simply trigger the flash you make the circuit between 1 and 5 (trigger and ground).  The ground (5) is connected to Arduino GND and 1 (trigger) is connected to a digital pin (in my case PIN13) which will go from HIGH to LOW, so triggering the flash in manual mode.When attached to my flash, the trigger pin reads +5v approx.

 You can test this by loading the Blink demo from the Arduino IDE and playing with the delay(). I did this initially by just holding the Arduino jumper wires onto the pinout surfaces of the hot-shoe. It is recommended to use a diode between the GND and the trigger pin (13)  to protect against voltage surges and ESD.

Code:------------------------------------------------------

/*
  FLASH
  Trigger a Camera Flash repeatedly.

  This example code is in the public domain.
 */

// Pin 13 has an LED connected on most Arduino boards so you
//should see the LED blink as well as the flash being triggered.

int flash = 13;

// the setup routine runs once when you press reset:
void setup() {               
  // initialize the digital pin as an output.
  pinMode(flash, OUTPUT);    
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(flash, HIGH);   //  (HIGH is the 5v voltage level)
  delay(200);               // wait
  digitalWrite(flash, LOW);    // trigger the FLASH by making the voltage LOW
  delay(100);               // wait
}

End Code:------------------------------------------------------ 

Why?

Now I have a way of triggering the camera shutter (using the IR sensor) and the flash (using the hot-shoe cable) independently via the Arduino. It gives me greater creative and technical control over the exposures, remote or automatic triggering and special effects.

Next physically adapting the cable by soldering wires inside the cable's case.