Canon DIY remote control

How to hack your triggertrap mobile dongle to work with an Arduino

This github-repository contains everything you need to connect your Triggertrap-mobile-dongle to an Arduino. Even if you do not have the Trigger-trap you find all information to either build your own, or how to at least easily trigger your camera with a simple button.

I have been using this setup on my Canon 5D Mark III and it works just fine.

Table of Contents

• Shopping List
• Wiring
• What I learned
  • Audio jack
  • Camera connector
  • How to trigger your camera without a triggertrap
• Ressources

Shopping List

1. Arduino Leonardo
2. Triggertrap mobile kit - (Amazon US)
3. TRRS 3.5mm Jack
4. Cables (3x)
5. Breadboard

Wiring

The wiring is very simple.

1. Arduino pin 3 to Audio-Jack Tip
2. Arduino pin 5 to Audio-Jack Ring 1
3. Arduino ground to Audio-Jack Ring 2 or Sleeve

What I learned

Audio jack

Camera connector

This is only interesting to you if you actually plan to build your own trigger-trap contraption. In this case you might want to actually read this article, as all you need is a button. Meaning: The camera outputs a 1V charge on its shutter-pin and focus-pin. If you ground either of them via the ground-pin you can trigger either action.(see the image below for the 3 pins)

The tricky part is now figuring out how the trigger-trap works internally, so you can hook it up to the Arduino. It turns out that the Trigger-trap uses two transistors to ground the contacts(more info). So you need to apply a charge to the camera connector in order to open the transistor(-switch). However, since the Trigger-trap is supposed to work with iPhones it does not accept a simple DC-charge. You actually need AC for this! Luckily the Arduino can fake AC-charge somewhat with it's PWM-pins. All you need to do is use the Arduinos analogWrite-function.

How to trigger your camera without a triggertrap

If you have a cable that fits into the Camera-remote-trigger port(e.g.: this one) just ground the 2.5mm audio-jack tip with the ground and the camera should get triggered.

This is the Input Serial Pullup concept, which is a very neat way of implementing a button.

Ressources

How the canon remote controller-jack works.
How the trigger-trap mobile dongle works.
iPhone auxiliary uses AC instead of DC.
Fritzing - a great tool for circuit designs - from Potdam, Germany :-).