Trigger iPhone 4s flash with magnetic sensor

I am building a prototype for an idea involving a zoetrope type mechanism ( ), but I have practically no electronics/programming experience. I only need one small electronics component for the whole thing to work; a magnetic sensor run through the arduino to the iphone to trigger its LED flash. The rotating zoetrope disk will have small magnets along the edge to trigger the sensor, which causes the LED to flash in sync with the rotation speed. I also to be able to use other iphone apps simultaneously as the LED is flashing, such as the video camera.

Again, i have zero electronics experience, but i feel this is a fairly simple task.

Any advice appreciated! Thanks, Slam

How are you interfacing to the iPhone, and why? Why not provide your own flash? Using a several hundred dollar phone for the sake of a two dollar LED seems crazy (to me)

Perhaps that video was a bad example, what i am doing is 2d not 3d. I already own the iphone. I will have it streaming live video of the animations to my laptop, so i was hoping i could just capitalize on the built in LED. The phone will also be mounted on a track so it can move around, and it would be useful in my case if the LED could move with it. I could very well use a independent flash, however since it is moving around using the built in LED would keep things streamline.

When this thing is in action, i will not be controlling anything from the iphone. I need it to just stream video to my computer while simultaneously acting a synchronized strobe light.

so i was hoping i could just capitalize on the built in LED.

It will cost you more in leads and software license to use your iPhone for this. Epically given that you don't know what you are doing.

I could very well use a independent flash,

By far the best option.

Another important note,

the magnetic sensor will be mounted with the iphone 'cart' that moves on the track. Therefore it would be best if the sensor could communicate wirelessly to the arduino, and the arduino relay that information wirelessly back to the iphone. sensor -> arduino -> iphone -> laptop

For beginner purposes though, it does not have to be wireless, i can make that improvement later on.

it does not have to be wireless,

USB? What are iPhone APIs like for flash control?


If i understood you right, you have a spinning drum (or something) and want to capture a video like this?

I belive the best solution is to use a digital camera, connect it to your arduino (must ones have trigger-outlets you can use for this), and shoot a picture every time a magnet passes the sensor.

At the end you make a video of the taken pictures.

Problems with your iphone-solution: - you have to connect the arduino to the iphone - have to write an iOS-Application to trigger the flash and stream a video to your computer - everytime the flash triggers, the video will over-expose because the sensor doesn't react that fast. - if you capture a video with the iphone, you'll have blurry frames between the flash-frames