Page 4 – Martyn Currey

Breadboarding components

April 18, 2016September 26, 2013 by Martyn

When building prototypes on breadboards I find it useful to have small pre-made components such as 3.5 stereo jack sockets configured to fit breadboards The 3.5 stereo socket is attached to a small piece of board and the connectors from the socket attached to pins that fit in to a breadboard. Red is VCC, black … Read more

Connecting a photo interrupter/optoisolator to an Arduino

April 2, 2024September 16, 2013 by Martyn

In an early version of the camControl device (before the dropController) I used an interrupter/optoisolator to detect the water drops. The plan was to detect the water drop, wait a little bit and then activate the shutter.

There are various different kinds of photo interrupter, different shapes and different sizes but all do the same job.

A photo interrupter has a LED at one side (normally IR) and a photo transistor at the other. When the LED in emitting light the photo transistor allows a current to flow. Remove the light and the current stops.

Photographing Water Drops Using An Arduino Controller

August 14, 2013 by Martyn

I started creating a controller using a single Arduino Nano on a breadboard. Although it was very basic it worked fairly well. It allowed me to control a solenoid valve and trigger the camera shutter. I also added basic camera control and a timelapse function (intervalometer). This part worked well. I could set the frequency … Read more

Photographing Water Drops: Second Go

August 14, 2013August 12, 2013 by Martyn

I had another session photographing water drops. The idea is to create two drops slightly apart. The first drop hits the water, rebounds and creates a column and then the second drop collides with the column. Sounds a lot easier than it really is. Here are some of the results. These are from plain water. … Read more

First Proper Try At Water Drop Photography

October 5, 2013August 4, 2013 by Martyn

I wanted to try taking water drop photos and see what worked and what didn’t. Overall the results were better than I expected but not as good has I had hoped. Lighting is not good but I knew this from the beginning and concentrated on the drops and the timings. Working on the lighting can … Read more

Photographing Water Drops: First Prototype

August 14, 2013August 4, 2013 by Martyn

Here is the camera and stand setup. The stand is a 80cm lab stand. I bought 2 of these with various clamps and supports. Another Taobao special.

Controlling a Solenoid Valve from an Arduino

April 5, 2019July 11, 2013 by Martyn

There is now an updated and more detailed post. See Controlling a Solenoid Valve from an Arduino. Updated.

Using the Arduino to control the solenoid valve is simply a case of setting a pin high for the appropriate amount of time. There is, however, a caveat, the solenoid works at a different voltage to the Arduino and you cannot directly connect the two. In this case a TIP120 transistor is used as a bridge.

The TIP120 allows a small dc voltage (from the Arduino) to switch a larger dc voltage (12V to the solenoid). It can be thought of as a switch, applying a current to B allows current to flow between C to E.

Soleniod Valves

October 20, 2013July 10, 2013 by Martyn

Solenoid valves are used to control the flow of liquids and gasses and they are an ideal way to create water drops. To get started I purchased a small range of different solenoids with the intention of testing them out and seeing which was the best.

Using an Arduino and a optocoupler to activate a camera shutter

August 29, 2018July 6, 2013 by Martyn

There are several ways you can connect an Arduino to a DSLR so that you can use the Arduino to activate the shutter. I chose to use an optocoupler, sometimes called an optoisolator.

Optocoupler

There are many types of optocoupler and you chose one based on the requirements of your circuit. My circuit is a 5V Arduino and a Canon 40D which has about 3.2V on the shutter release. Due to the relatively low voltages there are many suitable optocouplers to pick from. I already had a Fairchild 4N26 so this is the one I used.

4N26

Optocouplers are digital switches. They work by using an LED emitter paired with a photo detector transistor. This means they can be used to allow one circuit to switch a separate circuit without having any electrical contact between the two. Basically, if you put a current through pins 1 and 2 and light the LED the photo detector transistor detects the light from the LED and allows a current to flow through pins 5 and 4. No current on pins 1 and 2 means current does not pass through pins 5 and 4.

Photographing Water Drops

August 5, 2013July 2, 2013 by Martyn

For quite a while I was looking at water drop photos and thinking about trying to do them myself. I finally gave it a go. My first try was simply making drops and trying to capture the splash. Everything was manual; the water drop, the shot, and it was very hit and miss. Mostly miss…

I did get some shots I liked but these are nothing compared to the shots from other people.

When researching online it quickly became apparent I wasn’t going to get better shots with the setup I had; which was a plastic bag with a small hole and hitting the shutter release like a maniac.