EOS Remote Timer

This page describes my home made remote shutter timer which I have made to use with my Canon EOS 10D, but which should be easily adaptable for use with other cameras. If you decide to follow where I have been, you do so at your own risk. I simply don't want to know if you damage your cammera.

I found that the price of the canon remote timer (TC-80n3) rather too expensive for what it is, especially as it doesn't support some obvious features like mirror lock up and external trigger.

If you are going to use this with the newer EOS cameras like the 10D, the first thing you will need is a home made n3 plug

If not, or you already have one then the other thing you will need is a clue with electronics, especially PIC micro controllers. This timer is built around an 18lf452 running at 3V, though I will probably use an 18lf252 for the final cut. There is a Nokia cell phone display for programming the thing, and also 4 buttons - UP, DOWN, ENTER/SELECT and START/STOP. The unit produces 2 output signals, both active low to drive the camera - shutter release and focus (to wake the camera up).

Here is a flowchart which describes how the timer functions when it is running. There is an external trigger signal, then a timer (from 0s to 99h59m59s) then the shutter is released. The shutter time can be set to 0s (actually 0.2s) to 9m59s. After this there is an optional pause (0 to 59s) and interval (0 to 99h59m59s) timer. You can set the number of shots per cycle (0 to 9) and the number of cycles (0 to 99). If the initial timer or interval timer are longer than 2 minutes, then the focus output is pulsed for 2s to wake the camera up, 30s before the shot is to be taken. If mirror lockup is selected then the shutter output is pulsed 2s before the shot is taken (there is actually a 2s extra delay).

The timer code is written in C, built with Microchip C18, and executes as a finite state machine, using timer0 to produce a tick.

This is a photograph of the prototype hardware, built on my breadboard.

Here is a circuit diagram of the prototype hardware.

Here is a zip file with all the source code to date and the built hex file ready for programming a 18f452. It's worth saying that this is alpha code and might not work properly yet. It might ever only get released as beta code, and only then if I ever finish the thing!

Any further work on this project will be published here.

I have just made a partial update, which has moved some connections arround prior to changing the chip to a 18F252. The source code is still built for an 18F452, but the circuit shows the connections for an 18F252. Also the picture of the prototype is missing. Sorry about this, I will sort all this out when I build the thing on veroboard with an 18F252 which will be not very soon.

You are welcome to eamil me with any comments if you like at mike at spikey-mike.com.

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