Time Lapse Intervalometer for SLRs With 555 Timer IC





Introduction: Time Lapse Intervalometer for SLRs With 555 Timer IC

This instructable started with my previous camera hack making a remote shutter release. I found a 555 timer tutorial and realized how great it would be to automate my pictures and do some time lapse photography. I'm not too great with making electronics from scratch, so my friend Michelle helped out a lot with the planning of the schematic.

I found a great guide to time lapse photography that covers all the details before and after this Instructable. They mention the use of an "intervalometer" (a new word to me) which can cost $60 to $150 dollars. That's way too expensive for the casual photographer I think. So I made my own!

Step 1: Planning, Schematic, Materials

Below is a schematic that I made with free schematic software from ExpressPCB. You can also download the .sch file if you want to edit it. Remember, that won't get you a PCB to burn, only a schematic to mess around with.
Here's what this circuit will do. When you turn it on, the camera will get a false signal and take a picture. Then the big capacitor will slowly fill with charge while the green LED is on. How slowly is chosen by the variable resistor. When the cap discharges, the 555 outputs a signal to the transistor which connects the shutter control to ground. The red LED lights up and the camera takes a picture

There are also buttons to use the box as a remote shutter release when the circuit is off.

As you can see you need some stuff. Here's a list:

Resistors: 100k, 470k, 33k, and one 1M variable
Capacitors: 220µF, 0.1µF
LED's: Green, Red
Transistors: NPN-type switching
555 IC timer chip
IC holder socket (to switch out a bad chip)
Protoboard and then later a Radioshack IC PC Board
9V battery
On/Off switch
Momentary buttons,
Battery clip
For Pentax DSLRs, Canon Rebel's, and maybe some others:
Cell phone headset with 3/32" 3 conductor plug (make sure it works, but go cheap)
Extra wires
Project box
Soldering and wire stripping tools and such

555IC: $1.69
IC PC Board: $2.49
Handsfree headset kit: ~$5
Other bits and bobs: ~$10
So it all can be had for under $20 and some effort.

Step 2: Prototyping

This is where you need a protoboard (breadoard.) Michelle hooked me up with one and I'm thankful for it. The plugging in of things shouldn't be hard if you know how a protoboard works. If not go here.

The tricky part here is attaching the plug for the camera. When you crack open the microphone on your headset, you should see a tiny board like the one below. Your model may vary, but they usually have 3 wires. Those wires control the shutter and focus on your camera. Plug it in to your camera to find out which one is ground, which is focus, and which is shutter. This will be important later, so mark then, or write down which color is which.

When it's time to attach the headset wires to the board, you're going to need to attach them to some stronger wire. If they came coated with blue or red, they will be hard to solder, but persevere with lots of heat, abrasion, and patience and they will connect. Double check the wires work as expected with your camera.

Step 3: Testing

Before you go a ruin a perfectly good board (like I did) test it out.
The set of resistors and capacitors in this set up can provide an interval of 30s to almost 2m depending on where the variable resistor is turned to. Set up your camera and prototype and shoot some time lapse.
Keep in mind that a power adapter for your camera will be a big help in the future when you want to capture a whole day in time lapse, but batteries will work for now.
Below is my first attempt with the prototype.

Step 4: Final Build

Here you will make your awesome portable intervalometer. The radioshack IC board is perfect because it's already spaced out for an IC and has lots of copper solder points. I included a plan to fit the schematic onto this particular board. Connect the 9V an Ground anywhere they are marked.
The buttons are attached to the shutter and focus for some added functionality.
Then you need to drill some holes, solder some wires, and close it up tight.

Easier said then done I know, so here are some tips:
Draw lines on the non-copper side of the board so you can easily connect things correctly
Place your components on the non-copper side so your leads will be easy to solder.
Make sure everything fits before you drill and wire it up.
Tie a knot in the headset cord so you can keep it anchored inside your box.
Use shrink tube and/or tape to over exposed wires
Use as little wire inside as you can stand. It gets real crowded in there.

Step 5: Final Test and Limitations

Look it works!

Ice melting is boring, so I made sure it was a quick frame rate.
What can you use this for?

Ok, so you get what you pay for sometimes. If you went with a manufactured intervalometer, you would get a accurate interval setting. This isn't quite so accurate unless you put a knob on it or something. There is also another slight problem. The camera counts away or a desired length, the "off" time, and then fires off the shutter, the "on" time. It seems that this "on" time can sometimes be too short for the camera to register. Because of this, it sometimes misses pictures. As long as this happens not too often, no big deal I guess. There has to be a solution to this in the circuit that can extend the output pulse, but it's way over my head. I welcome your help on this problem.
Also the buttons don't work while the circuit is on. It would be nice to focus or take extra pictures while the timer is running. Any ideas on that are welcome too.



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    I've made this intervalometer, but problem is that my camera has to focus first, then fire the shutter. Therefore, I need two outputs; one for focus and second for shutter. Does anyone know how to make this with 555 timer(s)?

    very nice circuit.
    For those who would like to play with LM555 IC as a timer take a look at

    Corrected circuit diagram. Note polarity of 220µF capacitor. Current limiting resistors for each LED changed from 470K to 470Ω, 1/4W. Wiper of potentiometer connected to end terminal so that it works as a variable resistor.


    I've been looking at your circuit diagram, trying to use it as a starting point to understand the operation of the 555. I've also looked at the "standard" 555 astable circuit, and I have a few questions.

    I noticed you didn't follow the "standard" astable 555 timer circuit (http://www.eleinmec.com/article.asp?3). Is this because of the allowable values for R1, R2, and C? If not, wouldn't it be simpler to go with the standard circuit with a very large capacitor value and a properly selected R2?

    By the way, wouldn't it also be easier to guarantee an activation pulse of >20ms as suggested by tyler below simply by changing the values of the second (reset) pair of RC?

    I'm still reading up on this stuff, so please let me know if I'm wrong.


    Two more questions: isn't 470k a rather extreme value for the LED current limiting resistors? 470 Ohms would seem a more appropriate value.

    Assuming 20 mA current through the LED with a 9V supply and 1V drop across the diode, the current limiting resistor should be 400Ω. Either 430Ω or 470Ω, ±5%, 1/4W would be good choices.

    Yeah, I don't know too much about this. Do you have a better layout to share?


    Yes, in fact, I do. Thanks for your Instructable, by the way; seeing it in Make Magazine way back when got me interested in electronics.

    Here is my take on your circuit. It uses the 555 the way God intended, in the standard astable configuration. The "on" time is determined strictly by the values of C2 and R1, using the formulas given in the link in my first comment (in this case 0.15s) so there is little chance of missed shots. The wait time is determined by the values of R1, R2, C2, and the variable resistor R3, so the max value can be modified by using different resistor values.


    The entire lower half can be ignored, it is a driver for the red/green bicolor LED from Radio Shack to indicate power on (red) and timer pulse (green). Other arrangements would have to be made if using a different LED, or a pair of LEDs. (Note that the diodes in the LED driver are zener diodes, intended to be used "backwards".) I used a standard audio mini jack so you can just use an mini audio cable instead of having to hack up a cell phone head set.

    I eventually got so far as to design and etch a small single sided board to implement this circuit using SMD parts. It all works great. I have the board available in Eagle format if anyone wants it.

    That's awesome. Personally I would insist on the head set 3/32 jack because that plug fits in Pentax and Canon DSLRs. Maybe leave space for a standard jack to be soldered on or wires. Could we add momentary buttons that allow the focus and shutter functions to be triggered with out the 555? I find that helpful when setting up a time lapse.
    SMD is cool too. I'd prefer simple separate LEds for on/off too.
    What do you think?