So what do you want to do if you want to make time-lapse videos? You can buy a commercial intervalometer (yeah, right). You can check out some instructables like this one and make one yourself out of electronic components.

But what if you don't have the time/skills necessary to build one? You just want something quick and cheap.

Well, you can actually use a common TI graphing calculator (I don't know of any high school student without one of these) and hook it up to any camera with a remote shutter release socket. It's quite easy, and depending on your camera can require no electronic work at all.

**Signing Up**

## Step 1: Parts Needed

**A TI graphing calculator**- I'm using the TI-83+. I haven't tested my code on any other model, so I can't guarantee it will work.

**Camera with remote shutter release socket**- I'm using the Canon EOS Rebel. This has a 2.5mm socket that you can use to connect to the calculator. If your camera does not have a 2.5mm shutter release socket, you will need to create some sort of link cable that can connect the two together.

**Link Cable**- If your camera has a 2.5mm socket, you can use the link cable that should come with your calculator.

Hello

I'm French and I don't speak very well english but I'm going to try...

What

Y-1 % Y

While Y>0

Y-1%Y

does it mean ?

For the 84+ you can use the clock function to do this, like so:

Disp "START DELAY IN"

Disp "SECONDS"

Prompt D

D*652.73->W

Disp "HOW OFTEN IN"

Disp "SECONDS

Prompt P

Disp "HOW MANY SHOTS"

Prompt N

0->C

For(H,1,W,1)

End

startTmr->T

While 1

Repeat T=startTmr-P

End

startTmr->T

Send(D)

C+1->C

Output(8,1,"SHOT COUNT:

Output(8,13,C

If N=C

Stop

End

Thanks ahead of time.

I'm about to use it again for a new plane. Helps a lot with illustrating construction techniques for new students.

For(H,1,A,1)

What is H? And if someone has previously set H to represent a number, would it mess up the program?

If you are interested give it a try..

( the % are supposed to be arrows.. the STO key above on/off)

.................................................................................

Disp "START DELAY IN"

Disp" SECONDS"

Prompt A

A*333.3333 % W

Disp "HOW OFTEN IN"

Disp "SECONDS"

Prompt B

B*333.3333 % X

Disp "HOW MANY SHOTS"

Prompt Y

For(H,1,W,1)

End

Send(A)

Y-1 % Y

While Y>0

Y-1%Y

For(H,1,X,1)

End

Send(A)

End

...............................................................................

As you can see from what "solupine" showed.. you need to multiply your delay (seconds) by approx. 333.3333 to get the camera to fire at the right time...

The first delay , is how long till it takes the first shot.

The second delay, is how often between shots

This was done on a TI-83+ , if you try it on other models post it up if it works or not please..

flawlessly(so far). Thanks to instructables, I've built an intervalometer and a shutter release for less than$20! (Calculator doesn't count :P)to understand it the best i suggest putting it in as i have it above and running it .. it will explain itself..

I my self do not have the spare time anymore to reprogram it to see if i can get it to work. if anyone out there has any ideas on how to program it please feel free to post it.

Used my Ti-83 and Canon 1000d ( Rebel XS)

Bumping from below------------------

From Luberack (Mar. 10, 2011)

I also used silentfallen's program below. Very nice! I did notice that the timing seemed to be a bit off, so I ran the program at various times in front of a stopwatch. I put the numbers in Excel and got the slope of the linear trendline that tightened up the timing tremendously. Here's the scale factors you should use for the TI-84 Plus (not sure about others):

[note: "%" should be replaced by pressing the "STO>" button.]

A*750.64 % W

B*750.64-704.12 % X

So here's what the whole program will look like:

.................................................................................

Disp "START DELAY IN"

Disp" SECONDS"

Prompt A

A*750.64 % W

Disp "HOW OFTEN IN"

Disp "SECONDS"

Prompt B

B*750.64-704.12 % X

Disp "HOW MANY SHOTS"

Prompt Y

For(H,1,W,1)

End

Send(A)

Y-1 % Y

While Y>0

Y-1%Y

For(H,1,X,1)

End

Send(A)

End

...............................................................................

hit "QUIT" to save and exit programming

1) Turn on your graphing calculator (duh)

2) Press the PRGM key

3) Press the Right arrow twice to highlight the tab at the top titled "New"

4) Press ENTER

5) Enter in a name (I used "Camera")

In the step 6) I Pressed program, but does not appear Prompt . Can anybody Help me.

Thanks,

R.Gil

H and A mean?

Thanks,

R. Gil

I had modify the cable to make it a "cross over" cable. Assuming Tip is #1, Middle is #2 and Base is #3:

1 2 3

X |

1 2 3

So, Tip "crosses over " and connects to the Middle on either side. Base remains a direct connection.

Camera also has to be in Manual Focus mode (usually a switch on the lens).

Otherwise, when triggered the camera will only "half press" the shutter. So you'll hear it autofocusing, but not releasing the shutter. Using the Cross Over Cable and the Manual Focus fixed the problem.

I also used silentfallen's program below. Very nice! I did notice that the timing seemed to be a bit off, so I ran the program at various times in front of a stopwatch. I put the numbers in Excel and got the slope of the linear trendline that tightened up the timing tremendously. Here's the scale factors you should use for the TI-84 Plus (not sure about others):

[note: "%" should be replaced by pressing the "STO>" button.]

A*750.64 % W

B*750.64-704.12 % X

So here's what the whole program will look like:

.................................................................................

Disp "START DELAY IN"

Disp" SECONDS"

Prompt A

A*750.64 % W

Disp "HOW OFTEN IN"

Disp "SECONDS"

Prompt B

B*750.64-704.12 % X

Disp "HOW MANY SHOTS"

Prompt Y

For(H,1,W,1)

End

Send(A)

Y-1 % Y

While Y>0

Y-1%Y

For(H,1,X,1)

End

Send(A)

End

...............................................................................

hit "QUIT" to save and exit programming.