Time Lapse Photography
How to turn a TI-86 into an Intervalometer
For some time, I've wanted to do a little time lapse photography. Very high end cameras have time lapse features built into the software. Some low end cameras do too; however, our Canon XTi doesn't. The only way to take time lapse pictures with the Rebel series is to rig an intervalometer yourself.
There are many ways to create an intervalometer, but this method doesn't require any soldering.
Parts:
TI-86
Canon XTi
2.5 mm double ended cable
tape
paper for labels
Tools:
Wire strippers/cutters
Write the Program
Disp "Interval in seconds"The program asks for a number. With full batteries, an input of 450 takes a picture every 3 seconds. It will be slower if the batteries are worn out.
Disp "x 100"
Prompt A
While 1
For(H,1,A,1)
End
Outpt("CBLSEND",A)
End
Alter the Cable
The XTi has a 2.5mm remote input that is simple. The 2.5mm plug has three sections. Shorting the middle section with the base makes the camera focus, and shorting all three makes the camera take a picture.
The TI series graphing calculators also use 2.5mm jacks for their communication port. Someone wrote a program using the TI-89 as an intervalometer. Someone else wrote one for the TI-83. I combined a little of each in order to get the TI-86 working.
This will create a one-way cable. Using the cable in reverse will not work.
Label one 2.5mm jack as the Camera side. Label the other side as the TI-86 side. Cut the cable in half and strip the wires to expose about 3/8" of bare wire on each side.
Combine the red and white wires from the camera side with the red wire from the calculator side. Simply cut off the white wire from the calculator side--it will not be used. Connect the ground wires from each side.
All that's left to do is start the program and connect the camera to the calculator with our new cable.
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5 comments:
Wow nice hack. One of the reasons I purchased a lower end Cannon was
CHDK that allows this kind of thing.
Thank you, thank you, thank you!
I've been trying to get this to work since I first heard about it, but kept getting stuck with the focus issue. Now I don't have to shell out $50 for a used TI-83 or 89. You rock!
Instead of Outpt("CBLSEND", A), you can use Send(A) if that function is available on your calculator. The TI-85 doesn't have it in firmware less than version 9, the 86 should have it.
Also, for a Rebel XSi, no cable modification is necessary - just make sure you put it in manual focus mode!
so i tried this program in my ti-83 plus and the only change i had to make was the "output( "cblsend", A)" changed to "send(A)"... WORKS GREAT!!
I'm getting the camera to focus every three seconds but it won't trigger the shutter!? I have the xsi and jon said no cable modification is needed...any ideas? I'm soo close!
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