Tag Archives: remote

Maker Wedding: XBee remote relay as photobooth RF camera trigger

XBee Button Relay Photo Trigger RF

If I didn’t have XBee’s kicking around from some other fanciful endeavour I probably would’ve purchased an inexpensive Aputure remote trigger for the photobooth at my wedding reception — but instead I decided to make an RF camera trigger system from parts I had around, mainly two XBees and a relay. XBee’s are great little wireless mesh transmitter/receivers, much like Tomax and Xamot what you do to one is instantly reflected by the other, so you need only connect a pin to high on the transmitting XBee and the same pin on the receiving XBee will go high — perfect for remotely triggering a relay.

crimson twins

The plan was to have one XBee with a simple pull-down button which would trigger a relay on the receiving XBee and whaddya know — it worked. The receiver relay was attached to a wired camera remote (Canon TC-80N3) I already had from a previous project which allowed the relay to trigger both a Canon Rebel XT and, after splicing in the original connector, a Canon 5D Mark II.
XBee Button Relay Photo Trigger RF
With this setup, two AA batteries for both the transmitter and receiver lasted for days. The only issue I found was that the Rebel XT needed about a 500 millisecond signal whereas the 5D Mark II would trigger instantly on a contact of any duration, I thought about a capacitor, timed-delay relay or 555 solution to keep the relay open longer, but never got around to implementing any solution — after all the 5D would capture the shot if not both cameras.

To be honest, this project survived to the night before, but I decided to scrap the photobooth entirely from the wedding reception to reduce complexity — the lighting turned out to be insufficient and, as the groom, I had no time left to deal with the camera setup. That being said, the theory is sound and it worked quite well for days in my living room, taking shot after shot of me and my fiancée lounging on our couch.


Converting the Canon TC-80N3 for use with the Rebel XT (and others)

After having fun with some infrared and macro photography I wanted to try some time lapse. Some cameras have built in intervalometers ( big word for interval timers ) which allow you to do time lapse with little effort. Sadly the Canon Rebel XT does not, so I searched around for solutions, most of which are quite expensive.

I found out some useful information:

  • the Rebel XT has a 2.5mm stereo jack connection for remote operation
  • connecting the ring and base of this jack trigger the autofocus
  • connecting the tip and base of the jack triggers the shutter

With this information I hacked together a makeshift solution with a 12v relay, 12v wall adapter and an X10 appliance module. This system sucked and wasn’t portable, but it was all junk I had laying around. Anyhow, I went back to searching and found out about the TC-80N3, a Canon wired remote which does all sorts of fun timer stuff, including time lapse and goes for under $100 on eBay now and then. Unfortunately it doesn’t work with the Rebel XT, the connector is different, out of the box at least.

I found out that it has three leads on the connector, as the Rebel does, so perhaps they function the same? It seemed to be the case so I went and purchased one, hoping to just swap the connector out.

Once it arrived I went straight to hacking it up. Chopped off the old connector, found out that there are two wires and a ground wire, sweet. With the help of my multimeter I determined that the red wire is the shutter and the white wire is the focus. So, to attach the new connector:

  • solder the red wire to the tip of the 2.5mm jack
  • solder the white wire to the ring of the 2.5mm jack
  • solder the ground to the base of the 2.5mm jack

Slip the cover back on or tape up the connector, whatever, and it’s all done. The Canon TC-80N3 modified to connect to and control a Canon Rebel XT. Doesn’t need much know how at all to pull this off.