Triggering the D7000

The reason I took out the Solmeta GPS unit last night was because I needed a way to remote release the D7000 shutter.  I thought the D7000 came with a PC Sync port like the D300.  It does not.  Instead of the PC Sync port, there is a special GPS port (see below).  The good thing with the Solmeta GPS unit is that it has a pass-through remote trigger 2.5mm stereo jack.  For my DIY, I just needed to build a cable with a 2.5mm stereo connector that goes from my laser/sound/lightning trigger circuit to the 2.5mm stereo jack.

Left side of Solmeta GPS N1 with 2.5mm jack and special USB port.

The D7000 / D90 GPS connector:

http://www.doc-diy.net/photo/remote_pinout/d90_pinout.jpg

The 2.5mm stereo connector to connect to the Solmeta has the same pin-out as the Canon plug except that to trigger the shutter, it is not sufficient to connect the tip (shutter) to the sleeve (ground).  To actually trigger the shutter on the D7000, I had to connect the ring (focus) to the sleeve (ground) first, then join the tip (shutter) to the pair.

http://www.doc-diy.net/photo/remote_pinout/canon_pinout.png

I fashioned a cable with a 2.5mm plug end from an old earphone.  I cut one end of the earphone, soldered three wires to it, and taped it together:

2.5mm connector with the Solmeta GPS N1.

Below is how I would connect to a lightning trigger circuit.  The three wires are isolated from one another until the OptoIsolator is activated.  This circuit is based on the laser trigger circuit with the resistor-capacitor components removed and switching the PhotoResistor and the 62 KOhm resistor around ... and ORgate1 should probably be removed.  The lightning trigger circuit activates the camera shutter when the PhotoResistor senses the flash from a lightning bolt.

Lightning trigger circuit

Reference:  The pin-out diagrams of the GPS plugs came from http://www.doc-diy.net/photo/remote_pinout/

Lightning trigger circuit

Toronto does not get much lightning and when we do, I rarely see them.  A few years ago, I did capture two lightning bolts through the window of my second story bedroom.  It was great.  I simply left the shutter open for 10 seconds at a time and I was lucky enough to catch two strikes.

Now that I have built the laser trigger circuit, I think my next attempt to capture lightning will depend less on luck and more on technology.  I can modify the circuit by switching the PhotoResistor and the 62 KOhm resistor around, and remove the DelayCapacitor for an instant trigger.  The circuit would be connected to the PC Sync port of a camera instead of the flash gun.  I tested the new circuit under normal room lighting by running an LED flash light quickly across the photoresistor.  The flash light was strong enough to trigger the circuit.

We are in the middle of a warm and wet winter.  Maybe there is a tiny small chance of a lightning storm?

Laser trigger circuit.  Switching the 62 KOhm resistor and the PhotoResistor around, and removing the DelayCapacitor should turn this circuit into a lightning detector, I hope.