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/

Problems with Solmeta GPS N1 for D7000

It has been eight months since I last used the Solmeta GPS N1 unit.  I thought I did something wrong back then, but I don't think so now.  The unit is fairly simple to use.  You just plug in the provided USB cable and power on the GPS unit to start receiving GPS signals.  In my test last night, I did not even power on the GPS unit and yet, after a few shots, three things failed to work on my D7000:

1. Half-pressing the shutter button to focus actually triggers the shutter.
2. Sometimes, the shutter release button stops working.
3. The Play button to review photos taken stops working.
4. The Menu button stops working.

The only way to restore functionality to the D7000 is to disconnect the USB cable.

Having observed the behaviour of the SB-25 flash gun when it is triggered with a PC Sync cable, I have a feeling that some wires inside the Solmeta unit get shorted (to activate the camera shutter) and not released.  To trigger the SB-25 flash gun to fire off, the two wires of the PC Sync cable just need to be connected together.  The SB-25 flash gun will fire off once.  If the two wires stay connected together, the flash gun will freeze up, i.e. the menu and function buttons will stop working.  A very similar behaviour is noticed here with the D7000 and the Solmeta unit.  I wonder if the trigger wires got shorted and not released, electronically.

I should have done this test last July when I bought the unit.  Well, it is still under warranty so I just e-mailed service[at]solmeta.com for support.  Let's see what they say.

Solmeta GPS N1 for D7000, part 2

The GPS unit arrived on August 11, a couple of days before a BBQ.  It took under two weeks to arrive, faster than I expected.  The parcel was not shipped through China mail though.  It was through the Hong Kong post office.  Parcels do arrive in Canada faster when they are shipped out of Hong Kong.

Anyway, I got to play with the Solmeta for the first time yesterday at the BBQ event.  It was simple to use.  Just slide the main unit into the hotshoe flash mount, connect the USB cable to the unit, and connect the USB cable to the camera.  Now, interestingly, contrary to what I have read online, the USB end that connects to the camera is not so easily breakable.  It fits in very tightly.  I really have to apply a good amount force to plug it in and to pull it out--if the connector head is wet, it would be next to impossible to pull it out.

Once the GPS unit is connected up and turned on, it takes about a couple of minutes--I did not time it but it felt like a couple of minutes--to acquire satellite signals.  The LED at the top would blink as it tries to acquire signal, until it becomes solid when it is ready.  While the GPS unit is connected to the camera and is turned on, the top LCD on the D7000 displays "GPS"  beside the focus mode indicator.

When it is all ready to go, you just shoot and GPS information is recorded with the photo.  To view the GPS information, I would scroll through the photo detail screen as usual.  GPS information was now displayed along with the histogram, ISO, aperture, speed, etc.

Now, there was one annoying behaviour I observed but have not been able to reproduce after I returned home.  At the BBQ, with the GPS unit connected to the D7000, I was able to shoot like normal but then after a few shots, I was unable to half-press the shutter release button to focus.  As soon as I half-pressed the button, the camera took the shot right away so the pictures came out blurry.  Was it a problem with the GPS unit or with my possibly broken Nikkor 18-200mm lens?  To troubleshoot, I just removed the GPS unit and the shutter release button worked again as expected.  Something is funny about this GPS unit ... it could be because the USB cable was not fully inserted.

In the photo above, the camera fired away before the lens had a chance to focus as if it was shooting in manual mode.  This is a behaviour I have yet to reproduce.

Solmeta GPS N1 for D7000

I decided I was not going to buy the PC-Mobile version after wall.  I decided instead to purchase a Solmeta GPS N1 unit for my D7000.  (It costed me $111 USD with free shipping, so I guess the unit is about $100 USD or so.)  The main reason for the Solmeta is the built-in battery.  While the other brands claim very low power draw, the built-in rechargeable battery of the Solmeta unit will power the GPS unit for up to 10 hours before it has to draw power from the camera.

When you order the unit from this eBay seller I bought it from, you need to specify the camera you are purchasing the GPS unit for.  They will then provide the right cable for that specific camera.  Hopefully, they will not send me a cable for another camera by mistake.

As you can see from the picture, there is a cable that fits the D7000--the CA7000.  This L-shape cable will not work well with the D90 but I figure I will be shooting with the D7000 most of the time.  If I do need to use the GPS unit for the D90, I would have to dangle the GPS unit off the strap eye socket on the camera.

This eBay seller offers a "free" gift--car charger or "wall plug" so the GPS unit can be recharged outside the camera.  I think it should not be a free gift.  It should be bundled with the package!  How else are you supposed to recharge the battery?  I chose the "wall plug" as I already have a car charger-to-AC adapter (I think).

Now, it's a 3-4 week wait.  It takes that long for shipment from China to arrive here in Canada.  Incredible.