The Olympus E-520 uses a single 12-pin port for USB computer interface, video output, and remote shutter release. Thus, unless you have a combination cable, you can only use one of these functions at a time. Olympus does make a combination USB/video cable (that is ridiculously overpriced) but no other combinations. I wanted a combination video out/remote shutter release cable, so I made my own. I threw in the USB as well, as long as I was at it.
One thing you need to know before you embark on this project is that when the video cable is plugged into the camera (including this cable), the video feed to the camera LCD is disabled. This is so even if the video cable isn't plugged into anything. (I think this is why the video shield is connected to two USB pins - see below - the pin bridge acts as an video cable insert notification to the camera.) This means that it you want to use the multi-cable to run USB out and shutter cable release only, you will not be able to see anything on the camera LCD, either camera settings or shot review.
Here's what the finished cable looks like. I made a dongle-style cable because I didn't want to have long cables I wasn't using hanging off the camera. The dongles terminate in a RCA male, USB male and 1/8" stereo mini-jack (for the remote).
Before you get started, I have to point out a couple of things. First, you undertake this project AT YOUR OWN RISK. There may be mistakes in the pinouts I have provided, and maybe you could fry your camera, I don't know. You need to know how to use a multimeter, and you need to double check the pinouts against store-bought cables. The project requires some very fine soldering, this is NOT a project for the beginner.
OK. Here are the pinouts for the 12-pin connector Oly uses. The two unused pins are for audio out, since the E-520 does not record audio, we don't care about them.
We'll deal with the pinning of the internal connectors later.
The first thing we have to do is to get a 12-pin male connector. I have not been able to find a retail source for this, so we are going to have to get one by cannibalizing a store-bought cable. I got a $3 video cable off of eBay.
First thing to do is to cut all the way through the plug body near the bottom (I used a utility knife, the kind that takes the trapezoidal blades).
Take the piece you cut off and warm it up. I put in in the toaster over on "warm" for a while. This will soften the plastic cover a little (do NOT melt it). Then you should be able to pull off the metal plug, leaving the plug bare.
The plastic insulation is like dried hot glue. Trim and pull it off. You can cut into it and then grab pieces with needle nose pliers and pull them away. Here's the connector with the insulation removed.
You can see that the attachment pads are arranged in four rows of three, two rows on for each side of the connector (top and bottom). With the cable I bought, the pads that were not used for the cable were covered with plastic. I had to cut the plastic away with the utility knife to expose the pads. This is pretty small and fine work, you may want to use some magnification. Or you may be lucky and have a connector that has all the pads already exposed.
So here are the pinouts for the two sets of pads.
Soldering the wires to the pads is a lot easier if you tin the wires before hand. Here's the video cable wires tinned. Actually, since there are two pads for the video shield, I should have twisted the ground wire into two strands instead of one. As it was, I soldered the cable ground wire to pad 12 and then soldered a short bridge wire from pad 12 to pad 11.
Here are all of my cables tinned and prepped. If I had it to do all over again, I would have left the insulated length of wire outside the jackets a little longer, they ended up being almost to short when I was soldering the final attachments, and it doesn't matter if the individual insulated lengths of the wire are a little longer because we will stabilize them with hot glue after soldering.
To solder, start on the bottom row on one side, then do the top row on that side, then turn over and repeat. I found it helpful to trim the tinned bare ends of the wires to 1/16" or so and load the end with a little more solder. I have a cheap pencil soldering iron, I ground down the tip to make it finer.
OK, so here are all the wires soldered. I don't have photos of the soldering process. But if you need photos, or tips on soldering technique, you should not be trying this. The red tape was to hold the cables together for strain relief when I was soldering the last set of pads.
The next step is VERY IMPORTANT. Take your multimeter and test each connection. You need to make sure that for each contact point on the cable ends (1) you have a good circuit to the appropriate pin on the connector end and (2) there are no shorts (i.e., that that connector connects ONLY to the appropriate pin. You should be confirming that the the connections are the same as with your store-bought cables.
Now that we're satisfied the cable will not fry the beloved E-520 when its plugged in, we will insulate and stabilize the connected wires. Take a hot glue gun (on the "hot" setting) and inject hot glue into the spaces between the wires and spread glue on top of them (but not larger than the body of the connector. You can lick your fingers and use them to mould the glue into shape. The glue stabilizes and insulates the wires from each other, and provides strain relief for the soldered attachments.
Once the hot glue has cooled, slip a piece of heat shrink tubing down onto the cable assembly. You want a size that you can just slide over the plastic plug cover you removed at the beginning. Then warm the plastic plug cover so it gets flexible, and slide it over the plug end. I rubbed a little bit (a tiny tiny bit) of cooking oil on my fingers and then on the plug and hot glue to help it slide on.
Here's the cable assembly with the heat shrink tubing slid down the cables and the plug cover slid on the end.
Now take the hot glue gun and build up a collar around the exposed cables up to the edges of the plug cover. This gives a little more stabilization and a nice transition from the plug cover to the cables when the heat shrink tubing shrinks down.
Now slide the heat shrink tubing up onto the plug cover and warm it to shrink. I waved it around in the open toaster over set to broil.
The last picture is of my cable remote. It's a $12 eBay item. I cut the cord and attached to 1/8" stereo mini-plug/mini-jack.
Finally, here's the thing hanging off the back of the camera.