Canon remote cable

[malc-c]

Hi,

Has anyone built their own serial remote shutter cable. I've found one site that recommends using an opto-isolator, which I'm looking at building

But wondered if anyone has any advice on this - I wouldn't want to muck up my newly acquired 400D

[Photosbykev]

The opto will protect the camera from any spikes and Covington is well respected so I wouldn't having a problem using it.

[Psychobilly]

That's the one I always use... build it "dead-bug" inside a 9 way D shell...

[malc-c]

Thanks guys for the feedback. I've just come across a variant which claims to offer better protection, so might go with this

Note the 1N4148 diode positioned to protect the opto-isolator and LED against the serial RS232 -12v 'Lo' voltages. Other designs seen on the web place the diode between pin 1 & 2 of the opto-isolator, and whilst this may protect the opto-isolator from any negative voltages, it also means that the laptop battery will drain via R2 during the hours when the serial ports RTS is 'Lo' (as well as placing -12v across the LED via R1, and potentially blowing it).

[StevieDvd]

I chickened out of the build and ordered one off of the bay.

[Psychobilly]

hmmmm but which circuit did they use

I wouldnt be too bothered about draining the laptop battery via the Diode and a 2K2 resistor...

[JKB]

Well I built one no prob, as per previous instructions. Only difference was the N3 plug for the 30D as opposed to the 3.5 jack. Works a treat.

Only difficulty I had was getting a single Optoisolator. Had to buy a 14pin Quad!

Finished product HERE

Cheers

[malc-c]

Just finished mine (will post pics later). I used the schematic in post #4 but noted that the pinouts were different compared to the one in post #1 for the 4N25. When I used pins 4 & 5 it worked fine

I used a small bit of strip board as I ended up braking the legs off 2 x 4N25's when dead bug building.. I had to remove some of the mouldings in the housing for stripboard to fit and thus superglue the two halves of the housing together, but it's still fairly neat.

I also picked up a 5m USB cable so made the remote cable approx the same length less the length of the USB to serial adapter, so now I can be a suitable distance from the scope to avoid vibrations when doing long exposures

Really chuffed with what the Canon 400D has to offer, and now just need some nice clear dark skies over the weekend to try this out

[Glider]

I use the design in post #1 with Canon 350D, 1000D and APT no problem.

[yesyes]

How did I miss this thread???

The circuit in your first post is exactly what I used in my "EOSbox"

http://stargazerslounge.com/diy-astronomer/137096-eosbox.html

Works fine with one little problem. You need to plug in the shutter cable to the camera AFTER switching it on and connecting the camera to APT. If you plug it in before, the camera will start taking exposures as soon as it is switched on. There is a solution to this but I have not tried it. I think I'll just live with the fact that I have to connect this up in a certain order...