Serial Release Cable DIY

[watersblue]

Can someone help me out, please? I have tried to follow the guide for

making my own optoisolated shutter release cable, as outlined here: http://www.covingtoninnovations.com/dslr/canonrelease.html

I can't get the camera to communicate with my pc running windows xp. I purchased a cheap serial to usb cable from eBay, and don't know whether this is the problem or something else. The camera is connected via the regular Canon mini usb and this works with APT, up until anything a second or over in BULB mode (CANON 350D). I now have the DIY cable connected to the serial to usb, but I still can't get bulb exposures.

I am not sure which is PIN 1 on the opto isolator. I assume it's the one with the slight circular indentation above it.

My other problem is the serial to usb software that came with this cable; I am presented with these folders, but don't know which driver I should use:

Usb To Rs232 2303 WHQL

Usb To Rs232 (340) WHQL

Usb to Rs232(2303 includ 2 IC）

Is there some other driver I can download instead? Is my cable just too cheap and never going to work? And which is PIN 1?

Thanks for any advice you can give me. Steve

[watersblue]

By the way, this is the isolator:

http://www.ebay.co.uk/itm/EVERLIGHT-H11A4-OPTOCOUPLER-TRANSISTOR-O-P-DIP-/271177851513?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item3f2375a279

Here's the usb serial cable:

http://www.ebay.co.uk/itm/USB-2-0-to-RS232-Serial-Port-DB9-9-Pin-Male-Converter-Adapter-Cable-PDA-GPS-/180833984215?pt=UK_Computing_Parallel_Serial_PS_2&hash=item2a1a8b9ed7

[malc-c]

I've check the pin outs with the data sheet and they match OK - Pin 1 is normally indicated by a dot, or there may be a small U shaped marker in the casing indicating the top, in which case pin 1 is top left when this dip is uppermost.

That USB adapter could be the cause. It doesn't indicate what chip set it is, nor what TTL levels it uses. If its 3.3v than it might not be enough to activate the chip. True RS232 levels are +/- 9v. You would be better off using FTDI cable but get the TTL-232R-5V-WE version which works well as it uses 5v TTL levels

Cable and drivers can be found here http://www.ftdichip....SBTTLSerial.htm

Oh and I think you'll find the driver for your current cable in the Usb To Rs232 2303 WHQL folder - 2303 is a chipset manufactured by Prolific

[watersblue]

I've check the pin outs with the data sheet and they match OK - Pin 1 is normally indicated by a dot, or there may be a small U shaped marker in the casing indicating the top, in which case pin 1 is top left when this dip is uppermost.

That USB adapter could be the cause. It doesn't indicate what chip set it is, nor what TTL levels it uses. If its 3.3v than it might not be enough to activate the chip. True RS232 levels are +/- 9v. You would be better off using FTDI cable but get the TTL-232R-5V-WE version which works well as it uses 5v TTL levels

Cable and drivers can be found here http://www.ftdichip....SBTTLSerial.htm

Oh and I think you'll find the driver for your current cable in the Usb To Rs232 2303 WHQL folder - 2303 is a chipset manufactured by Prolific

thanks for that, malc. I'll try a better cable.

[Nordberg]

In case it helps, I bought one of these from eBay a couple of weeks ago:

http://www.ebay.co.uk/itm/320551669823?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

It comes with XP drivers (I use XP SP2 on a MacBook Pro) and it works a treat with my serial release cable, Canon 400D and Backyard EOS software.