Help needed

Hi everyone
Does anybody know how to get this working:

The circuitry is an RS232 Optical Isolation which connect on Serial COM port.

**broken link removed**

How can I make an adapter to get this circuitry to work on USB?
Thanks

I am not sure what your problem is but lets start.

The device in the link is intended to make an electrically isolated connection between a PC serial port and some remote device which uses RS232. Also, something on the remote side must provide a 5volt supply to power the isolator.

As for using it with a USB device, the quick and simple way is to buy a USB to RS232 converter.
You could build your own USBto 232 converter but the process will be painfull and expensive.

Anything else?


JimB

Usb - Rs232

The problem is I want to build an USB - TTL data cable, optical isolated with the circuitry shown.
I have a schematics, I don't know if it works.

If it is as you say with USB adaptor, could I use a GSM data cable to adpt it to the optocouplers? I saw that the power in these cables is 3.3V, and I need 5V.If I can increase power to 5V, can I connect the optocoupler to the out of the GSM data cable? In my opinion, the GSM data cable creates a virtual COM port, is powered 3.3V, has the necessary drivers. The only problem are 3.3V->5V and the connection between the 2 circuitry, if is correct.

Thanks

OK lets go back to the beginning.

What are you trying to connect to?
I assume you have a PC with USB but no serial port, so you want to make a USB to RS232 (or is it TTL?) converter.
Then what are you going to connect to the converter?

JimB

USB connection

I am trying to connect a photo camera to PC. Camera signal is TTL. Camera connects only to serial port (DB9).
I want to use the optocouplers to isolate the connection. The point is to adapt somehow the USB to TTL, and use the optocouplers.
How else could I build an opto isolated data cable USB-TTL?
Thanks

samltd said:

I am trying to connect a photo camera to PC. Camera signal is TTL. Camera connects only to serial port (DB9).
I want to use the optocouplers to isolate the connection. The point is to adapt somehow the USB to TTL, and use the optocouplers.
How else could I build an opto isolated data cable USB-TTL?
Thanks

Click to expand...

But WHY do you want it opto-coupled?, it makes no sense?, there's no reason to want it isolated?.

Assuming you do, for some bizzarre reason?, it's a serial camera, use the serial isolator you've already mentioned above, feed that from a USB-Serial convertor, these are freely and cheaply available.

Or, more sensibly, just feed the camera directly from the USB-Serial convertor.

Adapter

Initially I built this level shifter. Can't connect straight to RS232 port, since uses TTL signals.
I wanted to isolate the connection, and I found this optocoupler. Now I'd like to connect thru USB port, not serial, keeping the optocoupler.
In what I've seen I have 2 options:
First, using a FT232 to build an USB - Serial adapter.
Second, using a GSM USB Data Cable, and to connect the optocouplers to that cable. I don't know if it works, since GSM cable has 3.3V, and the optocoupler uses 5V.
What do you think? Thanks