632 Serial LCD with Third-Party USB/RS232 Adapter?!?

Corporate Dog

New member
I have the following connectors/adapters/equipment...

- CF 632 Serial LCD
- CF WR232Y09 Ribbon Cable
- CF WR232Y07 Serial Gender Changer
- A Third-Party USB/RS232 adapter, similar to the CF USB232A; the drivers for this device can be found here: http://www.orderlogistix.com/drivers/rs232/

The LCD itself works fine when I plug it into a serial port.

But when I try to plug it into a USB port using the above equipment, CrystalControl doesn't recognize it at all.

I suspect the problem is the USB/RS232 adapter, which I purchased (cheaply) on eBay, and which appears to be designed for use with HID devices. A recent Usenet post that I found, suggests that such adapters don't raise the line voltage properly (only one of the nine pins carries even a fraction of a volt, whereas a standard serial port would carry +12V/-12V on three of its nine pins).

Can anyone confirm that this is the problem? The 632 has its own external power connector, but does it use the voltage on the serial port for other purposes? Is the USB232A essentially the same adapter, or would it actually make a difference in this case?

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Last edited:

Corporate Dog

New member
And here's my answer, straight from the product decription page...

Low power: Non-backlight operation will self-power from the DTR and RTS lines of most serial ports.
Guess I'll be ordering the USB232A this morning...


CF Tech

You could request to return the module and have the "real" USB board added to it. That way the backlight would work.
USB LCD Displays - Graphic and Character LCDs with a Keypad