USB serial adapter / laptop problems...

circuituity

We just purchased the BS1 w/board and cannot get the laptop to recognize the stamp. Everything works fine via serial coms on a desktop system.· We have isolated the problems down to a Belkin model f5u409 USB to serial adapter and/or its software.· The link light on the adatper remains on during a download attempt but the rx light stays lit for an unually long time. We have tried the same scheme on different pc's (both desktop and laptop) with the same results.· Any ideas regarding this problem will be greatly appreciated as we need to use our laptops with usb ports·to implement program changes in the lab and field.

Thanks All,
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Mike Green

Some USB to serial adapters do not work for programming a Stamp. Some work when the Windows driver parameters are changed. There's a Parallax document on this: www.parallax.com/Portals/0/Downloads/docs/prod/ftdi/USBDriverTroubleshooting-V1.0.pdf.

Part of the problem is that many USB to serial adapters don't implement the handshaking lines or only implement some of them and often not the ones that the Stamps need for programming. Another problem is that the download timing is very exacting and some adapters have delays that are ok for garden variety serial I/O, but cause downloading to fail.

Adapters that use the FTDI chipset are known to work and Parallax uses that chipset for its own adapters. I have also used Keyspan's High Speed Serial Adapter.

LilDi

Dave Andreae mentioned the Belkin adaptor does not work with the basic Stamp.

http://forums.parallax.com/showthread.php?p=784398


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