Problem connecting with BSII Rev. A

Todd Swift

Hi there,
I've got an older BSII Rev. A that I'm trying to get connected to a laptop computer. I did have it working several years ago on a DOS machine. Some relevant points:
- I'm not using the USB-serial converter reccomended by Parallax at this point
- I have tried two brands of USB-serial converters and have tried on a desktop directly to a serial port
- In all cases, the software ocaissionally recongnizes the stamp, but most of the time will not. I'm sure I have the correct com port, and the softare will identify loopback and echo on the correct port. One student group did say they got a program downloaded and an LED blinking one time.

This has happened on at least three different computers. At first I thought it was the USB-serial issue, but I'm starting to think it's the Stamp. I have checked the voltage regulator and the output is fine. Has anyone had this experience? Is there a more detailed troubleshooting document out there? Thanks for any help!

Sincerely,
Todd Swift
Loras College
Dubuque, IA

Jon Williams

I don't believe it's the BASIC Stamp -- if you had it working before, then it is working. What's changed is your connection; you went from serial to USB. There is a dramatic difference between USB-Serial converter, and we went through a lot of painful experimentation to find something that would work consistantly (FTDI).

If you don't want to use the FTDI adapter, you may want to reduce your com port IO buffers to their minimum settings. Also, putting a DEBUG statement in your programs will hold the serial port open, and may help (we've seen this issue with a lot of laptops that use NON-STANDARD serial ports).

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Jon Williams
Applications Engineer, Parallax
Dallas Office