Shop OBEX P1 Docs P2 Docs Learn Events
PC Serial Port Problem with IBM Laptop — Parallax Forums

PC Serial Port Problem with IBM Laptop

Harry StonerHarry Stoner Posts: 54
edited 2006-02-27 19:48 in BASIC Stamp
I searched the forum but didn't have much luck turning up hits.

I have a working BS2 hooked up to a laptop, communicating at 4800,N,2. This has been working flawlessly for 2 years. Now I am setting up a new laptop for new projects. I tried to use the new laptop with same code as the old laptop, but it would hang when trying to communicate with the BS2p over the serial port.

As far as I can tell, the PC code hangs sending the first byte.

I am not at liberty to program the BS2p. I would just like to know if there are any known problems with my laptop with respect the BS2p. The BS2p has a Sipex232 chip in front of it to convert serial to TTL voltages.

The laptop is an IBM T30 with a real serial port running Windows XP. I tried adjusting the COM1 parameters to match the working laptop. I set FIFO buffers to minimum and also tried disabling the UART option but no differences.

Shortly I will have an FTDI-based USB to serial adapter to test with and that may solve my problem.

FWIW the laptop works fine programming and running with another type of controller and environment, so I believe the port is fine.

Would the likely suspect be low RS232 voltage? I haven't measured it yet.

Thanks.

Harry

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-27 17:40
    Harry,

    ·· Setting the FIFO buffers to minimum doesn't usually work.· Unchecking the box "Use FIFO Buffers" is usually required.· And what UART did you disable?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Harry StonerHarry Stoner Posts: 54
    edited 2006-02-27 19:46
    Thanks Chris. Sorry, I wasn't clear. I didn't "disable the UART" but disabled "Use FIFO Buffers" as you suggested. That didn't work. On the laptop that works, "Use FIFO Buffers" is checked. But either way (checked or unchecked) didn't make a difference on the IBM laptop.

    Thanks again.

    Harry
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-27 19:48
    Could be the port, but I would check the more obvious things first such as low batteries or a bad connection/cable.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
Sign In or Register to comment.