• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 78 subscribers
  • Views 1493 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Help with Launchpad EXP430G2 USB serial port

Tom Apalenek
Prodigy 20 points
Other Parts Discussed in Thread: MSP430G2553, ENERGIA

I've been trying to get the USB serial port on the Launchpad working for a while now with no success.  I have been reviewing all of the forum postings and any other internet information I can find.  But nothing has helped so far.

I am just trying to use the port to read back live data from an MSP430G2553 as a debugging aid.

This is where I am:

 - I am Using Windows 8.1 and have the CCS development suite loaded

- I have confirmed that the TI USB serial port driver is loaded.  Under Ports in Device Manager I see MSP430 Application UART (COM3). It shows "working properly" and I have the parameters set to 9600-N-8-1 with no flow control.

- I have a modified version of the UART echo character sample project loaded into the 2553 that just sends out upper and lower case A-Z in an infinite loop.  I have confirmed with a scope that I am getting serial data out of the TXD pin on the 2553.  The timing/character length looks about right for 9600 baud. One bit is about 104 uSec.

- I'm using a Rev 1.5 Launch pad and I've also confirmed with a scope that I'm seeing serial data at R6 - BRXDI on U1.

- I've opened the COM port in Putty and in the Terminal window in CCS.  I see nothing.  No characters, no garbage, just nothing.  In Putty, if I try typing characters I see nothing on the TXD side of U1.  If I set Putty for Local Echo I can see what I'm typing.  But nothing seems to be transmitting.
When I have the port open in the terminal window of CCS, if I try typing anything, CCS locks up completely and I have to close it.

I am out of ideas.  If anyone has any suggestions, I would greatly appreciate it.

Thanks,

Tom

  • 0
    Intellectual 965 points

    You didn't mention anything about flipping the RX/TX jumpers on the board to support the hardware serial on the 2553 so perhaps that could be the cause.  Please see the diagram below from the energia.nu website:   

  • 0 in reply to Dubnet
    Prodigy 20 points

    Thanks Dubnet.

    But, yes, I did switch the jumpers.  My confirmation that they are correct is the fact that I'm seeing the serial data from the 2553 on the BRXDI pin on U1 on the emulation side of the board.  I probed R6 - a 100 ohm resistor connected to the BRXDI pin on the chip and I can see what looks like 9600 baud serial data just fine.  So, even if I have baud rate, bits or something set wrong I should at least be seeing some garbage in the terminal window.  But I've triple checked all the serial port settings on both sides also.

    Really puzzling, and frustrating.

    Best,

    Tom

  • 0 in reply to Tom Apalenek
    Intellectual 965 points

    Have you tried using an OS other than Windows 8.x?  I seem to recall that some have had issues with the serial communications under Win8.  You could load Energia (energia.nu) on to a Win7 or XP box and use that as a test of the Launchpad itself. You may also want to try searching the website http://forum.43oh.com on the Windows 8 issue for a possible answer.

**Attention** This is a public forum