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.

LAUNCHXL-RM42: Problem with receiving data over UART SCI1_RX line

Part Number: LAUNCHXL-RM42
Other Parts Discussed in Thread: HALCOGEN

Hi,

I am having problem receiving data over UART on the LAUNCHXL-RM42 (rev C) board.

I've written code to simply echo back typed characters on a serial terminal. The code works when connected to the XDS100 USB serial COM port (USB cable from PC to LaunchPad board).  However, when tested on a different COM port (virtual COM port with FTDI USB to serial cable) on pins SCI1_TX, SCI1_RX, the receive line (SCI1_RX) does not get any interrupts from input characters.

I use HALCoGen (4.7.1) to configure the SCI module to enable the UART function:
 - On the Driver Enable tab, enable the SCI driver
 - On the SCI/LIN Globlal tab, enable RX INT (high level interrupt)
 - On the SCI/LIN Data Format tab, configure baudrate=9600, stop-bit=1, length=8
 - On the VIM Channel 0-31 tab, enable channel 13 for IRQ (LIN1 Level 0)

Please let me know if I've missed anything.

Thanks

  • Hi Tien,

    RM42 has only one SCI module. The SCI signal is connected to FTDI chip (U2) on RM42 Launchpad. If you want to use SCI signals on the header to communicate with another device, you need to remove R8 and R9, and connect SCITX and SCIRX to your device or board. 

  • Thank you for your answer.  Just a few clarifying questions:

    - What are the ramifications for making the suggested hardware change?

    - Will I be able to flash and debug firmware over the micro-USB port?

    - Will I need to use a different JTAG programmer/debugger to flash and debug firmware?

  • - What are the ramifications for making the suggested hardware change?

    You will not use the SCI from the Micro-USB

    - Will I be able to flash and debug firmware over the micro-USB port?
    - Will I need to use a different JTAG programmer/debugger to flash and debug firmware?

    it doesn't affect the JTAG and debugger.