• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 32 subscribers
  • Views 889 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

RM42 Launchpad UART question

Andras Kapy
Prodigy 50 points


Hi, i'm working on a small project with RM42 Launchpad.

A sensor is connected through UART.  I connected the SCI_RX and SCI_TX pins to the sensor.

Do i need resistors for earch pins?

Are these pins tunneled through the XDS100v2 virtual COM port?

Thanks,

Andrew

  • 0
    TI__Guru 68980 points

    Hi Andrew,

    Yes the pins are tunneled through the XDS100v2 - see sheet 3 of the schematic pins 38/39 of the FT2232HL.

    There are series resistors 0 ohm on these pins - their purpose is so that you can remove them to break the connection to the FT2232HL and instead access the SCI pins on J1(booster pack) pins 3,4.

    I really can't answer your sensor / resistor questions.  You have to look at the spec of the sensor to determine this.

    If the sensor is an IC and it's UART pins are 3.3V LVCMOS compatible then you could connect directly.   If the sensor includes a line driver / transceiver then you likely need to add a matching transceiver to the launchpad to convert the signal levels back to 3.3V LVCMOS.

  • 0 in reply to Anthony F. Seely
    Prodigy 50 points

    Hi Anthony, thanks for the exhaustive answer. Right now we purchased an RM46 HDK. The problem is that we need 2 UART channels AND debug capability. Is RM46 HDK the right choice or do we need to change it to an RM57?

    Thanks,

    Andrew

  • 0 in reply to Andras Kapy
    TI__Guru 68980 points

    Andrew,

    The UART that is connected to the XDS100v2 is available for your use .. it appears as a windows virtual COM port when you plug the HDK in and it is not used for debugging the part.   Debug is separate from the COM port.

    If you need two physical UARTs i.e. you don't need one connected to your PC but you need 2 available on the expansion connectors to connect to some other hardware.   Then you can disconnect the UART from the XDS100v2 by removing 2 resistors in the HDK board and use the UART on the expansion header instead.

    So I don't think you need to upgrade to RM57 just to get an additional UART.

  • 0 in reply to Anthony F. Seely
    Prodigy 100 points

    Sorry for writing in this old post but I am facing up with a similar problem.

    EDIT: I finally solved it.

    Thanks,

    Agustí.