Wireless Serial Port

TruConnect provides a wireless link between your device(s) and/or a PC or mobile device.

This application note demonstrates using a Bobcat module as a wireless serial port, streaming data in and out via the BLE wireless interface. The demonstration uses two Wahoo evaluation boards.

Features Demonstrated

  • Serial Interface Stream Mode
  • Advertising to other Bluetooth devices (adv command)
  • Scanning for other Bluetooth devices (scan command)
  • Connecting to another BLE device (con command)

Setting up the Modules

  • Plug each of the AMS001-E01 Wahoo boards into a separate USB port on a computer. The USB interface provides power and a serial UART connection to the board.
  • On both boards, the tri-colur LED blinks green when the boards are not connected.
  • Open a communication terminal application e.g. Teraterm
  • For each Wahoo board, open a separate terminal window:
    • Find the UART serial (COM) port associated with the board
    • Set the communication parameters to 115200 8N1 with NO hardware flow control
  • The Wahoo boards boot up as BLE peripherals with advertising turned on, in Stream Mode.
    • Note that after a few minutes advertising turns off. See the adv command to turn advertising on if necessary.
    • See Serial Interface for a discussion of stream mode and command mode.
  • We'll refer to the Wahoo boards as Wahoo A and Wahoo B:
  • On Wahoo A, press Button 2 to switch to command mode. The terminal displays COMMAND_MODE.
  • On the Wahoo A terminal:
    • Press the Enter key and wait for a command prompt > and Ready
    • Enter the command scan high. Within a few seconds, TruConnect displays a list of ACKme BLE devices discovered.
      > scan high
      !  # RSSI BD_ADDR           Device Name
      #  1  -89 4C:55:CC:10:07:e1 AMS-07E1
  • Enter the command con <index>, where <index> is the # number corresponding to the device in the devices listed by the scan results.
    > con 1
    Success
  • On both boards, the tri-colour LED lights continuously green when the boards are connected.
  • Now, on WahooA, either press Button 2 (or enter the str stream command into the Wahoo A terminal) to switch WahooA to Stream Mode. The terminal displays STREAM_MODE.
  • With both Wahoo boards in Stream Mode, characters you type on one terminal appear on the other terminal, transmitted from one board to the other wirelessly via the BLE connection.

ModifiedChangesTruConnect Version
Required
2015-03-18Created1.0+