UART ttyMFD1 serial port on Intel Edison

On the Intel Edison Arduino board, the J18 Arduino connector block TX/RX pins have the UART connected to /dev/ttyMFD1 in the default Yocto install.

Edison adapter boardGPIO voltage
Arduino5 V
Mini-Breakout1.8 V

The Mini-Breakout board Intel Edison has 1.8 V GPIO and can be damaged from connecting directly to 3.3 V or 5 V TTL logic. You need a level shifter board to do the interface to non-1.8V logic from the Mini-Breakout board.

RX stream from Intel Edison UART

This is intended for a serial device that constantly streams output like a GPS NMEA stream. If your device is interactive, skip to the next section.

  1. At the Edison shell prompt:
   stty -F /dev/ttyMFD1 9600
   cat /dev/ttyMFD1
   

where 9600 is serial port device baudrate 2. text streams to console from UART serial device on Edison.

TX/RX from Intel Edison UART

  1. install

    opkg install screen
    
  2. connect interactively to UART device from the Edison shell

    screen /dev/ttyMFD1 9600
    

where 9600 is serial port device baudrate

Python use of Intel Edison UART

MRAA + PySerial make using the Intel Edison serial port easy from Python.

  1. install MRAA on the Edison
  2. install Pyserial

    python -m pip install pyserial
    
  3. verify serial port operation with:

   import serial
   import mraa

   uart = mraa.Uart(0)

   ser = serial.Serial(uart.getDevicePath(), 9600)

   ser.write("TEST")
   print ser.read(4)
   

References:

Intel Edison GPIO: Getting Started Guide