Intel Edison: using UART ttyMFD1 serial port

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. With the Arduino Edison adapter board, these pins are 5V TTL.

However, if you use the Mini-Breakout board for the Edison, the GPIO is 1.8 V, 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.

Talk to a serial device connected to the Intel Edison UART

SSH into the Edison or connect to the USB debug port and at the Edison shell prompt:

stty -F /dev/ttyMFD1 baud
cat /dev/ttyMFD1

where “baud” is your baud e.g. 4800 or 9600 etc.

and you’ll see the text coming in from whatever you’re connected to say a GPS streaming NMEA.

If you’ve installed screen via

opkg install screen

you can connect interactively to your UART device from the Edison shell by

screen /dev/ttyMFD1 baud

Use the Intel Edison UART Serial port programmatically

I would encourage using MRAA + PySerial from Python:

References:

Intel Edison Arduino and Mini Breakout board GPIO Getting Started Guide