Bi-directional Serial Comminucation with an Arduino Uno

What I have:

  • I have a 4-bit logic level converter.

  • I have a BeagleBone Black running ubuntu, not angstrom. (BBB)

  • I am using the PyBBIO library for serial communication on the BBB.

  • I have the Device Tree Overlay- I have an Arduino Uno.
    What I can/cannot do:

  • I am able to send from the Arduino to the BBB.

  • When I attempt to send from the BBB to the Arduino I cannot.

  • I am able to send from an Tx pin on the BBB to an Rx pin on the BBB.

  • This is over a wire connecting the two together.

  • I have also checked the output of the Tx pin with an Oscilloscope and it is correct.

  • This is true on both sides of the logic level converter.- I cannot send from the Arduino Rx pin from the Arduino Tx pin.

  • This again is over a wire.

  • I do not have the USB plugged in.
    What I think:

  • I think I’m having some sort of problem on my Arduino.

  • I have the ‘L’ LED blinking in my test program and eventually this stops.

  • I believe the program is eventually crashing but I am unsure why.
    I was wondering if someone had any insight to what my problem could be? I am not sure what is happening and I can post any code segments if they would be beneficial.