What is it?

The DynaFeather is a Featherwing for connecting to Dynamixel brand smart servo motors. This board includes all the direction control hardware required to communicate with a Dynamixel motor, making them easy to use with Arduino or Circuitpython. The 2.5mm barrel jack, 12V to 5V LDO regulator, and power source shunt allows wireless or battery powered robots to run entirely off the motor power bus when USB isn't plugged in.

Why did you make it?

Dynamixels are a very powerful motor for robotics projects, with great torque for their weight, daisy chain cabling, and all kinds of options like automatic shutoff, speed control, and continuous rotation mode. However, their half-duplex UART communication protocol and special controllers make them a little inaccessible compared to PWM driven hobby servos. My goal was to make a simple, no frills board and accompanying library for Circuitpython that makes them trivial to control with the common Feather board layout.

Features

• Three molex connectors for attaching AX or MX series Dynamixel servos
• UART half-duplex controlled with a SN74HC126 buffer
• Direction control can be moved from D12 to D5 via solder jumpers
• 2x5.5mm power jack for 12V power cable (cable not included)
• Alternative screw terminal for 12V battery power
• 12V to 5V LDO can power the feather independently of USB, selectable with shunt switch

This product is just the DynaFeather and unsoldered pin headers. Dynamixels, Dynamixel cables, host Feather and 2x5.5mm 12V power cable are not included.

Notes:

• Use the shunt switch to avoid supplying the host Feather with both USB and Dynamixel power at once.
• Tested with AX-12 and MX-64 motors, may work with other Dynamixels but check the datasheets first for compatibility.
• Different Dynamixels may require different voltage levels so do not mix them in on the same voltage line without researching first.
• Using many Dynamixels at once might require extra capacitors on the line, see Robotis store for options.
• Circuitpython library for Dynamixels (mine)
• Arduino code for Dynamixels (not mine, untested)