What is it?

This is a small breakout board that allows PWM control of voltage going to four independent DC brushed motors. The board is designed to mount directly on top of a Teensy 3.1 but can be used as a conventional breakout board for breadboarding with Teensy or any Arduino microcontroller. The input power VIN and GND should be connected to a battery or other power source sufficient to drive the motors of your choice. The PWM pins from the microcontroller drive the gate voltage on the four PMV31XN mosfets, allowing the VIN to be delivered to the motors in increments of the PWM output (from 1/256 to 255/256) individually adjustable for each motor independently. This is a pretty standard DC motor control circuit that allows for one-way DC motor operation; a similar circuit controls the DC brushed motors in the open-source CrazyFlie quadcopter (I am using the same mosfets). For the Teensy 3.1 hook up is easy; just mount the board such that VIN and GND match the Teensy 3.1 board pin out, then the PWM pins will be pin 23 for Motor 1, pin 4 for Motor 2, Pin 3 for Motor 3 and Pin 22 for Motor 4. For Arduino, the hook up will be platform-dependent but is straightforward.

The board is open-source hardware; please order it from OSHPark and build your own or order from me to see how it works for you.

Why did you make it?

I wanted a light weight, compact (small) add-on so I could run inexpensive brushed DC motors with the Teensy 3.1 platform. This modular approach is complemented by the Mini and Micro Add-on boards I designed for 9- and 10-DoF motion sensing that use the MPU9250 or LSM9DS0 9-axis motion sensors. With these boards, and the LiPo battery charger and nRF24L01+ 2.4 GHz radio add-ons, one can build a complete system for use in autonomous vehicles such as robots, rovers and, yes, quadcopters!

What makes it special?

This is a simple but robust solution to brushed DC motor control that, while designed specifically to mount on a Teensy 3.1, has utility beyond the Teensy 3.1 platform. All that is necessary is to solder 4 x 2 leads from the motors onto the +/- motor inputs, connect a battery to VIN and GND and the motors can be controlled by software commands through the microprocessor via the PWM output from four GPIO pins. With appropriate PID or other feedback control using output from a motion sensor mounted with the motor controller on the microprocessor, one would have all the elements for controlling the motion of a vehicle in response to changes in orientation or position. This is an inexpensive board that allows the use of inexpensive motors to perform sophisticated motion control tasks limited only by your imagination!

Make sure to connect battery and microprocessor GND and don't connect battery positive to the 3.3 V microprocessor pin! The battery can be connected to the VIN and GND of the Teensy 3.1 and the Arduino (3.3 - 5 V Pro Mini, say) as long as the voltage is less than 5.5 V. Check your microprocessor specs and think it through! For Teensy 3.1 there really is only one way to mount this board. For other microprocessors, it should be straightforward but be careful not to brick your Arduino!