TReX Dual Motor Controller

The TReX Dual-Motor Controller is a versatile, high-power DC motor controller designed to seamlessly blend autonomous and human control of small and medium sized robots. The TReX can control two bidirectional and one unidirectional motor via multiple independent control interfaces: radio control (RC) servo pulses, analog voltage, and asynchronous serial (RS-232 or TTL). It maintains compactness through a two-board design that features the VNH2SP30-based Dual High-Current Motor Driver Carrier as its bottom layer. (For a lower-power version of the TReX, please consider the TReX Jr).

The TReX uses five input channels to receive the RC or analog control signals. When operating in RC or analog mode, the five channels function as follows:
Channel 1: motor 1 speed and direction or, if in mix mode, turn left/right
Channel 2: motor 2 speed and direction or, if in mix mode, go forward/reverse
Channel 3: auxiliary (unidirectional) motor speed
Channel 4: can be used to enable “flipped mode”, which allows invertible robots to be controlled as normal when they are inverted
Channel 5: determines whether the motors are controlled by the channel inputs or the serial interface; this channel allows you to switch between autonomous and human control at will

The serial interface can switch instantly with one of the other two interfaces, allowing mixed autonomous and remote control. For example, a robot could be configured to run autonomously most of the time, but a human operator could override the autonomous function if the robot gets stuck or into a dangerous situation. If the serial mode is selected as the primary interface, high-resolution measurements of all five channel input signals (be they RC pulses or analog voltages) are made available to the autonomous robot controller, allowing for complex and unlimited mixing of operator control and sensor input. 

Motor Driver: VNH2SP30
Continuous Paralleled output current per channel: 25A
Current sense: 0.13 V/A
Maximum PWM frequency: 19.5 kHz
Reverse Voltage Protection: Yes
Speed Control: 128 steps in each direction
RC Pulse Measurement: 12-bit resolution, 1µsec accuracy
Analog Measurements: 10-bit resolution
Serial Interface: both RS-232 and TTL (logic level), bidirectional
Baud Rates: supports 11 common baud rates ranging from 1,200 to 115,200 bps
Expanded Protocol: Allows multiple Pololu servo and motor controllers on one serial line
Compact Protocol: Allow both motors 1 and 2 to be simultaneously set with just three bytes