Pololu Qik 2s9v1 Dual Serial Motor Controller Overview The qik 2s9v1 is Pololus second-generation dual serial motor controller. The compact module allows any microcontroller or computer with a serial port (external RS-232 level converter required) or USB-to-serial adapter to easily drive two small, brushed DC motors with full direction and speed control. It provides ultrasonic, 8-bit PWM speed control via an advanced, two-way serial protocol that features automatic baud rate detection up to 38.4 kbps and optional CRC error checking. Two status LEDs give visual feedback about the serial connection and any encountered error conditions, making debugging easy, and a demo mode allows easy verification of proper operation. The improvements over the previous generation and competing products include: high-frequency (ultrasonic) PWM to eliminate switching-induced motor shaft hum or whine a robust, high-speed communication protocol with user-configurable error condition response visible LEDs and a demo mode to help troubleshoot problematic installations reverse power protection on the motor supply (not on the logic supply) For a more advanced, higher-power version of this controller, please consider the qik 2s12v10. For a simpler carrier of the qiks motor driver, please consider the TB6612FNG dual motor driver carrier, and for a robot controller based on the qiks driver, please consider the Baby Orangutan and Orangutan SV-328 robot controllers and 3pi robot, which connect the TB6612 to a user- programmable AVR microcontroller. November 27, 2013 update: We are transitioning to a version of this board that replaces the large, silver electrolytic capacitor with a much smaller ceramic capacitor. This lowers the profile of the board but does not affect functionality at all. During the transition, you might receive either version of the board. Main Features of the Qik 2s9v1Simple bidirectional control of two DC brush motors. 4.5 V to 13.5 V motor supply range. 1 A maximum continuous current per motor (3 A peak). 2.7 V to 5.5 V logic supply range. Logic-level, non-inverted, two-way serial control for easy connection to microcontrollers or robot controllers. Optional automatic baud rate detection. Two on-board indicator LEDs (status/heartbeat and serial error indicator) for debugging and feedback. Serial error output to make it easier for the main controller to recover from a serial error condition. Jumper-enabled demo mode allows initial testing without any programming. Optional CRC error detection eliminates serial errors caused by noise or software faults. Optional motor shutdown on serial error or timeout for additional safety. Supports daisy-chaining the qik to other qiks and Pololu serial motor and servo controllers, allowing the control of up to hundreds of motors and servos with a single serial line. Comprehensive users guide. Specifications Motor channels: 2 Motor supply voltage: 4.5 13.5 V Continuous output current per 1 A channel: Peak output current per channel: 3 A Auto-detect baud rate range: 1200 38400 bps Fixed baud rate: 38400 bps