Pololu Qik 2s9v1 Dual Serial Motor Controller

Pololu's Qik 2s9v1 is an inexpensive and small motor controller that makes it easy to vary the speed and direction of small brushed DC motors from your microcontroller. The controller supplies 1A continous current at 4.5-13.5V with a peak of 3A. The controller itself operates at 3.3V or 5V and uses a serial interface.

Not currently available

Our Code: MCU-60004

Supplier Link: [Pololu MPN:1110]


The qik 2s9v1 is Pololu’s second-generation dual serial motor controller. The compact module allows any microcontroller such as an Arduino or a 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 simpler carrier of the qik’s motor driver, please consider the TB6612FNG dual motor driver carrier, and for a robot controller based on the qik’s 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.

What's Included

The qik ships with a 16×1 straight 0.100" male header strip, a 12×1 right angle 0.100" male header strip, and two red shorting blocks. This hardware offers several options when it comes to making connections to the qik.

For the most compact installation, wires can be directly soldered to the qik pins themselves. For less permanent connections, the 16×1 straight header strip can be broken into a 12×1 piece and two 2×1 pieces. The 2×1 pieces can optionally be soldered into the jumper pins, and the 12×1 header strip of your choice can be soldered into the qik control pins. This allows connections to the qik via custom-made cables that have female headers on them, or the qik can simply be plugged into a breadboard. Using the right angle header allows for a compact profile or for vertical mounting into a breadboard; using the straight header allows for breadboarding as shown in the picture below.


  • Simple bidirectional control of two DC brush motors; please see the user’s guide for more information.
  • 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.



Size: 0.70" x 1.20"
Weight: 2 g1

General specifications

Motor driver: TB6612FNG
Motor channels: 2
Control interface: non-inverted TTL serial2
Minimum operating voltage: 4.5 V
Maximum operating voltage: 13.5 V
Continuous output current per channel: 1 A
Peak output current per channel: 3 A
Maximum PWM frequency: 32 kHz3
Minimum logic voltage: 2.7 V
Maximum logic voltage: 5.5 V
Reverse voltage protection?: Y4


  1. Without included hardware.
  2. Autodetects baud rates between 1200 and 38,400 bps, or can be set for a fixed 38,400 bps baud rate.
  3. Can also be configured to use 15.7 kHz, 7.8 kHz, or 3.9 kHz PWM frequencies.
  4. On motor voltage only; logic voltage does not have reverse protection.


Documentation and other information

Qik 2s9v1 User’s Guide (Printable PDF: qik_2s9v1.pdf)  User's guide for the Pololu Qik 2s9v1 Dual Serial Motor Controller.
Pololu Serial Transmitter utility for Windows (Printable PDF: pololu_serial_transmitter.pdf)  A simple serial transmitter utility for Windows that lets you transmit sequences of bytes at 9600 baud to a selectable COM port. This program can be conveniently used to send commands to our serially controllable devices.

Recommended links

Qik 2s9v1 Arduino Library
Arduino Library for controlling the Pololu qik 2s9v1 dual serial motor controller.