1. Overview

The qik 2s9v1 is Pololu’s second-generation dual serial motor controller. The compact board allows any microcontroller or computer with a serial port (external RS-232 level converter required) or USB-to-serial adapter to drive two small, brushed DC motors with full direction and speed control. The improvements over the previous generation and competing products include:

• high-frequency 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)

Main Features of the Qik 2s9v1

• Simple 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 from 1200 bps to 38.4 kbps;
• Two on-board indicator LEDs (status/heartbeat and serial error indicator) for debugging and feedback.
• Error output to make it easier for the main controller to recover from a serial error condition.
• Jumper-enabled demo mode allowing 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.

Specifications

Important safety warning

This product is not intended for young children! Younger users should use this product only under adult supervision. By using this product, you agree not to hold Pololu liable for any injury or damage related to the use or to the performance of this product. This product is not designed for, and should not be used in, applications where the malfunction of the product could cause injury or damage. Please take note of these additional precautions:

• This product contains lead, so follow appropriate handling procedures, such as not licking the product and washing hands after handling.

• Since the PCB and its components are exposed, take standard precautions to protect this product from ESD (electrostatic discharge), which could damage the on-board electronics. When handing this product to another person, first touch their hand with your hand to equalize any charge imbalance between you so that you don’t discharge through the electronics as the exchange is made.

• Review the instructions carefully before making any electrical connections, and do all wiring while the power is turned off. Incorrect or reversed wiring could cause an electrical short or unpredictable behavior that damages this product and the devices it is connected to.

• This product is designed to be connected to motors, which should be operated safely. Wear safety glasses, gloves, or other protective equipment as appropriate, and avoid dangerous situations such as motors spinning out of control by designing appropriate safeguards and limits into your projects.