Pololu Jrk G2 21v3 USB Motor Controller with Feedback

Build a “smart DC motor” with real feedback control—without writing a full motor-control stack. The Jrk G2 21v3 is a compact controller for one brushed DC motor that can run closed-loop speed OR position control (choose one mode), configured quickly over USB using Pololu’s free software. It supports multiple control methods (USB, TTL serial, I²C, analog, RC), plus analog or tachometer feedback—ideal for actuators, throttle control, robotics, and DIY servo-style mechanisms.

Power range: operates from 4.5V to 28V (recommended nominal battery up to 24V).
Current capability: up to 2.6A continuous and 5A peak without a heatsink (depends on conditions).
Flexible control interfaces: USB, TTL serial (5V), I²C, analog voltage (pot/joystick), and RC servo pulses.
Feedback options: 0–5V analog feedback (position-style) or frequency/tachometer feedback (speed-style), or no feedback for open-loop.
Quiet PWM: ultrasonic 20kHz PWM (configurable to 5kHz).
Real-world features: configurable accel/decel limits, error responses, optional CRC for robust comms, field-upgradeable firmware.

Important:

Speed OR position (not both): the Jrk can do closed-loop speed control or closed-loop position control, but not simultaneously.
Transient over-voltage: supports transient operation (<500ms) up to 40V, but normal operation is 4.5–28V.
Soldering required: this version includes headers and terminal blocks but they are not soldered. (If you need no-solder, there’s a “connectors soldered” version.)
USB cable not included: needs a USB A to Micro-B cable for configuration.

Why/Benefits

Closed-loop control made easy

Dial-in PID tuning in minutes using Pololu’s configuration utility (Windows/Linux/macOS).
Monitor and test over USB while your mechanism is running.
Set current limits, duty limits, accel/decel ramps, and fault actions.

Plays nicely with your system

Use it like an RC component, a knob-controlled driver, or a microcontroller peripheral.
Quieter motor drive with 20kHz PWM option.
Reversed-power protection + robust serial options (CRC).

Technical specifications

Product	Pololu Jrk G2 21v3 USB Motor Controller with Feedback
Motor type	1× brushed DC motor
Operating voltage	4.5V to 28V (max recommended nominal battery: 24V)
Output current	2.6A continuous, 5A peak (no heatsink)
Transient over-voltage	<500ms up to 40V
Control interfaces	USB, TTL serial (5V), I²C, analog voltage, RC servo pulses
Feedback options	Analog 0–5V, frequency/tachometer, or none
PWM frequency	20kHz (configurable to 5kHz)
Board size	1.0″ × 1.2″
Connectors	Included (not soldered): 0.1″ male header strip + 2× 2-pin 3.5mm terminal blocks

Pinout & power notes

Motor & power connections: the board provides large through-holes for motor and motor-power wiring, and you can use the included 3.5mm terminal blocks if you prefer screw terminals.
Logic/control side: 0.1″ holes support headers for breadboards/perfboards, or you can solder wires directly for the most compact install.
USB configuration: initial setup is done over USB using Pololu’s configuration utility (Micro-B cable required).
Tip: If you need “no soldering,” look for the connectors-soldered Jrk G2 21v3 version.

FAQ

Can it do speed and position control at the same time?

No. The Jrk supports closed-loop speed OR position (choose one), or open-loop control.
How do I control it from Arduino/ESP32?

Use TTL serial or I²C. Pololu also provides an Arduino library to help you get started.
Do I need to solder anything?

For this item (#3142), yes—the included headers and terminal blocks are not soldered. If you want a ready-to-wire version, choose the “connectors soldered” variant.