> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # Jrk G2 24v21 USB Motor Controller with Feedback **Type:** Product page · **SKU:** POLOLU-3149 · **Brand:** [Pololu](https://core-electronics.com.au/brands/pololu-australia) **Page:** https://core-electronics.com.au/jrk-g2-24v21-usb-motor-controller-with-feedback.html ([markdown](https://core-electronics.com.au/jrk-g2-24v21-usb-motor-controller-with-feedback.html.md)) This powerful motor controller makes closed-loop speed or position (but not both!) control of a brushed DC motor easy, with quick configuration over USB... ## Pricing - **Price:** $244.95 (inc GST) — $222.68 AUD, exc GST - **Quantity discounts:** 5+ $213.77 (exc GST) · 10+ $207.09 (exc GST) ## Availability & dispatch - Available with a lead time — expect dispatch between Aug 25 and Aug 28. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=POLOLU-3149:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/POLOLU-3149:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## Description With integrated support for analog voltage or tachometer (frequency) feedback, the second-generation G2 family of Jrk motor controllers makes it easy to add closed-loop control of speed or position (but not both!) of a single brushed DC motor to a variety of projects. These versatile, general-purpose modules support five different control interfaces: USB for direct connection to a computer, TTL serial and I²C for use with a microcontroller, RC hobby servo pulses for use in an RC system, and analog voltages for use with a potentiometer or analog joystick. They also offer many settings that can be configured using Pololu's free configuration software utility for Windows, Linux, and macOS. This software simplifies initial setup of the device and allows for in-system testing and monitoring of the controller via USB (a [micro-B USB cable](https://core-electronics.com.au/thin-2mm-usb-cable-a-to-micro-b-6-ft-low-full-speed-only.html) is required to connect the Jrk G2 to a computer). | [![](https://core-electronics.com.au/attachments/localcontent/0J8919_740753ea2a0.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8919_252132efa00.jpg) | |---| The table below lists the members of the Jrk family, including the original (green) versions, and shows the key differences among them. | | ![](https://core-electronics.com.au/attachments/localcontent/0J1595_28844ad034.jpg) [Jrk 21v3](https://core-electronics.com.au/pololu-jrk-21v3-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J1755_349515e64f.jpg) [Jrk 12v12](https://core-electronics.com.au/pololu-jrk-12v12-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J8913_25851beb35.jpg) [Jrk G2 21v3](https://core-electronics.com.au/jrk-g2-21v3-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J8643_3123b53c46.jpg) [Jrk G2 18v19](https://core-electronics.com.au/jrk-g2-18v19-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J8647_29266f980f.jpg) [Jrk G2 24v13](https://core-electronics.com.au/pololu-jrk-g2-24v13-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J8651_3520870713.jpg) [Jrk G2 18v27](https://core-electronics.com.au/jrk-g2-18v27-usb-motor-controller-with-feedback.html) | ![](https://core-electronics.com.au/attachments/localcontent/0J8655_3539c90c5c.jpg) [Jrk G2 24v21](https://core-electronics.com.au/jrk-g2-24v21-usb-motor-controller-with-feedback.html) | |---|---|---|---|---|---|---|---| | Recommended max operating voltage: | 28 V**(1)** | 16 V | 28 V**(1)** | 24 V**(2)** | 34 V**(3)** | 24 V**(2)** | 34 V**(3)** | | Max nominal battery voltage: | 24 V | 12 V | 24 V | 18 V | 28 V | 18 V | 28 V | | Max continuous current (no additional cooling): | 2.5 A**\*** | 12 A | 2.6 A | 19 A | 13 A | 27 A | 21 A | | USB, TTL serial, Analog, RC control: | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | | I²C control: | | | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | | Hardware current limiting: | | | | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | ![Yes](https://core-electronics.com.au/attachments/localcontent/check-fa31fa0963023302eb66fe206c0d1e8cb1135facdac9a4e8f5b5ffcc3c3ea377_29454a38f.png) | | Dimensions: | 1.35" × 1.35" | 1.85" × 1.35" | 1.0" × 1.2" | 1.4" × 1.2" | 1.7" × 1.2" | | | | **1** Transient operation (< 500 ms) up to 40 V. **2** 30 V absolute max. **3** 40 V absolute max. **\*** Reduced from “3 A” based on newer, more stringent tests. The value now is directly comparable to the rating for the newer G2 21v3. | | [![](https://core-electronics.com.au/attachments/localcontent/0J8668_1327936cd94.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8668_235668a4c56.jpg) | |---| | Pololu Jrk G2 18v19 USB Motor Controller with Feedback controlling an industrial-duty linear actuator with an RC receiver. | | [![](https://core-electronics.com.au/attachments/localcontent/0J8669_204215d0281.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8669_4252318e521.jpg) | |---| | Pololu Jrk G2 18v27 USB Motor Controller with Feedback controlling a high-power motor from USB. | **Main features of the Jrk G2 family** - Easy open-loop or closed-loop control of one brushed DC motor - A variety of control interfaces: - **USB** for direct connection to a computer - **TTL serial** operating at 5 V for use with a microcontroller - **I²C** for use with a microcontroller - **RC hobby servo pulses** for use in an RC system - **Analog voltage** for use with a potentiometer or analog joystick - Feedback options: - **Analog voltage** (0 V to 5 V), for making a closed-loop servo system - **Frequency**, for closed-loop speed control using pulse counting (for higher-frequency feedback) or pulse timing (for lower-frequency feedback) - **None**, for open-loop speed control - *Note:* the Jrk does not support using quadrature encoders for position control - Ultrasonic 20 kHz PWM for quieter operation (can be configured to use 5 kHz instead) - Simple configuration and calibration over USB with free configuration software utility (for Windows, Linux, and macOS) - Configurable parameters include: - PID period and PID coefficients (feedback tuning parameters) - Maximum current - Maximum duty cycle - Maximum acceleration and deceleration - Error response - Input calibration (learning) for analog and RC control - Optional CRC error detection eliminates communication errors caused by noise or software faults - Reversed-power protection - Field-upgradeable firmware - Optional feedback potentiometer disconnect detection - [Arduino library](https://github.com/pololu/jrk-g2-arduino) makes it easy to get started using these controllers with an [Arduino](https://core-electronics.com.au/search/?q=arduino+compatible) or compatible board - Comprehensive user’s guide **Details for item #3149** | [![](https://core-electronics.com.au/attachments/localcontent/0J8665_608230ab7d5.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8665_14761d2d130.jpg) | |---| The Jrk G2 24v21 operates from **6.5 V to 40 V** and can deliver a continuous output current of **21 A** without a heat sink. Note that 40 V is the absolute maximum for this controller; the maximum recommended operating voltage is **34 V**, and the maximum recommended nominal battery voltage is **28 V**. If you need to identify which version you have, you can just plug it into a computer through USB and the Jrk software will tell you. For quick visual identification without a computer, you can distinguish this version from the identically sized Jrk G2 18v27 by the number **100** on top of the tall silver electrolytic capacitors. **Included hardware** | \| [![](https://core-electronics.com.au/attachments/localcontent/0J8656_302515f7f27.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8656_44588dbeb56.jpg) \| \|---\| | \| [![](https://core-electronics.com.au/attachments/localcontent/0J8663_166241aebf9.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8663_57104808a37.jpg) \| \|---\|---\| | |---| The Jrk ships with a [0.1" breakaway male header strip](https://core-electronics.com.au/0-100-2-54-mm-breakaway-male-header-1x40-pin-straight.html) and two [2-pin 5mm terminal blocks](https://core-electronics.com.au/screw-terminal-block-2-pin-5-mm-pitch-side-entry-4-pack.html). You can solder the terminal blocks to the four large through-holes to make your motor and motor power connections (see Pololu's short [video on terminal block installation](https://www.youtube.com/watch?v=6pDyTLRZ2Eg)), or you can solder an 8-pin piece of the 0.1" header strip into the smaller through-holes that border these larger holes. Note, however, that the terminal blocks are only rated for 16 A, and each header pin pair is only rated for a combined 6 A, so for higher-power applications, thick wires should be soldered directly to the board. Pieces from the 0.1" header strip can be soldered into the small holes on the logic connection side of the board to enable use with [solderless breadboards](https://core-electronics.com.au/prototyping/breadboards.html), perfboards, or [0.1" connectors](https://core-electronics.com.au/connectors-sockets/crimp-connector-housings.html), or you can solder wires directly to these holes for the most compact installation. **Note:** A [USB A to micro-B cable](https://core-electronics.com.au/thin-2mm-usb-cable-a-to-micro-b-6-ft-low-full-speed-only.html) (not included) is required to connect the Jrk G2 to a computer for initial configuration. **Comparison to the original Jrk motor controllers** The Jrk G2 family features a number of improvements compared to Pololu's original two Jrk motor controllers (21v3 and 12v12). Most importantly, the Jrk G2 controllers support both higher operating voltages and larger output currents while being even more compact than their predecessors. Other new features include: | [![](https://core-electronics.com.au/attachments/localcontent/0J8917_54651753e40.jpg)](https://core-electronics.com.au/attachments/localcontent/0J8917_7050118322b.jpg) | |---| | Comparison of the newer Jrk G2 21v3 (black PCB) with the original Jrk 21v3 (green PCB). | - Configurable hardware current limiting on higher-power versions – the motor drivers on the Jrk G2 18v19, 18v27, 24v13, and 24v21 use current chopping to actively limit the motor current when it exceeds a software-configurable threshold (the Jrk G2 21v3 has fixed hardware current limiting and optional software current limiting) - More accurate speed control at low tachometer frequencies - I²C interface provides an additional control option - VIN measurement capability allows monitoring of battery or power supply - USB Micro-B connector (instead of Mini-B as on the original Jrk controllers) - Configurable deceleration limiting (the original Jrks just supported configurable acceleration limiting) - PID coefficients can now be adjusted on the fly over the serial, I²C, and USB interfaces The Jrk G2 controllers are *not* drop-in replacements for the original Jrk controllers because of differences in their form factors and pin arrangements, although wiring changes should be straightforward. The Jrk G2 serial protocol is compatible with (and generally a superset of) the original Jrk serial protocol, so in many cases, serial interface software running on a microcontroller or computer will not need to be modified to work with a Jrk G2. **People often buy this product together with:** | [![Pololu RC Switch with Relay (Assembled)](https://core-electronics.com.au/attachments/localcontent/0J4777_4756cff77b.jpg)](https://core-electronics.com.au/pololu-rc-switch-with-relay-assembled.html) | [Pololu RC Switch with Relay (Assembled)](https://core-electronics.com.au/pololu-rc-switch-with-relay-assembled.html) | |---|---| | [![Mounting Bracket for Glideforce Industrial-Duty Linear Actuators - Aluminum](https://core-electronics.com.au/attachments/localcontent/0J8327_38473dd738.jpg)](https://core-electronics.com.au/mounting-bracket-for-glideforce-industrial-duty-linear-actuators-aluminum.html) | [Mounting Bracket for Glideforce Industrial-Duty Linear Actuators - Aluminum](https://core-electronics.com.au/mounting-bracket-for-glideforce-industrial-duty-linear-actuators-aluminum.html) | |---|---| | [![Glideforce LACT6-1000BPL Industrial-Duty Linear Actuator with Ball Screw Drive and Feedback: 450kgf, 6" Stroke (4.8" Usable), 0.66"/s, 12V](https://core-electronics.com.au/attachments/localcontent/0J8346_269563bb96.jpg)](https://core-electronics.com.au/glideforce-lact6-1000bpl-industrial-duty-linear-actuator-with-ball-screw-drive-and-feedback-450kgf-6-stroke-4-8-usable-0-66-s-12v.html) | [Glideforce LACT6-1000BPL Industrial-Duty Linear Actuator with Ball Screw Drive and Feedback: 450kgf, 6" Stroke (4.8" Usable), 0.66"/s, 12V](https://core-electronics.com.au/glideforce-lact6-1000bpl-industrial-duty-linear-actuator-with-ball-screw-drive-and-feedback-450kgf-6-stroke-4-8-usable-0-66-s-12v.html) | |---|---| **Dimensions** | Size: | 1.2" × 1.7" × 0.42"[1](https://core-electronics.com.au/#note1) | |---|---| | Weight: | 10 g[1](https://core-electronics.com.au/#note1) | **General specifications** | Motor channels: | 1 | |---|---| | Control interface: | USB; non-inverted TTL serial; I²C; RC servo pulses; analog voltage | | Minimum operating voltage: | 6.5 V | | Maximum operating voltage: | 40 V[2](https://core-electronics.com.au/#note2) | | Continuous output current per channel: | 21 A[3](https://core-electronics.com.au/#note3) | | Maximum PWM frequency: | 20 kHz | | Reverse voltage protection?: | Y | | Version: | G2 24v21 (40 V max, 21 A max continuous) | | Connectors soldered?: | N | **Identifying markings** | PCB dev codes: | umc04a | |---|---| | Other PCB markings: | 0J10858, blank white box | **Notes:** 1Without included hardware.2Absolute maximum; higher voltages can permanently destroy the motor driver. Recommended maximum is approximately 34 V, which leaves a safety margin for ripple voltage on the supply line.3Typical results at room temperature running at 90% duty cycle. **Documentation and other information** - ![](https://core-electronics.com.au/attachments/localcontent/0J8651_5059b0ef2a.jpg)**Jrk G2 Motor Controller User’s Guide (Printable PDF)** User’s manual for the Pololu Jrk G2 USB Motor Controllers with Feedback. **File downloads** - **Jrk G2 Software and Drivers for Windows (11MB msi)** - **Jrk G2 Software for Linux (x86) (9MB xz)** - **Jrk G2 Software for Linux (Raspberry Pi) (6MB xz)** - **Jrk G2 Software for macOS (8MB pkg)** - **Dimension diagram of the Jrk G2 21v3 USB Motor Controller with Feedback (215k pdf)** - **Dimension diagram of the Jrk G2 18v19 and 24v13 motor controllers (220k pdf)** - **Dimension diagram of the Jrk G2 18v27 and 24v21 motor controllers (208k pdf)** - **3D model of the Jrk G2 21v3 USB Motor Controller with Feedback (11MB step)** - **3D model of the Jrk G2 18v19 and 24v13 motor controllers (11MB step)** - **3D model of the Jrk G2 18v27 and 24v21 motor controllers (11MB step)** - **Drill guide for the Jrk G2 21v3 USB Motor Controller with Feedback (59k dxf)** This DXF drawing shows the locations of all of the board’s holes. - **Drill guide for the Jrk G2 18v19 and 24v13 motor controllers (83k dxf)** This DXF drawing shows the locations of all of the board’s holes. - **Drill guide for the Jrk G2 18v27 and 24v21 motor controllers (95k dxf)** This DXF drawing shows the locations of all of the board’s holes. **Recommended links** - **[Jrk G2 library for Arduino](https://github.com/pololu/jrk-g2-arduino)** This is a library for the Arduino IDE that helps interface with a Jrk G2 USB Motor Controller with Feedback using serial or I²C. - **[Jrk G2 software source code](https://github.com/pololu/pololu-jrk-g2-software)** This repository contains the source code of the Pololu Jrk G2 Configuration Utility (jrk2gui) and the Pololu Jrk G2 Command-line Utility (jrk2cmd). It also has drivers for Windows and build instructions. ## Images - [Product image 1](https://core-electronics.com.au/media/catalog/product/i/m/image_6036.jpg)