Jrk G2 21v3 USB Motor Controller with Feedback

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Pololu item #: 3142
Brand: Pololu
Status: Active and Preferred 
RoHS 3 compliant


This compact motor controller makes closed-loop speed or position (but not both!) control of a brushed DC motor easy, with quick configuration over USB using our free software. It supports five control interfaces: USB, TTL serial, I²C, analog voltage (potentiometer), and hobby radio control (RC). This version offers a 4.5 V to 28 V operating range and can deliver continuous output currents up to 2.6 A (5 A peak) without a heat sink. Male headers and terminal blocks are included but not soldered, allowing for custom installations.

Alternatives available with variations in these parameter(s): version Select variant…

Pictures

Jrk G2 21v3 USB Motor Controller with Feedback.

Jrk G2 21v3 USB Motor Controller with Feedback, top view.

Jrk G2 21v3 USB Motor Controller with Feedback, bottom view with dimensions.

Jrk G2 21v3 USB Motor Controller with Feedback with included hardware.

Jrk G2 21v3 USB Motor Controller with Feedback (Connectors Soldered).

Jrk G2 21v3 USB Motor Controller with Feedback (Connectors Soldered), top view.

Basic pinout diagram of the Jrk G2 21v3 USB Motor Controller with Feedback.

Jrk G2 21v3 USB Motor Controller with Feedback, bottom view.

Comparison of the newer Jrk G2 21v3 (black PCB) with the original Jrk 21v3 (green PCB).

Side-by-side comparison of the different Jrk G2 USB Motor Controllers with Feedback.

The graph window in the Jrk G2 Configuration Utility (version 1.2.0).

The main window and the variables window in the Jrk G2 Configuration Utility (version 1.2.0).




Overview


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 our 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 is required to connect the Jrk G2 to a computer).

The table below lists the members of the Jrk family, including the original (green) versions, and shows the key differences among them.


Jrk
21v3

Jrk
12v12

Jrk G2
21v3

Jrk G2
18v19

Jrk G2
24v13

Jrk G2
18v27

Jrk G2
24v21
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 Yes Yes Yes Yes Yes Yes
I²C control: Yes Yes Yes Yes Yes
Hardware current limiting: Yes Yes Yes Yes
Dimensions: 1.35″ × 1.35″ 1.85″ × 1.35″ 1.0″ × 1.2″ 1.4″ × 1.2″ 1.7″ × 1.2″
Price: $49.95 $149.95 $49.95 $99.95 $99.95 $149.95 $149.95
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.

Pololu Jrk G2 18v19 USB Motor Controller with Feedback controlling an industrial-duty linear actuator with an RC receiver.

Pololu Jrk G2 18v27 USB Motor Controller with Feedback controlling a high-power motor from USB.

Main features of the Jrk G2 family

Details for item #3142

The Jrk G2 21v3 operates from 4.5 V to 28 V and can deliver a continuous output current of 2.6 A (5 A peak) without a heat sink. The controller supports transient operation (< 500 ms) up to 40 V, and the maximum recommended nominal battery voltage is 24 V. This version has header pins and terminal blocks included but not soldered, so soldering is required to use it.

A version is also available that requires no soldering to use as the terminal blocks and main header pins are already installed.

Included hardware

The Jrk ships with a 0.1″ breakaway male header strip and two 2-pin 3.5mm terminal blocks. You can solder the terminal blocks to the four large through-holes to make your motor and motor power connections (see our short video on terminal block installation), or you can solder a couple of 2-pin pieces of the 0.1″ header strip into the smaller through-holes above and below these larger holes.

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, perfboards, or 0.1″ connectors. For the most compact installation, you can just solder wires directly to the holes.

Note: A USB A to micro-B cable (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 our 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:

Comparison of the newer Jrk G2 21v3 (black PCB) with the original Jrk 21v3 (green PCB).

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.

Dimensions

Size: 1.2″ × 1.0″ × 0.3″1
Weight: 4.5 g1

General specifications

Motor channels: 1
Control interface: USB; non-inverted TTL serial; I²C;
RC servo pulses; analog voltage
Minimum operating voltage: 4.5 V2
Maximum operating voltage: 28 V3
Continuous output current per channel: 2.6 A4
Maximum PWM frequency: 20 kHz
Reverse voltage protection?: Y
Version: G2 21v3 (28 V max, 2.6 A max continuous)
Connectors soldered?: N

Identifying markings

PCB dev codes: umc06a
Other PCB markings: 0J11316

Notes:

1
Without included hardware.
2
Powering the Jrk G2 21v3 with a supply voltage between 4.5 V and 5.5 V might cause its logic voltage to be lower than normal, which could affect operation. See the user’s guide for more information.
3
Transient operation (< 500 ms) up to 40 V.
4
Typical results at room temperature running at 90% duty cycle with VIN > 8 V. Operation from 4.5 V to 8 V reduces maximum current output.

Documentation and other information

File downloads

Recommended links

Frequently-asked questions

Does the Jrk support using a quadrature encoder for feedback?
The Jrk motor controllers do not work with encoders, in the sense that you cannot get position control over unlimited number of rotations. (The Jrks are typically used with potentiometer feedback, which allows for up to a few rotations when using multi-turn potentiometers.)

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