Jrk G2 18v19 USB Motor Controller with Feedback


Description

Overview

With integrated support for analogue 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 analogue voltages for use with a potentiometer or analogue joystick. They also offer many settings that can be configured using our free configuration software utility. 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).

Jrk G2 18v19 USB Motor Controller with Feedback, bottom view with dimensions.

Jrk G2 18v19 USB Motor Controller with Feedback, bottom view with dimensions.

Jrk G2 18v27 USB Motor Controller with Feedback, bottom view with dimensions.

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
18v19

Jrk G2
24v13

Jrk G2
18v27

Jrk G2
24v21
Recommended max
operating voltage:
28 V(1) 16 V(1) 24 V(2) 34 V(3) 24 V(2) 34 V(3)
Max nominal
battery voltage:
21 V 12 V 18 V 28 V 18 V 28 V
Max continuous current
(no additional cooling):
3 A 12 A 19 A 13 A 27 A 21 A
TTL serial, USB,
Analogue, RC control:
Yes Yes Yes Yes Yes Yes
I²C control: Yes Yes Yes Yes
Hardware current limiting: Yes Yes Yes Yes
Dimensions: 1.35″ × 1.35″ 1.85″ × 1.35″ 1.4″ × 1.2″ 1.7″ × 1.2″
Price: $49.95 $99.95 $99.95 $99.95 $149.95 $149.95

1 Transient protection to 40 V.
2 30 V absolute max.
3 40 V absolute max.

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
    • Analogue voltage for use with a potentiometer or analogue joystick
  • Feedback options:
    • Analogue voltage (0 V to 5 V), for making a closed-loop servo system
    • Frequency pulse counting (for higher-frequency feedback) or pulse timing (for lower-frequency feedback), for closed-loop speed control
    • 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
  • 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 analogue 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

Details for item #3146

Basic pinout diagram of the Jrk G2 18v19 USB Motor Controller with Feedback.

Basic pinout diagram of the Jrk G2 18v19 USB Motor Controller with Feedback.

The Jrk G2 18v19 operates from 6.5 V to 30 V and can deliver a continuous output current of 19 A without a heat sink. Note that 30 V is the absolute maximum for this controller; the maximum recommended operating voltage is 24 V, and the maximum recommended nominal battery voltage is 18 V. For applications using higher voltages (such as 24 V batteries), we recommend the higher-voltage Jrk G2 24v13 or Jrk G2 24v21.

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 24v13 by the number 150 on top of the tall silver electrolytic capacitors.

Included hardware

Jrk G2 18v19 USB Motor Controller with Feedback with included hardware.

Jrk G2 18v19 USB Motor Controller with Feedback with included hardware.

Jrk G2 18v19 or 24v13 USB Motor Controller with included terminal blocks and headers soldered. (1)

Jrk G2 18v19 or 24v13 USB Motor Controller with included terminal blocks and headers soldered. (1)

The Jrk ships with a 0.1″ breakaway male header strip and two 2-pin 5mm terminal blocks. You can solder the terminal blocks to the four large through-holes to make your motor and motor power connections, 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.

A 10-pin piece of 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, or you can solder wires directly to these holes for the most compact installation.

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:

  • Hardware current limiting – the motor driver on the Jrk G2 uses current chopping to actively limit the motor current when it exceeds a software-configurable threshold
  • 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.


Specifications

Dimensions

Size: 1.2″ × 1.4″ × 0.42″1
Weight: 6.5 g1

General specifications

Motor channels: 1
Control interface: USB; non-inverted TTL serial; I²C;
RC servo pulses; analogue voltage
Minimum operating voltage: 6.5 V
Maximum operating voltage: 30 V2
Continuous output current per channel: 19 A3
Maximum PWM frequency: 20 kHz
Reverse voltage protection?: Y
Version: G2 18v19 (30 V max, 19 A max continuous)

Identifying markings

PCB dev codes: umc05a
Other PCB markings: 0J11042, blank white box

Notes:

1
Without included hardware.
2
Absolute maximum; higher voltages can permanently destroy the motor driver. Recommended maximum is approximately 24 V, which leaves a safety margin for ripple voltage on the supply line. Not recommended for use with 24V batteries.
3
Typical results at room temperature with both channels running at 90% duty cycle.

Resources


FAQs

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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