Pololu High-Power Simple Motor Controller G2 24v19

	Original versions, not recommended for new designs (included for comparison purposes)					G2 versions, released November 2018
	SMC 18v7	SMC 18v15	SMC 24v12	SMC 18v25	SMC 24v23	SMC G2 18v15	SMC G2 24v12	SMC G2 18v25	SMC G2 24v19
Minimum operating voltage:	5.5 V	5.5 V	5.5 V	5.5 V	5.5 V	6.5 V	6.5 V	6.5 V	6.5 V
Recommended max operating voltage:	24 V(1)	24 V(1)	34 V(2)	24 V(1)	34 V(2)	24 V(1)	34 V(2)	24 V(1)	34 V(2)
Max nominal battery voltage:	18 V	18 V	28 V	18 V	28 V	18 V	28 V	18 V	28 V
Max continuous current (no additional cooling):	7 A	15 A	12 A	25 A	23 A	15 A	12 A	25 A	19 A
USB, TTL serial, Analog, RC control:
I²C control:
Hardware current limiting:
Reverse voltage protection:
Dimensions:	2.1" × 1.1"			2.3" × 1.2"		2.1" × 1.1"		1.7" × 1.2"
Available with connectors installed?	Yes	Yes	Yes	No	No	Yes	Yes	No	No
1 30 V absolute max. 2 40 V absolute max.

Details for item #1367

The SMC G2 24v12 operates from 6.5 V to 40 V and can deliver a continuous output current of 19 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 SMC software will tell you. For quick visual identification without a computer, you can distinguish this version from the identically sized SMC G2 18v25 by the number 100 on top of the tall silver electrolytic capacitors.

This version has header pins and terminal blocks included but not soldered, so soldering is required to use it.

Included hardware

The SMC 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 (see Pololu's 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.

Key features of the SMC G2 family

• Simple bidirectional control of one brushed DC motor
• Five communication or control options:
  1. USB interface for direct connection to a PC
  2. Logic-level (TTL) serial interface for use with a microcontroller
  3. I²C interface for use with a microcontroller
  4. Hobby radio control (RC) pulse width interface for direct connection to an RC receiver or RC servo controller
  5. 0 V to 3.3 V analog voltage interface for direct connection to potentiometers and analog joysticks
• Simple configuration and calibration over USB with a free configuration program for Windows
• Reverse-voltage protection
• Hardware current limiting with a configurable threshold
• Current sensing

Note: A USB A to Micro-B cable (not included) is required to connect this controller to a computer.

Additional features of the SMC G2 family

• Adjustable maximum acceleration and deceleration to limit electrical and mechanical stress on the system
• Adjustable starting speed and maximum speed
• Option to brake or coast when speed is zero
• Optional safety controls to avoid unexpectedly powering the motor
• Input calibration (learning) and adjustable scaling degree for analog and RC signals
• Under-voltage shutoff with hysteresis for use with batteries vulnerable to over-discharging (e.g. LiPo cells)
• Adjustable over-temperature threshold and response
• Adjustable PWM frequency from 1.13 kHz to 22.5 kHz (maximum frequency is ultrasonic, eliminating switching-induced audible motor shaft vibration)
• Error LED linked to a digital ERR output, and connecting the error outputs of multiple controllers together optionally causes all connected controllers to shut down when any one of them experiences an error
• Field-upgradeable firmware

• Features of the serial, I²C, and USB interfaces:
  • Optional CRC error detection to eliminate communication errors caused by noise or software faults
  • Optional command timeout (shut off motors if communication ceases)

• Serial features:
  • Controllable from a computer via serial commands sent to the device’s USB virtual serial (COM) port, or via TTL serial through the device’s RX/TX pins
  • TTL serial uses 0 V and 3.3 V on TX, accepts 0 V to 5 V on RX
  • Supports automatic baud rate detection from 1200 bps to 500 kbps, or can be configured to run at a fixed baud rate
  • Supports standard compact and Pololu protocols as well as the Scott Edwards Mini SSC protocol and an ASCII protocol for simple serial control from a terminal program
  • Optional serial response delay for communicating with half-duplex controllers such as the Basic Stamp
  • Controllers can be easily chained together and to other Pololu serial motor and servo controllers to control hundreds of motors using a single serial line

• I²C features:
  • Compatible with I²C bus voltage levels from 1.8 V to 5 V

• USB features:
  • Full-speed USB interface (12 Mbps)
  • Example code in C#, Visual Basic .NET, and Visual C++ is available in the Pololu USB Software Development Kit

• RC features:
  • 1/4 µs pulse measurement resolution
  • Works with RC pulse frequencies from 10 to 333 Hz
  • Configurable parameters for determining what constitutes an acceptable RC signal
  • Two RC channels allow for single-stick (mixed) motor control, making it easy to use two simple motor controllers in tandem on an RC-controlled differential-drive robot
  • RC channels can be used in any mode as limit or kill switches (e.g. use an RC receiver to trigger a kill switch on your autonomous robot)
  • Battery elimination circuit (BEC) jumper can power the RC receiver with 5 V or 3.3 V

• Analog features:
  • 0.8 mV (12-bit) measurement resolution
  • Works with 0 to 3.3 V inputs
  • Optional potentiometer/joystick disconnect detection
  • Two analog channels allow for single-stick (mixed) motor control, making it easy to use two simple motor controllers in tandem on a joystick-controlled differential-drive robot
  • Analog channels can be used in any mode as limit or kill switches

This video demonstrates the versatility of the Simple Motor Controller by showing how it can be controlled directly from the analog output of a Sharp analog distance sensor—there is no intermediate control board and no programming involved. The unit in the video is one of Pololu's original SMCs, but the newer SMC G2s have the same capabilities. For more information on this example, including the SMC settings file and a list of parts used, see Pololu's blog post about the demo.

Comparison to the original Simple Motor Controllers

The SMC G2 family features a number of improvements compared to Pololu's original Simple Motor Controllers with green PCBs:

• Reverse voltage protection
• Configurable hardware current limiting – the motor drivers on the SMC G2 use current chopping to actively limit the motor current when it exceeds a software-configurable threshold
• I²C interface provides an additional control option
• USB Micro-B connector (instead of Mini-B as on the original SMCs)
• The SMC G2 18v25 and 24v19 use a four-layer board with double-sided assembly, which lets them be much smaller than their original counterparts (the SMC 18v25 and 24v23)

The SMC G2 controllers have the same pin arrangements as the original SMCs, so Pololu should be usable as drop-in replacements in typical applications, though note that the minimum operating voltage is a little higher for the G2 versions (6.5 V vs 5.5 V for the originals). The SMC G2 serial protocol is compatible with (and generally a superset of) the original SMC serial protocol, so in most cases, serial interface software running on a microcontroller or computer will not need to be modified to work with a SMC G2.

People often buy this product together with:

High-Power Simple Motor Controller G2 24v12

Dimensions

General specifications

Identifying markings

Notes:

1

Without included hardware.

2

Autodetects baud rates between 1200 and 500,000 bps, or can be set to any fixed baud rate in this range.

3

Absolute 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.

4

Typical results at room temperature running at 90% duty cycle.

5

All digital inputs are 5V tolerant.

Documentation and other information

• 

  Pololu Simple Motor Controller G2 User’s Guide (Printable PDF)

  User’s manual for the Pololu Simple Motor Controller G2.

• Pololu USB Software Development Kit

  The Pololu USB SDK contains example code for making your own applications that use native USB to control the Jrk Motor Controller, Maestro Servo Controller, Simple Motor Controller, or USB AVR Programmer.

File downloads

• Simple Motor Controller G2 Software and Drivers for Windows (550k zip)

• Dimension diagram of the High-Power Simple Motor Controller G2 18v25 or 24v19 (379k pdf)

• Dimension diagram of the High-Power Simple Motor Controller G2 18v15 or 24v12 (424k pdf)

• 3D model of the High-Power Simple Motor Controller G2 18v25 or 24v19 (12MB step)

• 3D model of the High-Power Simple Motor Controller G2 18v15 or 24v12 (12MB step)

• Drill guide for High-Power Simple Motor Controller G2 18v25 or 24v19 (102k dxf)

  This DXF drawing shows the locations of all of the board’s holes.

• Drill guide for High-Power Simple Motor Controller G2 18v15 or 24v12 (100k dxf)

  This DXF drawing shows the locations of all of the board’s holes.