If you’re planning to build a robot with an Arduino, you’ll probably need a motor shield to drive your motors. The Official Arduino Motor Shield, now available in the Maker Shed, fits right on top of your Arduino Uno (or compatible) microcontroller and uses a full-bridge L298 driver. The L298 driver is capable of providing 2 channels with 5-12V at 2 amps per channel (or 4 amps max with external power supply) to control inductive loads such as relays, solenoids, and DC or stepper motors. It’s perfect for robotics because it is able to control the speed and direction of two DC motors independently, as well as measure the current each motor is using. This means that you can use your motors as an input device by measuring changes in current flow. Did your robot just hit a wall? With the right programming, your Arduino will sense the sudden rise of current from the stalled motors and command your robot to reverse to safety. The shield also features braking so you can stop your robot quickly should the need arise.
Features
- Operating Voltage 5V to 12V
- Motor controller L298P, Drives 2 DC motors or 1 stepper motor
- Max current 2A per channel or 4A max (with external power supply)
- Current sensing 1.65V/A
- Free running stop and brake function
6 thoughts on “New in the Maker Shed: Arduino Motor Shield”
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What this board needs is a revision. You would think they would have put actual jumpers on the board for the Vin, A Brake, B Brake, SNS0 and SNS1 rather then having you cut and resolder those junctions as needed. There is plenty of room on the board for those headers. It would only take a complex reworking of the PCB layout to accommodate them. ;)
At the very least give us a jumper header for the Vin.
Seems easier for most people to simply use the built-in i/o points to control the motors, it is designed to sit right on top of the Arduino after all. Here’s a list of the pins from the site:
This shield have two separate channels, called A and B, that each use
4 of the Arduino pins to drive or sense the motor. In total there are 8
pins in use on this shield.
You can use each channel separately to drive two DC motors or combine
them to drive one unipolar stepper motor.
The shield’s pins, divided by channel are shown in the table below:
Functionpins per Ch. Apins per Ch. B
DirectionD12D13
PWMD3D11
BrakeD9D8
Current SensingA0A1
We have played with the L298Ns for a while and destroyed a couple of them as well, an interesting read on the “2A per channel” spec that clashes with ” maximum power dissipation”
http://ruggedcircuits.com/html/anmd01.html