L298 based Motor Driver Probots. Starter Guide

Transcription

1 L298 based Motor Driver Probots Starter Guide Contents 1) Overview 2) Features 3) Using the board to drive motors 4) Internal and external logic supply for the board 5) Troubleshooting and getting help

2 1. Overview 2. Features Maximum motor supply voltage: 46V Maximum motor supply current: 2A per motor Current Sense for each motor Heatsink for better performance Power-On LED indicator 3. Using the board to drive motor Motor driving is extremely simple with the board. The board has two channels A and B. It has 2 inputs and 2 corresponding outputs for each channel. Each channel also has an enable pin and a sense pin. The input pins are the labeled as INP A and INP B. The enable pin is labeled as EN A and EN B, and the sense pin is labeled as SNS A and SNS B.

3 To drive a DC motor in a particular channel, the enable pin of the channel has to be supplied with a logic high (+5V) signal. Then, a logic high signal has to be supplied to the input pins to control the direction of the motor. Supplying logic high to any one of the input pins will drive the DC Motor in one direction. On supply logic high to the other input pin, the motor will run in the opposite direction. Supplying logic high to both input pins will brake the rotation of the motor and supplying a logic low (0V or Gnd) signal to both the input pins will allow the DC motor to rotate freely. The sense pin can be used to sense and limit the amount of current the motor in corresponding channel is consuming. By default this option is not enabled on the board and the sense pin is directly connected to GND through a jumper. It you wish to sense and limit the current being supplied to a motor, you can desolder the jumper and solder a suitable resistor. For choosing the right resistor, please refer the L298 datasheet.

4 4. Internal and external logic supply for the board The L298 requires an input voltage of 5V for its operation. The board has an onboard 5V regulator (LM7805) for the same. It takes the motor input voltage and regulates it to 5V. The regulated voltage can also be supplied to external circuits and can be tapped through the 5V and Gnd header The onboard voltage regulator can work on a maximum input voltage of 35V. If you wish to drive motors with voltages greater than 35V, you will have to supply external 5V for the board, and cut of the input supply to the onboard regulator. This will prevent it from getting damaged due to a high input voltage. You can do this by desoldering the jumper on the bottom side of the board between Pin 1 of the voltage regulator and the +ve Input Voltage pin.

5 Desolder this jumper for driving motors with voltages greater than 35V 5. Troubleshooting and Getting Help Most people face problem driving motors because they use improper power sources. First of all, please make sure that the the power source you are using can drive the motors you wish to control. Secondly, do not forget to provide a logic high to the enable pins of a channel. It is always a good idea to connect the input pins to ground instead of leaving them floating when you are not providing them with a logic high signal. We are committed to ensure that our customers' projects, designs and research go as efficiently and as smoothly as possible. And for this we promise and provide an excellent after-sales support facility. Due to the nature of the products we sell, we are sure to receive a lot of request for support. In anticipation of this, we have created a separate section, "Resources", where we have many tutorials covering

6 how to use our products. Your first step to seek support from us would be to surf through the "Resources" section for answers to your query. If our "Resources" section doesn't address your query, mail us directly at for further support. When you contact us for support, please keep the following things in mind - you will have to provide us with the invoice information(order no., date of purchase, etc.) provide us with all the required details(operating system being used, compiler being used, etc) do not ask us questions or doubts about products we do not sell do not contact us 2 days before a project deadline for any sort of immediate or urgent support do not mail us a rephrased version of your project contact us only if you know what you are doing, do not expect any sort of help from our side otherwise