TVZ Mechatronics Team / Mbed 2 deprecated L298N-Breakout-Test

Simple test of a L298N breakout board with two DC motors and FRDM-K64F microcontroller board.

Dependencies:   HBridgeDCMotor RateLimiter mbed

This is a cheap L298N breakout board, easily available on ebay or other stores for 2-3 USD.

/media/uploads/tbjazic/l298n_breakout_board.jpg

The schematics of the board is shown on the figure below. There are 3 jumpers placed on the board (CON5, ENA and ENB).

/media/uploads/tbjazic/l298n_breakout_schematics.png

For low voltage DC motors remove a jumper CON5 and connect the supply from battery (5-6 V) to both terminals: +5V and +12V. For supplies larger than 7 V, connect it only to +12V, with the CON5 jumper placed on the board. Study the L298 datasheet for more details.

The following video shows the result of running the program:

Another example is shown in the next video. We now have the supply voltage of 12 V and the jumper CON5 placed. The code is modified a little:

 #include "mbed.h"
 #include "HBridgeDCMotor.h"
 
 HBridgeDCMotor motor(p23, p24);
 
 int main() {
     float sampleTime = 10e-3, switchingFrequency = 25e3, rampTime = 5;
     motor.configure(sampleTime, switchingFrequency, rampTime, rampTime);
     while(true) {
         motor.setDutyCycle(1);
         wait(15);
         motor.setDutyCycle(-1);
         wait(15);
     }
 }

main.cpp@0:92564f74c7d2, 2015-12-11 (annotated)

Committer:
tbjazic
Date:
Fri Dec 11 13:17:35 2015 +0000
Revision:
0:92564f74c7d2
Simple test of a L298N breakout board with two DC motors and a FRDM-K64F microcontroller board.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tbjazic 0:92564f74c7d2 1 #include "mbed.h"
tbjazic 0:92564f74c7d2 2 #include "HBridgeDCMotor.h"
tbjazic 0:92564f74c7d2 3
tbjazic 0:92564f74c7d2 4 HBridgeDCMotor m1(PTC10, PTC11);
tbjazic 0:92564f74c7d2 5 HBridgeDCMotor m2(D6, D7);
tbjazic 0:92564f74c7d2 6
tbjazic 0:92564f74c7d2 7 int main() {
tbjazic 0:92564f74c7d2 8 float sampleTime = 50e-3, switchingFrequency = 25e3, rampTime = 3;
tbjazic 0:92564f74c7d2 9 m1.configure(sampleTime, switchingFrequency, rampTime, rampTime);
tbjazic 0:92564f74c7d2 10 m2.configure(sampleTime, switchingFrequency, rampTime, rampTime);
tbjazic 0:92564f74c7d2 11 while(true) {
tbjazic 0:92564f74c7d2 12 m1.setDutyCycle(1);
tbjazic 0:92564f74c7d2 13 m2.setDutyCycle(1);
tbjazic 0:92564f74c7d2 14 wait(10);
tbjazic 0:92564f74c7d2 15 m1.setDutyCycle(-1);
tbjazic 0:92564f74c7d2 16 m2.setDutyCycle(-1);
tbjazic 0:92564f74c7d2 17 wait(10);
tbjazic 0:92564f74c7d2 18 }
tbjazic 0:92564f74c7d2 19 }