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hbrobotics / ros_arduino_bridge

ROS + Arduino = Robot
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What type of L298 board are you using? #48

Open dakoner opened 6 years ago

dakoner commented 6 years ago

I spent part of the weekend wondering why the ros_arduino_firmware wasn't doing speed control on my motors. I noticed that the code for the L298 looks like this: https://github.com/hbrobotics/ros_arduino_bridge/blob/indigo-devel/ros_arduino_firmware/src/libraries/ROSArduinoBridge/motor_driver.ino#L76

Specifically, you're PWMing the motor direction pins: if (i == LEFT) { if (reverse == 0) { analogWrite(RIGHT_MOTOR_FORWARD, spd); analogWrite(RIGHT_MOTOR_BACKWARD, 0); } else if (reverse == 1) { analogWrite(RIGHT_MOTOR_BACKWARD, spd); analogWrite(RIGHT_MOTOR_FORWARD, 0); } } else /if (i == RIGHT) //no need for condition/ { if (reverse == 0) { analogWrite(LEFT_MOTOR_FORWARD, spd); analogWrite(LEFT_MOTOR_BACKWARD, 0); } else if (reverse == 1) { analogWrite(LEFT_MOTOR_BACKWARD, spd); analogWrite(LEFT_MOTOR_FORWARD, 0); } }

However, all the L298's that I have, for example this: https://www.amazon.com/DROK-Controller-H-Bridge-Mega2560-Duemilanove/dp/B00CAG6GX2 the speed control is the enable pin, not the FORWARD/BACKWARD pins.

So I am curious what board you have. Otherwise, I think this code must be in error- you're supposed to PWM the enable pins, not the motor direction pins.

YikeStone commented 6 years ago

The code is correct. to use this code you need 4 pwm pins not 2. some corrections are needed in like- LEFT condition is checked and RIGHT motor is manipulated and vice versa. And it will work on any L298Ns.

MSohan14 commented 4 months ago

Ik that it has been a long time but can you tell if you got it to work and if so how?