Motor driver not working with signal from Arduino

Other Hardware General Electronics
1

Hi Guys,

After almost a year of not touching any electronics I decided to continue the work on my ROV project. I made a L298N motor driver identical to this one made by Solarbotics: Solarbotics L298 Compact Motor Driver Kit - Solarbotics Ltd.

The driver has some LEDs that show the state of the output pins and it seems to work just fine with +5V on the input pins, or even when I touch the input pins. However, it does not work when I connect it to Arduino.

The circuits share a common ground.
The Arduino board is powered via USB.
The rest of the circuit is powered by a different power supply.

I've recorded a short video to show you the problem: - YouTube

Funny thing: When I plug the motor driver into Arduino (running pin13 blink) there's nothing happening. Arduino Pin 13 goes to motor driver input 1. Output 1 does not blink.
I have checked, Arduino outputs +4.8V to driver input 1.

BUT

If I touch input1 and input2 at the same time on the input board, output 1 and output 2 blink on the motor driver board along with ledpin 13 on Arduino.

This is probably some simple electronics mistake that I'm unaware of. Any ideas? Thanks!

2

If you post your code and schematic.....

3

Schematic:
http://postimg.org/image/62kgbtx5j/full/

It's the same as the solarbotics one: https://solarbotics.com/download.php?file=44

Code is just blink pin 13.

4

No, I meant the schematic of the 298 driver board as it's connected to the Arduino, and showing the power. Not the internals of the 298 board.

5

Hi, even though it shows on the diagram, have you got all the grounds connected together, the arduino and the pcb and the power supply for the motor.
I notice that you are using one of the long protoboards, check that the two tracks that run the outside length of the board are continuous.
Some boards have a break in the track half way along.

Tom..... :slight_smile:

6

Hi Tom,

Yes all grounds are connected. I have checked and double checked. Indeed the long lines on the protoboard only go halfway through the board, but I'm only using the right side of the board.

I think there may be an issue with my L298 chip.

@JimboZA - there's nothing fancy about that. Just common ground, different power supplies (USB for Arduino and external supply for the board and motor driver) and pin13 Arduino going to input 1 on the driver board.

I just found out there's an issue with the board. It was working alright last night, before connecting it to Arduino, but now I tested it again and it doesn't seem to behave properly.

Thank you, I'll post back once I find out what happened.

7

So, my topic was dumb.

I used an LM317 regulator for providing 5V to L298N. That worked fine when I first tested the circuit, then at some point it stopped working when I connected to Arduino, which made me think Arduino had something to do with it. I redid the wiring and everything works now.

Thank you for your support!
best, C