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Topic: [solved] Did I just fry my L298N motor driver? (Read 5680 times) previous topic - next topic

felixp

Jul 29, 2016, 07:11 pm Last Edit: Jul 30, 2016, 11:27 am by felixp
Hey all,

I just got a L298N and connected it in a similar way as in this image (using only Output 1 for a simple DC motor):



At the very first test I just connected a 8.5V source to the +12V/GND inputs without having the motor or Arduino connected - and within seconds the board became smoking hot!

In a second test, I connected a motor and the Arduino, generated a 2.5V PWM-Signal and set Input 1 high, Input 2 low (moving the motor forward) and again connected the power source, without the motor moving and the board getting hot within seconds.

Also, in another test I removed the jumper for the internal voltage supply and hooked the +5V logic input to the 5V Arduino source - and then a red LED turned on, which didn't happen before (still the same behaviour as before, though).

Does anyone have an idea of what could be going on? Did I get a faulty driver board? Maybe something about running the board in "brake mode" (all inputs low) without a load connected?

Thanks a lot,

Felix

Isaac96

Could we see some pictures of the actual board, not just blurry fritzing pictures?
You may have connected the 8.5V source backwards.
Powering it up in brake mode wouldn't cause any problems.
Where did you get the board?
Do not PM me for help. I will delete immediately.
CONNECT THE GROUNDS!

After Tuesday, even the calendar goes W T F

Southpark

#2
Jul 30, 2016, 12:41 am Last Edit: Jul 30, 2016, 04:19 am by Southpark
Also, in another test I removed the jumper for the internal voltage supply and hooked the +5V logic input to the 5V Arduino source - and then a red LED turned on, which didn't happen before (still the same behaviour as before, though).
Removing the jumper is the right thing to do for supplying the L298N board with an external power supply (where the supply has an supply voltage GREATER than about 12V DC). Here, the '5V' pin on the L298N then changes functionality/behaviour...... with jumper removed, it becomes a voltage supply INPUT pin (instead of a 5V output pin). That '5V' pin on the L298N isn't a 'logic' input pin. It is a pin that provides power to the L298N's own logic circuitry.

Depending on jumper being left in, or left out, that L298N '5V' pin is either a supply input pin, or a supply output pin. When the jumper is connected, the L298N onboard 5V regulator will start working, which provides 5V to the L298N logic circuitry. But when the jumper is disconnected, the L298N logic circuit needs to get its power from somewhere.....so need to connect a 5V supply to that L298N '5V' pin.

felixp

Could we see some pictures of the actual board, not just blurry fritzing pictures?
You may have connected the 8.5V source backwards.
Powering it up in brake mode wouldn't cause any problems.
Where did you get the board?
That was.. embarassingly helpful. While I checked the battery's polarity, I didn't double-check the voltage across the wires connected to V_ss, instead trusted visual inspection. Classic case of over-confidence.  Lesson learned and problem solved!

Isaac96

:)
Look for the obvious 
The first problem I had with the Arduino was choosing the right COM port  :-*
Do not PM me for help. I will delete immediately.
CONNECT THE GROUNDS!

After Tuesday, even the calendar goes W T F

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