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Did I break my VNH2SP30 motor driver?

I was trying to connect a VNH2SP30 content.solarbotics.com/products … ry-gm8.pdf. When I connected the battery to the motor driver, the red LED flashed erratically for a little over a second then stopped, the battery felt very warm, and there was a slight burning smell before I could get the battery disconnected.

I don’t know if I used the wrong power or if I wired it wrong. I followed the diagram in this post Dual VNH2SP30 MD03A with Arduino: Programming, PWM issues, and afterwards I double checked that the VIN and GND were correct and all the batteries in the holder were in the right directions.

I used 3 Li-ion AA batteries with 3.2V 400mAh each. I thought the voltage would be 9.6, and it would be ok for the driver and the motors. I haven’t added the 2 capacitors that came with the board because I thought they were just for interference and I could add them later.

Does it sound like the problem was with the wrong kind of battery, bad wiring, or something else? Is there a way I can fix my motor driver?

Thanks for any help. I really appreciate it.
~A

Hello.

Sorry to hear you are having trouble with your VNH2SP30 motor driver carrier. Unfortunately, your problem sounds like a wiring issue that has probably irreversibly damaged the driver. If you have been only using one channel, it might be possible that the other one is still okay. Can you post a picture of your setup as you have it now? Also, if you could post a diagram like the one in the forum you linked to showing exactly how you had everything connected, that could be very helpful in diagnosing the problem.

I noticed a couple of other small things. The diagram in that forum post shows the Arduino being powered from 5V, which is not in the recommended input voltage range. Are you sure your Li-ion cell voltage is not 3.7V?

- Ryan

Hi,

Thanks for your help. I was powering the Arduino over USB, which I believe is 5V. I thought this was ok to power just the logic, since (if all went well) the motor would be powered from the other power source (batteries.) Also, I checked the batteries, and they are labelled 3.2V each. I remember this being different from all the other batteries when I bought them.

Here is the photo of the setup. I think the problem might be that I didn’t ground the motor correctly. I connected the motor ground (brown) to the motor driver ground terminal, but I didn’t know exactly where it should connect to the motor itself. So I taped it to the plastic outside of the motor. (It’s left hanging in the picture/diagram.)


Here is the diagram. I kept the wires the same color as in the photo.



This is my 3rd robot project, and the first time I’ve tried striking out on my own instead of following kit instructions. Thank you!

~A

Thanks for posting the pictures, it makes it a whole lot easier to see what you are doing.

Good news, I see problems with your wiring, which means your board might not be broken!

But first some recommendations:

  1. It is really easy to short wires when you use crimped wires without crimp connector housings
  2. I typically do not recommend grounding the motor casing
  3. It is fine to power the Arduino with USB. The diagram you linked to showed 5Vs being connected to the power jack.
  4. You do not need to connect both GNDs from your Arduino to the motor driver. I would recommend connecting the one next to 5V to the logic side of the board

And now to the show-stopper problem: It looks like you are are not connecting anything to the PWM pin. It is pulled LOW by default, which keeps the motor driver off. Here is the relevant phrase from the product page:

Hope that helps!

- Ryan

Great! It works just fine now. I thought I could just do the PWM individually for each direction, but I get it now.

Thanks for the tips. I didn’t know the crimp connector housing came in single pieces. I will definitely start using those. And I will change the GND from the Arduino.

~A

I am glad you got it working. Thanks for letting me know. I hope you post some photos of your finished project when you get there. Good luck!

- Ryan