Hi,
I brought the Pololu High-Power Motor Driver 18v15 for my dc brushed motors at 11.1 V, and hooked it up with an arduino mega connecting PWM and DIR pins, and well as the FF1 and FF2 pins. When I then tried to make the motor move with a duty cycle of 50% with DIR HIGH, the motor made a strange whining sound and didn’t move, then when I put DIR to LOW, the motor was able to move. So I hooked up the motor to pure power only and it worked just fine for both directions. So the problem I have is that the DIR pin is apparently not functioning at HIGH for some reason? I checked the FF1 and FF2 pins, and they vary between saying that it is having a short circuit and overheating every few milliseconds when DIR is high (DIR LOW has no such problems). I’m wondering what has gone wrong with the motor driver or my setup and couldn’t find any online solutions, as a soldering problem doesn’t really make sense given that it works when DIR is LOW. I’ve attached a picture of my setup and i’d really appreciate it if you could tell me where I went wrong.
Thanks
Hello.
I am sorry you are having problems with your high-power motor driver. From the picture you posted, it looks like there are some wire strands coming out of OUTA. If any of those strands are making contact to V+, it could cause a short when OUTA is driving LOW. Could you try cleaning up that wiring to make sure that no stray wires are sticking out of the terminal blocks?
If that does not solve the problem, could you post the picture of your setup? (It looks like you unintentionally posted the same photo twice.) Could you also post a picture that clearly shows the components on the other side? What motor are you using? A datasheet or link to its specifications would be very helpful.
- Jeremy
Hi Jeremy,
Sorry for the late reply. I tried removing the stray wires and also I tried re-soldering parts that were close to ground. I will post a new picture soon, here’s the datasheet:
Thanks
313_RPM_HD_Precision_Planetary_Gearmotor_-_Specifications.pdf (674 KB)
We are still waiting for pictures. Did you have a chance to take them? Have you had any progress with the driver?
- Jeremy
Hi Jeremy,
Sorry about that, I thought that maybe if I soldered the motor wire ends it would prevent shorting but it didn’t work :(.
Here’s a photo of how my robot is set up, the motor driver is connected to the 11.1 V power source by two wires (attached to the white hub), the other MOTOR A and MOTOR B wires go to the motor itself which has 3 0.1 uF decoupling caps. The other two wires (DIR and PWM) are connected to an Arduino Mega.
Thanks,
Thank you for the additional photo. It looks like you have two motors in your system. What are you using to drive the other motor? If you are using another high-power motor driver, could you try swapping the two units and see if the problem follows the driver? It is unclear from your description if you are powering your Arduino Mega from the same power supply. If not, you should have the GND pins on the high-power motor driver and the Arduino connected. If you do not have this connection, could you make it and see if it helps?
- Jeremy
Aaaah, wow my bad haha. I had USB power connected to the Arduino Mega, and external power for the Mega was only used after it worked. Yes, connecting it by ground worked just fine haha. Sorry about that thanks for putting up with me.
