I’ve been using the mkrverse motor driver successfully with 12v DC geared motors from JSumo for a while now. I want to switch to 6v motors so I tried a couple - pretty much exactly the same as the 12v ones. Same setup/code. I am using an Arduino nano. I expected the motor to at least turn - nothing!
The motor is fine as I can test it with a battery.
i know I haven’t put a lot of info here but just wondered if there was anything obvious I was missing here!. I’m going to do some more testing and will update this post if I find any more info
Could be some part of your wiring that changed, or a current limit that is set too low? Do you have a multimeter handy to test the output of the motor driver with the motor plugged in?
Could you share a photo of how you’ve got everything hooked up? We might spot something
Here is a simplified version taking out my carrier board and just using a nano and the driver. Works fine with the JSumo 12v DC motor (250rpm). Doesn’t work with the GA25Y370SD-75 133rpm motor.
Hi Pete
What is with the 9V battery. That is not going to drive much in the way of motors.
Also you seem to have both motors connected at the same time (bottom pic).That will probably kill the battery as well as not really the right thing to do. One at a time is usually good fishing.
Cheers Bob
I normally use a 3S battery for the robot this is part of. That did exactly the same thing. The 9v isn’t ideal but should at least turn the shaft. In a previous version I used 4x AAs for similar motors. Worked fine with zero issues.
The 2 motors are not connected. Only 1 is. The two are in the photo for comparison.
Also the 9v battery drives the 12v motor fine.
Hi Pete
OK but it looked in the pic as if the 2 were connected.
I would also try the 4 AAAs. They will have a lot more short term grunt than the 9V. The 6V motor requires nearly twice the current of the 12V. It might be just enough to kill the 9V battery.
Are they the same current requirement but???
It is clear the set up worked before so it nearly has to be motor or battery.
Cheers Bob
Hi Pete
Just another thing. If you normally use a 3S battery why are you using a 6V motor. Or are you planning on reducing your supply to 6V.
cheers Bob
I honestly don’t know. The 6v motor should have turned with the 3S battery.
Makes sense that the 6v requires twice the current. Bit stupid I didn’t think of that. However I’m still stuck on why it doesn’t turn through the motor driver but is fine simply connected to the battery.
I might try an L298N tonight just for comparison
As I’ve got the N20 motors working, I’m going to print a wheel for it and try the sumobot with this arrangement. I’ve got several variants of the N20 with me (speeds)
The current requirements of each motor and the current available seem to be two large unknowns at play here. Has your current limiting trimming potentiometer been adjusted since you got the Makerverse driver module? The default from our factory is for no current limiting. If the current limit has been applied that could interfere, though I don’t think that is the primary issue here.
If you have a spec sheet for the 6V motors we should be able to confirm what kind of power supply ought to be able to drive them, the 9V battery seems optimistic to my intuition, I’m surprised it worked with the 12V motors at all.
Keep in mind a motor has its highest possible current draw as it is starting up so it will likely not turn at all, or run fine, no real in between.
Which is quite correct. That motor says a stall current of 3.4A which is going to be pretty much the start up current as it starts from stationary. If your supply can’t supply that there is a good chance it won’t start at all or your supply is shutting down under overcurrent conditions which is more likely. The driver you are using should be considered part of the supply.
Cheers Bob
PS. The stall current for the 12V motor is only 820mA (0.82A) which is about one quarter the 6V current. That could well be the difference.
Hi Pete
Just had a look at the specs on that IC controller
2A maximum and it looks like it shuts down on over current and resets when volts removed and re connected.
So could be your 6V motor start up may be shutting down the controller at start up.
Cheers Bob
