A 9V block battery is totally unsuitable for powering motors - use a 9V power adapter with sufficient current rating, or a pack of AA batteries.
There is no shared ground: the motor driver must have a ground connection to the Arduino. Also the motor driver doesn't have a power supply for its internal logic, that's normally the same 5V supply as you use to power the Arduino (but didn't draw in that diagram).
Make sure you have the motor power connected to the correct pin: VMM is probably for the motors and VIN for the logic. Check the documentation of your specific module.
Don't forget: electricity is measured in voltage and current.
That a battery can deliver sufficient voltage (9V is indeed fine) doesn't mean it can deliver sufficient current (for motors that's typically somewhere in the range of 1-100A or more depending on the motor, and those PP9 batteries can do maybe 0.1 A before suffering from too much voltage drop).
Current: measuring the resistance of the coils gives you a good idea of the stall current (using Ohm's law).
Run the motors on a sufficiently powerful supply to measure the free running current, and the current under load (apply whatever load they're going to experience in the final project).
Speed: measure using an encoder attached to the motor, or external RPM meter (there are ones that you can point to a shaft with a clear dot on it, and will give you the rpm).
Torque: stall torque is quite easy to measure with a spring scale, torque when running is harder, it requires a torque sensor of sorts (e.g. a dyno/dynamometer).
Did I understand that you're running a motor rated for 6V off 9V? That's not a good idea, even with a PP3 battery which will be dead in no time anyway.
(Or does the full detail of the motor give a voltage range which goes as high as 9?)
No, I was testing it with a 9V battery connected to a 9V to 5V voltage regulator transistor.
Now, I am running a 6V 2500mah Lipo battery (I was just waiting for the shipping on this, that's why I tested it with a 9V)
codewriter123:
No, I was testing it with a 9V battery connected to a 9V to 5V voltage regulator transistor.
Now, I am running a 6V 2500mah Lipo battery (I was just waiting for the shipping on this, that's why I tested it with a 9V)
Is the Lipo connected directly to the motor circuit, or through the 5V regulator?
What is the part number of the 5V regulator?
Tom...
Railroader:
34 replies and still unclear what stuff is used...... Lots of helpers time used for nothing.
Unsubscribe is a likely outcome here.
Railroader, Look at my comment #16 and #29. I left the link and a picture of the one I'm using.
This test is only using the DRV8833, the arduino nano and a Dc motor, link below. I've posted the pictures before. I would love if you don't unsubscribe. All I want is some help and guidance. Thanks
DC MOTOR: 20.4:1 Metal Gearmotor 25Dx65L mm LP 6V with 48 CPR Encoder
Below on the pic are the specs of the motor. I was trying to test them and see if they match. That's where I was wanting some guidance.
6V is not high enough for the Nano's VIN pin, at least 6.6V is needed to get 5V from the voltage regulator. Lipos are 3.7V per cell and 2 in series (2S) will make 7.4V (about 8.4 when full charged). Do you have 3.7V Lipo batteries?
