Be able to change speed (not sure that’s even possible)
Not purchase another motor driver if one can be built with the components
Use Arduino (This is a must)
Use these particular brush-less motors (This is a requirement)
Note this passage from the motor website: “BEING ELECTRONICALLY COMMUTATED, THIS MOTOR WON'T WORK IF CONNECTED BY REVERSE POLARITY. NOTE ALSO THAT THIS VIBRATION MOTOR CAN NOT BE CONTROLLED BY PWM - IT MUST HAVE A STEADY 3V DC SUPPLY.”
My contact from Precision Micro-drives was kind enough to send me a drawing and a link to explain how he would do it using MOSFET, however I'm afraid this is out of my league and I'm in need of someone to explain how all the components are working and why etc.
I'm aware this is a big ask but I'm keen to learn, please make the assumption you are talking to a student as I have only a limited knowledge. This isn't for production, but so I can use the prototype to communicate with smartphones to test a couple of things (More my area, I work with code).
From my reading of the page you linked to, the motor requires a constant DC supply within quite a narrow voltage range, and does not make any provision for speed control. You can turn it on and off and that is all. If speed control is important to you then I suggest you contact the vendor and ask if there is any way to achieve it, for example by varying the supply voltage. I'm not optimistic that it will be possible.
To turn four motors on and off you can use any driver with four outputs capable of providing the voltage and current you need. Just about any dual h-bridge motor driver would do it. There are plenty of Arduino dual h-bridge motor shields, and you can even get Arduino clones with the driver integrated onto the main board which give you a much smaller and cheaper solution. But since the motors won't support pwm, all of these options will just turn the motors on and off.
vumbl:
You may ask but I must decline I'm afraid. This is mainly for testing the elements to the project.
Sure i understand it's for testing the main elements of the project ..
Well , it must be a secret , mysterious project that can't be revealed !!! 8) 8)
Pin 8 there is not PWM so you won't be able to control motor speed.
The signal from the PWM tells the mosfet/transistor to give the motor varying voltage depending on the speed.
mistergreen:
Pin 8 there is not PWM so you won't be able to control motor speed.
The signal from the PWM tells the mosfet/transistor to give the motor varying voltage depending on the speed.
Haven't we already established that the motors don't support pwm?
My contact from Precision Micro-drives was kind enough to send me a drawing and a link to explain how he would do it using MOSFET, however I'm afraid this is out of my league and I'm in need of someone to explain how all the components are working and why etc.
Haven't we already established that the motors don't support pwm?
The datasheet does state that but in the performance graph the voltage varies between 1.6 and 3.6 to show it's characteristics.
In the drawing provided the signal into the mosfet does infer it though. The OP did not provide the "link" so can it?
I would be tempted to try if I had a few extra . What happens to it if you do pwm it?
Got a pot to do a simple varying voltage setup? Does it work? Control the pot with a servo or get a digital pot.
