3V-5V (22MA at 3V) motor, control directly with PWM

Hey,

Can I control a 3V-5V (22mA at 3V) Coreless DC motor directly with PWM from the analog pins? I'm powering my arduino nano from external power.

If not, than how? (The most small and minimized solution please, i'm trying to keep it all very small)

I want it to run at 5V for max speed and lowest speed to be determined (I still haven't received my motor so i'll check the minimum voltage for the motor to spin)

Thanks!

Can I control a 3V-5V (22mA at 3V) Coreless DC motor directly with PWM from the analog pins?

Maybe but I would not chance it. Also, you will not have direction control.

If not, than how? (The most small and minimized solution please, i'm trying to keep it all very small)

https://www.sparkfun.com/products/9457

Its small (less then 1in x 1in), cheap and effective!

dan252: Hey,

Can I control a 3V-5V (22mA at 3V) Coreless DC motor directly with PWM from the analog pins? I'm powering my arduino nano from external power.

If not, than how? (The most small and minimized solution please, i'm trying to keep it all very small)

I want it to run at 5V for max speed and lowest speed to be determined (I still haven't received my motor so i'll check the minimum voltage for the motor to spin)

Thanks!

22mA at no-load, or 22mA stall-current? You need to make sure the motor cannot take more than about 30mA stall to be compatible with Arduino outputs, and you must add flyback diodes too (preferably schottky ones to keep current right away from the built-in protection diodes (which aren't rated for anything like 22mA).

Its very rare indeed to find a motor with a stall current less than 40mA, it implies a tiny motor with very high resistance windings.

[quote author=Drew Davis link=topic=181090.msg1342175#msg1342175 date=1375643972] https://www.sparkfun.com/products/9457

Its small (less then 1in x 1in), cheap and effective! [/quote] that is not very cheap for me.. another option?

p.s. no need for direction control

MarkT: 22mA at no-load, or 22mA stall-current? You need to make sure the motor cannot take more than about 30mA stall to be compatible with Arduino outputs, and you must add flyback diodes too (preferably schottky ones to keep current right away from the built-in protection diodes (which aren't rated for anything like 22mA).

Its very rare indeed to find a motor with a stall current less than 40mA, it implies a tiny motor with very high resistance windings.

I can't find that info, I bought these motors (http://www.ebay.com/itm/10pcs-6-12mm-Coreless-Motor-Aircraft-Motor-Helicopter-Motor-High-speed-Motor-/180954544362?pt=Radio_Control_Parts_Accessories&hash=item2a21bb38ea). I'm quite the beginner so can you please explain what are schottky flyback diodes and why I need to use them?

Thanks for answering~!

EDIT: I don't want to use another battery, i'm powering the arduino nano with a 7.4v 2S Li-Po battery.

Why you need a fly back diode… http://en.wikipedia.org/wiki/Flyback_diode

Wear to get them https://www.sparkfun.com/products/10926

As far as motor drivers go $10 dollars is a good deal for a pre made one. You can make one your self but I't will not be as small. Size always comes at a cost.

Edit: you could use a transistor… (no direction control) http://bildr.org/2012/03/rfp30n06le-arduino/ https://www.sparkfun.com/products/10213

[quote author=Drew Davis link=topic=181090.msg1342422#msg1342422 date=1375658924] Why you need a fly back diode… http://en.wikipedia.org/wiki/Flyback_diode

Wear to get them https://www.sparkfun.com/products/10926

As far as motor drivers go $10 dollars is a good deal for a pre made one. You can make one your self but I't will not be as small. Size always comes at a cost.

Edit: you could use a transistor… (no direction control) http://bildr.org/2012/03/rfp30n06le-arduino/ https://www.sparkfun.com/products/10213 [/quote]

Hey, i need to control 4 motors of this kind, so 20$ is too much for me, I can't use the transistor and diode because it will fall apart, it should be in a tiny UAV that flies quite fast.. I need a board of some kind (like the one for the 2 motors, but for 4, and if possible more cheap)

Many Thanks!

ULN2803? 8 transistors and diodes in one package.

It will be hard to find a pre made board that controls 4 motors… chances are you will have to buy two H-bridges. If the transistor idea does not work out, that motor driver is your cheapest option. Also, why would they fall apart?

[quote author=Drew Davis link=topic=181090.msg1342987#msg1342987 date=1375706619] It will be hard to find a pre made board that controls 4 motors… chances are you will have to buy two H-bridges. If the transistor idea does not work out, that motor driver is your cheapest option. Also, why would they fall apart? [/quote]

Not true, H-bridges are not needed here, you missed the OP's comment:

p.s. no need for direction control

A board with an ULN2803 octal darlington would work (and also reduce 5V down to about 3V as it happens).

You want to drive 4 motors, only one direction? How about the SN754410 Quad Half H-Bridge ? You don't need an H-Bridge, but looks like this little IC, can drive 4, and cost only $2.35 at https://www.sparkfun.com/products/315

Not true, H-bridges are not needed here, you missed the OP's comment:

I have looked and have yet to see a board that is able to control 4 motors for under $20. Remember he thinks if he builds some thing it will fall apart for some reason. Also, if you do manage to find a board like that it will probably be more heavy which is not good for a Tiny UAV!

I have looked and have yet to see a board that is able to control 4 motors for under $20. Remember he thinks if he builds some thing it will fall apart for some reason. Also, if you do manage to find a board like that it will probably be more heavy which is not good for a Tiny UAV!

The link I provided is to an IC, not a board, and on the link it's price is well under $20. The little IC should not be heavy. And it can control 4 motors if only one direction is needed. Or at least that is how I understand it. I could be wrong (again) LOL

Sorry for the general use of the word board. Your right it is an IC, but it is not Pre-made in the sense that it currently has no way to connect to his motors. He will have to make a PCB, Use a breadboard, or try and solder the connections on to the pins. According to his earlier post he seams to think that if he builds anything that it will fall apart for some reason. That being said unless he wants to pick up a soldering iron, he does not really have many cheap options.

What are you thinking dan252?

Could you please provide a little bit more detail about your project , what you are doing and how you are doing it ... solutions can change based on that information.

Thanks