Simpliest Arduino TT wheel motor

Hello,
I just purchased Arduino TT wheel motor(pic below):

and have no idea how to use it ( well, I have, but it seems its not the right way). Could somebody explain how could I use this motor just to make it run?

Hi,

It's a DC motor that runs just by connecting it to a DC source like batteries, a DC coupler (cellular charging ones) or whatever that gives DC current.

If you reverse polarity (change the cables) it will run the other direction (clockwise, counterclockwise).

Basically, the higher the voltage the faster it runs, but speed is not exactly linear (if at 3 Volts the motor runs at, say, 100 r.p.m., at 6 Volt it will not run at 200 r.p.m, -although for not big ranges you can assume certain linearity). I'm using one like this and never connected it above 12 volts. Up to this voltage it runs without burning itself (and without heating up).

Using an arduino the best way to generate a DC variable voltage are the digital outputs, using them as a Power Width Modulator output (PWM: consider them as a DC source which value you can control in 255 steps from 0 to the maximum voltage -see later) From a naked arduino you will not get a serious response: the motor will run slowly, with a minimum variation (even if you change PWM) and, the worst, you can damage the arduino.

You have to use a motor shield, that is a card that boosts the PWM signal and that gives more strength to it compared to the one that the arduino generates. Then, the motor runs accordingly to the signal given by the arduino (PWM) but taken the power from the other DC source that you have to connect to the shield to supply it. Once again, the bigger the voltage the faster the motor will run for a same PWM signal.

I'm using an Arduino motor shield. There are others you can choose from.

Regards

vffgaston:
Hi,

It's a DC motor that runs just by connecting it to a DC source like batteries, a DC coupler (cellular charging ones) or whatever that gives DC current.

If you reverse polarity (change the cables) it will run the other direction (clockwise, counterclockwise).

Basically, the higher the voltage the faster it runs, but speed is not exactly linear (if at 3 Volts the motor runs at, say, 100 r.p.m., at 6 Volt it will not run at 200 r.p.m, -although for not big ranges you can assume certain linearity). I'm using one like this and never connected it above 12 volts. Up to this voltage it runs without burning itself (and without heating up).

Using an arduino the best way to generate a DC variable voltage are the digital outputs, using them as a Power Width Modulator output (PWM: consider them as a DC source which value you can control in 255 steps from 0 to the maximum voltage -see later) From a naked arduino you will not get a serious response: the motor will run slowly, with a minimum variation (even if you change PWM) and, the worst, you can damage the arduino.

You have to use a motor shield, that is a card that boosts the PWM signal and that gives more strength to it compared to the one that the arduino generates. Then, the motor runs accordingly to the signal given by the arduino (PWM) but taken the power from the other DC source that you have to connect to the shield to supply it. Once again, the bigger the voltage the faster the motor will run for a same PWM signal.

I'm using an Arduino motor shield. There are others you can choose from.

Regards

Thank you for the information. So, I cannot use DC motor without addition power supply. Is there no way to run DC motor at very slow speed only using Arduino's built in power supply?

justafailure:
Thank you for the information. So, I cannot use DC motor without addition power supply. Is there no way to run DC motor at very slow speed only using Arduino’s built in power supply?

NO repeat NO. You must have something to interface between the Arduino and the motor. The Arduino pins can only produce about 20 milliamps and while the Arduino 5v pin can provide more current it can’t power a motor.

If you look (for example) on the Sparkfun or Pololu websites you will see lots of options for DC motor drivers.

…R

All clear now. Thanks.

Is there no way to run DC motor at very slow speed only using Arduino's built in power supply?

Not using the onboard 5V regulator but it is feasible to have a uController programmable power supply that takes a command from the arduino and outputs a specific voltage. Using an LM317 adjustable regulator and either digital pots or analog switches and resistors that can be switched in parallel to change the adjust voltage that is normally done with a 3k to 5K potentiometer. I have the analog switches (ADG511BR) and the surface mount to DIP adaptor and resistors to do this. If I went to Fry's and bought the LM317 adjustable regulator I could have a programmable power supply by lunchtime. Switching resistors in parallel with each other lowers the total resistance. The analog switches are designed to be controlled with a TTL 5V Logic signal so the design is extremely simple and guaranteed to work every time. It's not any kind of exotic circuit so any Newbie could implement it if they could solder the surface mount chips onto the DIP carrier. That would probably be the only show stopper for some people because the pins are very close to each other. If you can find an anolog switch in a DIP package then you could do it. It seems they don't make DIPs any more but China has a ton of old surplus chips they bought from the us during the past 20 years and are not selling back to us on ebay one by one. (a 5 cent 14 pin chip sells for $2. go figure)