As small as possible motor driver

I want connect an ardiono board to a power source and 1 vibration motor. http://www.ebay.com/itm/10-PCS-14-3-5-mm-Coin-Pancake-Cell-Phone-Vibration-Vibrating-Micro-Motor-Robot-/171253403535?pt=LH_DefaultDomain_0&hash=item27df7f8f8f

  • I need the motor to vibrate for a few seconds every x minutes. For example every 15 min.
  • i need everything to be as small as possible.
  • ideal condition is the have it do this for about 12 hours.

Which board can i best use for this project? Any suggestions?

The smallest solution will be a surface mount driver (many exist for this sort of application, the hard part is finding one on a breakout board).

For instance this part would be suitable I think: http://uk.farnell.com/allegro-microsystems/a3901sejtr-t/motor-driv-full-bridge-400ma-dfn/dp/1651947

I imagine that this motor vibrates regardless of polarity of power you supply to it. This means you don't need a complex motor drive, just a switch to turn it on and off. You can easily drive it with a MOSFET transistor and maybe a flyback diode:

http://en.wikipedia.org/wiki/Flyback_diode

if you make all in SMT parts this should be very small http://learningaboutelectronics.com/Articles/Vibration-motor-circuit.php

If your just running the vibration motor, then a Arduino MINI with the transistor driver mounted on a "sandwich" board attached via standoff pins will make a total size of about 1 inch long and 3/4 inches wide and if use of SMTs then likely 1/2-3/4 inches deep.

Couple of little motor drivers here that would do nicely, for a couple of bucks. http://www.pololu.com/category/11/brushed-dc-motor-drivers

you don’t need a complex motor drive, just a switch to turn it on and off

Agreed. However, since the voltage is so low, a MOSFET isn’t really advantageous and a logic-level MOSFET is likely to be more expensive than a BJT. We don’t know what the amperage or winding resistance is of those motors, but the venerable 2N2222 is available in a surface mount package and should handle it no sweat.

However, SMT components can be frustratingly small if hand-soldered without experience. Some of those things are smaller than a grain of rice! On the other hand, a through hole resistor, transistor, and diode will still end up pretty darn small. They could even be soldered up inline on the negative motor lead and heat-shrunk. Hard to beat a boardless solution when there are volume constraints. :slight_smile:

Need to double check your coin motor, as most I have seen are 3V operation not 5V. So use of 5V drivers circuits would need adjusted down.

You might use the internals from the below servo.

http://www.hobbyking.com/hobbyking/store/__29547__HobbyKing_HK15318B_Low_Voltage_Micro_Servo_2_2g_11kg_08sec.html