Duemilanove with motors?

Hi,

I know there's a motor shield, but it's $25 + dollars, about $20 too much. :)

Can I hook up something like a H-Bridge 1A motor driver? If not, what's a low cost way to hook up a Duemilanove to motors?

Thanks!

Depends on if you need bi-directional control or not. If just forward variable speed (or simple on/off) via a Arduino PWM output pin then a simple MOSFET power transistor will drive a DC motor just fine.

Lefty

If you do need a a low cost H-Bridge shield, you can get a kit here: http://www.nkcelectronics.com/freeduino-arduino-motor-control-shield-kit.html

$11 + $x shipping. Anything cheaper? Is there any way to just use a H-Bridge?

Re Lefty, not bi directional, can you give me a link as to what you're talking about?

Thanks.

Re Lefty, not bi directional, can you give me a link as to what you're talking about?

Here is an example for driving a solenoid coil. Just wire the motor winding in place of the solenoid. If you use a logic level MOSFET transistor you could eliminate OK1, R1 and R2 and drive the MOSFET gate directly with an Arduino output pin.

http://www.arduino.cc/playground/Learning/SolenoidTutorial

Sorry, I'm brand new to Arduino. Is there anything a bit simpler?

You can use this circuit: http://www.arduino.cc/playground/uploads/Learning/solenoid_driver.pdf Your motor will replace the Solenoid in diagram. Depending on the transistor, you may need to use 220 ohm resistor instead of the one shown.

Will a 2N3904 transistor work? I don't want to accidently fry my arduino.

It depends on how much current your motor draws.

The 3904 is kind of smallish, but for a (very) small DC motor it could be ok.

You need the diode in the schematic to protect your Arduino from back emf spikes from the motor, it is very important.

You need to check your motors currentdraw with the 3904 transistors datasheet to see if it can handle the current.

I would use one of the TIP type transistors, like TIP102 or TIP120.