Noob question - Motor Drivers

I've recently got my Arduino and have been doing some pretty basic stuff with LEDs and some sensors. I have a bit of a grip when it comes to coding but nigh none about hardware. A couple of days ago a old fax machine at my company broke and, not justifying the cost of fixing it, I decided to salvage a few parts from it. On topic and to my question, I got two small stepper motors off it ( ), and I'm planning on doing a small robot with them, but everywhere I've looked for guidance people are using motor drivers to control motors. My question is, can I control the motors without using a driver and if so, what are the disadvantages? Thanks for any reply.

I'm pretty new to Arduino myself, and actually salvaged a bunch of motors from some old printers, so I have been trying to answer the same questions as you.

It all comes down to how much current and voltage are required to drive the motor. Even the smallest hobby motor probably draws more than the 40mA that you can get out of an Arduino pin, especially when it is stalled. You can drive brushed DC motors through standard transistors like the 2N2222 or TIP120 pretty easily, and there are other transistors for even higher current applications.

However, you will be limited in terms of what you can do. For instance, it will not be easy to drive the motor in both directions. For that you would want an H-bridge like the L298N, which is pretty popular. Steppers have the added complication of needing at least 2 'channels' (luckily the L298 is a dual bridge).

And even at that, you need flyback diodes and a bunch of other supporting hardware to managing things like back-EMF from the motors and isolating power supplies.

So the long and short is that you would probably do well to buy a motor driver if you want to play around. Once you have everything figured out you could always buy just the minimum discrete components (like the L298N) to implement in your final project.

Hope that helps.

Thanks for your reply. My problem is that I can't seem to find any of these components close to me so I was wondering if I could save me some hassle of doing it myself even if it involved some extra stuff. I'll try to see what I can dig up around my town.

I bought an L298N-based driver shield on eBay from China for about $12 with free shipping. Documentation is not very good and it took awhile to get to me, but seems to work (for the moment!).

Thanks for giving me the designation for the H-bridge, managed to find one relatively close for 6 euros, but not anything pre assembled, i might know of a place to look just waiting for a friend to get back to me.