Can someone please tell me to control a motor using an arduino. I want to begin a robot project.
Can someone please tell me to control a motor using an arduino. I want to begin a robot project.
About Floppy and CD-ROM motors, there are few diferent ones there. For example center one (spinning the floppy and CD/DVD usualy it is BLDC motor). It is the hardest to controll motors in thies devices. manualy controll them it is bit hard. but in PCB there should be drivers. Not shure how the drivers are controled, but it shold be eacyer. by the way FLOPPY and CD-ROM BLDC (Brushless Direct Current) motors may be part of the PCB, because they usualy have Hall efect sensors to now the current possition. Then In floppy there is a SEPPER mottor moving the data reading head. it usualy has 4 wires. And they can be controlled by arduino, but you have to use some transistors or with STEPPER controller microchip. They make the weak arduino signal in tu strong one, sutable to drive the mottor. There is an explanation how to controll 6 wire and 4 wire STEPPER motor: http://nerdclub-uk.blogspot.com/2011/09/stepper-motor-control-2-phase-4-phase.html
Then in CD-ROM there is a regular DC motor with only 2 wires. They are the simplest to control. Just connect the pover (+ and - ) to the wires and it goes. If you swap the + and -, then it will go to the other side. Non revesable DC mottor speed controll with arduino and a transistor http://arduinoarts.com/2011/08/arduino-tutorial-f1-rc-car-dc-motor-driven-by-mos-transistor/ the potensiometer is just for telling arduino how fast you want it to go.
There are stepper mottor or 2x DC mottor controolers like this: http://www.ebay.com/itm/Stepper-Motor-Drive-Controller-Board-Module-L298N-for-arduino-NEW-good-/330808982986?pt=LH_DefaultDomain_0&hash=item4d05c07dca if you do not know how to use it, please ask. I like thies, because it is realy simpple and fast to controll small motors upt to 2A (look on the mottor or in its datasheet how much amps does it use).
And what type of mottors to use it depends on what the robot is going to do ant in what part. If it is for driving weals, it would be better tu use DC 
And for making bigger robot and controlling more powerfull robots I like this: http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/HB-25/List/0/SortField/4/ProductID/64/Default.aspx
It is realy powerfull one, hade acidently shorted the output, but it is still alive. 
we are using them in our robot:
This robot is made by KTU PI (Kaunas University of Technology Panevėžys Istitution) university students. Not the best robot, but it is our first on.
Ant this is a video how this robot can use webcam and computer vision application with OpenCV librray to detect an object, take it and bring it back 
By the way, in this video motors are replaced with more powerfull ones (from car windshield wipers) to drive outside
So just some fun stuff to get you more motivated to make your own robot
If this video is not working, then you can see it in youtube: http://www.youtube.com/watch?v=phI0wMpWMiE