UPDATE: I really appreciate your help! I´ve found the error, and it was a very basic one. I´m posting it here in case it helps someone out there in the future. I didn´t realised (I´m still learning), that you have to power up your arduino AND your motors separately! So Connecting the arduino to power supply (in my case a 9v adaptor, and then a 12v adaptor) didn´t help at all, because the motors have to get ANOTHER power source, in this case using the Vin pin connected to a positive row of the breadboard. Yes, I realise its a silly newbie mistake, but I wanted to go and write this down anyway. I didn´t undertand at first when people answering and commenting asked about what powered my motors... now I get it! THANKS!!!
About the squematics... I´m trying to get acquainted with circuitlab, because it is more complicated to understand -to me al least- than fritzing.
I´m not posting this as an answer because it is more than a clarification, and there are several comments already to post yet another one :)
I'm trying my first Arduino project, a Bluetooth controlled car. I've divided the project into two parts, one that connects the Arduino to Bluetooth and one that makes the DC motors work. I've found lots of tutorials, but I stuck with following one:
I've been reading a lot about Arduino and DC motors the last couple of weeks and I've tried some smaller things first (LEDs, buttons, light sensors etc). The problem here is that the motors are quite slow (the wheels won't even move when on the floor). I have an Arduino Mega and an Adafruit motor controller.
As I don't have a voltmeter right now I started to test without the motor sensor, because I thought that maybe it was consuming too much power. These are the tests results so far:
If I connect three AA batteries to both motors directely, they spin vividly, so I think there's no problem with them. The motors are two DC 4.5/6 V.
If I connect a 9V/1A DC adaptor, it's even worse: the motors won't move at all. I thought that maybe the adapter was faulty, but I've tried with another one. The second one is a DC adaptor 12V/1.5A center pin positive and the result is the same. No movement. The LED that I've added to the board for test purposes does light though.
I've attached those three AA batteries to the Arduino like the diagram below and it moves but oh so slowly!
I've added a simple alkaline 9V battery instead of the three AA (and I've put it together with the three AA too!) and the result is the same, no movement or very, very slow movement.
As the motors do spin I don't think that I've set the pins incorrectly or that the code isn't working but I fail to understand why this is happening?
UPDATE: Sorry about the diagram (I havent posted it, but I did provide the link though). Im new to the arduino and thought that was the kind of diagram that it should be posted. What should I attach instead?