Arduino and two 3.0V DC motors

Hello guys. I really need your help. I'm trying to build a small three wheel with two 3.0V DC motors attached to the back of a square aluminium plate and in front is small wheel that is able to rotate for 360 degrees. I'm controlling it with Arduino Duemilanove Atmega168, but I can't get it to move. In my opinion motors are to week. I tried do something using cogwheels, but I don't have two of a kind nor they are available to me. Please help me, I have been dealing with this problem for more than a month now.

Have you measured the voltage at the motors? Presumably you are using some kind of driver chip, which may (depending on the technology) be losing a lot of your volts. If you have an L298 for example, and put 3 in , you'll only get about 1 out. To get 3 out, you need 5 in....

How are you powering the motors? Not from the Arduino I hope.

My driver chip is L293NE and I'm powering motors from Arduino setting the output pins on HIGH that is 5.0 V. I haven't measured the voltage at the motors since I don't have multimeter, but I'll borrow one from my friend and measure it.

You obviously have the Arduino i/o pins controlling the motors through the 293's inputs,but you definitely don't want to power the motors from the Atrduino. The motor output side of the 293 must have its own supply, although it's probably ok to run the logic side of the 293 from the Arduino.

Post a circuit so we can see where the 293 gets the motor power from.

Here is a picture of my prototype. You cano’t see everything very clear because my camera has only 7 megapixels, but I’m powering motors form Arduino. On the top of the breadboard is L293NE and the left side of it and first two diodes beneath are used as an H-brdige to control motor on left side. Same is on the right side of the L293NE and the lowest two diodes. I have checked the voltage across the motors and it is around 2.93 V.


wildbill: How are you powering the motors? Not from the Arduino I hope.

I'm powering motors form Arduino.

I have tried powering motors from 9V battery, but the construction still wont move. I thinking about using some gears, but I don't have any experience with that and don't know which sizes should I consider and how to putt it all together. Is there maybe some even better solution?

You need to get a battery holder like below and put some rechargeable batteries in it to power the motors.

But why should I use that since I couldn't get the construction to move with the 9V battery and the motors specifications are 3V?