Let's Make Robots!

problems with L293D + Arduino

I wired up a L293D to my arduino, planning to run 2 motors with it, and just for testing I runned the blinkie program on it changing the LEDpin to the to the digital pin that goes to the l293d but only half of the pin works, like it turns in only one direction. Is it normal ?


It's 4 in the morning so I did not do a lot of trouble shooting, just changed the pins that were on PWM to digital, it didn't changed anything.

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First I used a 9v 300ma power supply, I tought it was that, then I used a 12volts 1.2 amp power supply it didn't change anything. I'll post you some pictures later.

I don't think it's the code since I use the test code you sent me, but I may be wrong... 

that lead us to some bad connection, or maybe a defective motor, have you changed the motors and checked if both are ok?

I've checked both of them with a 3 volt battery pack, I also reversed the pole just to be sure, everything's ok with those motors.

 Pictures coming soon...

I mounted everything on a protoboard now, no more breaboard, I uploaded the test code you gave me to my arduino, and there's only one motor spining, I checked the circuit everything looks fine, what's wrong?

Is it my arduino that is screwed up?

Or is it maybe  the circuit that is bad ?


 (btw, It was doing the same thing on the breadboard, I just thought that it was the code)

Omg, I managed to get the circuit working, the motors turning, thank you everybody!

I used a L293NE, it's the same thing execpt you need a couple of diodes, it works on the breadboard it's not the final thing but I'm so happy!

 It works! It works! It works!

And again thanks to anybody who helped me with this.

good!!    :D

I have my afternoon off tommorow, I'm gonna buy the new chip and a socket for it.


I've found a shop that sells the chip, so I won't have to pay like 10 bucks of shipping for one IC !


I'll send you news when the new circuit is done, hopefully tommorow.

I think i may have fried the chip...

When i soldered the chip to the protoboard, it heated a lot but i didn't worry thinking it was made to whitstand this temperature.

I had just plugged LEDs to the output pins, and now i've soldered my motors and they don't run...

sorry to hear that..  :(        you should use IC Sockets.

I have a 16 pin IC socket somewhere, but i was to lazy to search it...

And the chip costed me like 15 bucks because of the shipping.