nice
Nice board!
I thought the L293D chip is actually 4 independent sets of 4 pins where each V+ pin provides power for one of the motor outputs. You have regulated power to 3 of them and unregulated power to one. Why is that?
This is the diagram as the chip is connected on the picaxe 28 board. As you can see, all V pins are connected to V2
I just found this tuto, it’s
I just found this tuto, it’s really great thanks! I have a L293D that doesn’t fit in my 18x project board, but now thanks to you it won’t be useless 
**Great L293D motor driver **
tutorial mate, id been battling for ages trying to think of a decent way to integrate a power supply with the motor driver, but my electronic skills are a little lacking at the moment. Im gonna try and make one this evening for guilbot. Will post a pic and say thanks later 
Check the datasheet for the
Check the datasheet for the L293D. You’ll see pin 16 is Vcc1 logic power, and pin 8 is Vcc2 motor power, with pin 1 being the enables to 2 outputs and pin 9 being the enable for the other 2 outputs. Pins 1 and 9 generally are spec’d as 5 volt logic inputs, not power, and the Vcc1 logic power should also be 5 volts. Vcc2 can be anything from the level of Vcc1 on up to 36 volts.
How about that. I build
How about that. I build edward from the schematics in the picaxe manuals. I just figured the 5V indications where a typo. Edward runs 7.2V on all corners of the motor driver chip and it still works.
Well, I wont make another board without first checking all the real datasheets properly.
Good solid info but a question if I may?
Can I ‘stack’ these chips , put several on top of each, soldering pin1 to pin1 etc to boost the current output?
Just a quick ‘dirty thought’ for Mr Basic
Pete
I need Help!
so. i build the circuit on my breadboard. The easy one only works, if the upper connection from pin1 to pin16 on the L293D is Not connectet. otherwise the motors only drive forward. so today i tried to build the correct implementation but it is still not working until i pull the capacitor on pin16 out of the breadboard.
The Red "Dot" is the place where the capacitor should be. But when he is there the motors only beep. did i something wrong?
a.. why is on the pcb two more capacitors and a voltage regulator?
Do you have made connections
Do you have made connections between the upper and lower Power and GND rails. These are normally not connected internally.
The voltage regulator in guibots schematic is only for a separate power supply for servo motors.
Thats the Problem! I can’t.
Thats the Problem! I can’t. if i connect the upper gnd to the lower gnd… it’s ok and everything is working but when connecting the upper 5V to the lower 5V the motors only work in one direction. and if i don’t remove the capacitor (red marked in the picture) the motors are only peeping.
Why there are 2 capacitors? when i remove the 100µF-capacitor and the 5V-5V-connection it works. but is it right!?!?
Did you check the polarity
Did you check the polarity of the capacitor?
The L293D has 2 Power supply pins. Pin8 is normally used for the unregulated motor power supply (directly from the battery). Pin16 is for the regulated (5V) logic power supply. You can also use a single regulated power supply for both, this is not recommended, but for testing its should be ok.
For a real robot you should supply power to the Arduino board over the external power connector from a battery. The unregulated battery power is than available on Pin Vin on the Arduino.
yes the polarity is right.
yes the polarity is right. i’ve replaced the 100µF to a 0,1µF Capacitor and now its running unless you connect pin1 to pin16??? i don’t know.
I even don’t know what is
I even don’t know what is wrong with your schematic. Maybe you better take a look for the Aduino motor sheet. This is more Arduino specific. Arduino - ArduinoMotorShield or http://blushingboy.net/p/motorShieldV3/
Yo don’t need a voltage regulator. You can use the internal Arduino regulated power for the L293 logic.
Hello Edgee, sorry for the
Hello Edgee, sorry for the dealy answering to your comment, my email box has been chaotic since I’ve been on vacation… Good to know you find this tip useful 
Did you manage to build your motor driver already?
Did you tried without the caps?
Did you tried without the caps? How does the motors work without the caps. Try first without the caps and then you can try with the caps, this is easier to debug.
The voltage reg is… if you motors runs at 6v you should connect your power source (battery) directly to the pin8. Then because your microcontroller (Arduino) and the chip L293D operates at 5V you should power them with 5v. This is where the voltage reg comes in.
let’s take the following case scenario:
9V little battery powers the arduino through the power plug. You connect the pin1, 8, and 16 on the L293D with the 5V that comes out from the arduino.
Then your motors operate at 7.2V, you connect V+ from the 7.2V battery to the pin8 on the L293D and then you have to connect the GROUND of that battery to the rest of your circuit.
hope this helps
Same problem
. Without the caps its the same thing. it only works with one motor. if you connect both they only drive one directon and stop. but they sould both drive 4times in different directions and then stop. on the serial monitor you can see Forward Backward forward backward. while it is writing backward the motors stop and during forward they work. hm. did i understand it right: i have to connect a batterie (6V or whatever the motors need) between pin8 of L293d and V+?
Thanx
"… i have to connect a
"… i have to connect a batterie (6V or whatever the motors need) between pin8 of L293d and V+? …"
The battery power goes DIRECTLY to the pin8, nothing else here.
Than the other pins on the L293D gets regulated power (5V from the arduino or from an external voltage regulator)
You have to check what are your motors needs.
How are you powering the motors and the circuit??
i connect everything like on
i connect everything like on the first breadboard-picture.
whit one motor everything is ok. but with two there is this problem. and i dont think it is the batterie cause it works but not in different ways… together they drive in the same direction but in diffent ways not. in the serial monitor left and right doesnt appear ???
how are you powering your
how are you powering your motors and microcontroller?
Tomorow I will buy a
Tomorow I will buy a batterie case… then I can give you more information… until now i only powered the µC over usb… is this a fault?
