ive been soldering arduino nano to prototype half boards with L293D
so far ive built 3 boards they work great but ive been stuck on the fourth and rebuilt it 5 times with the same problem ending as a result
im using a rechargeable 7.4v 2000mah battery
and 2 pololu 6 v hp motors
the problem being the motors connected to the L293D run slower at about half the speed than my other 3 prototype boards
im using the same sketch as the other 3
why is this ?
am i losing current somewhere?
anyone experience something like this?
thanks for the help
Bad motors. Bad or uncharged battery. Bad connections somewhere.
If you have a multimeter, trying measuring battery voltage and voltage across each motor when the code is trying to run them at full speed. If you don't have a multimeter, it's time to get one.
Hi steve
The motors work good with my other boards and the battery works as well
So that leaves bad connections So using the multimeter the L293D motor voltage is 4.47 V As oposed to my other boards they are 7.4v So now my question is how can i find the problem if its a bad connection Im kind if a newbie in this field
It appears to work as expected. I would suggest you read the L293D datasheet and remember the voltage drop is X2 as you are driving two motor phases. A schematic would be much easier to follow then the frizzy thing you show. It needs all the power and ground connections shown. The prototype boards you show are notorious for bad connections.
gilshultz:
It appears to work as expected. I would suggest you read the L293D datasheet and remember the voltage drop is X2 as you are driving two motor phases. A schematic would be much easier to follow then the frizzy thing you show. It needs all the power and ground connections shown. The prototype boards you show are notorious for bad connections.
Hi
Here is the schematic
The thing is with my 3 other boards i appear not to havve any voltage drop
I checked the nano board and every connection it seems to be working fine
The only difference is
The L293D at 4.5 V at the negative and positive for thhe motors
As oposed to my other 3 boards they are at 7.4 v which explains why this board runs my motors so slow
So im thinking tbe L293D may be faulty and may cause a voltage drop?
Nice schematic! Best one I have ever seen done in Fritzing, hands down.
I don't see how your LED will ever turn on, you need to flip it 180 so that D11 driving high will turn it on.
As drawn, D11 going high will reverse bias the LED and it will not turn on, and D11 low will put a low on both sides of the LED and it will not turn on.
There does not seem to be any power source connected to Vin - what source are you using the Nano and the motor driver?
Hi thank you for your reply
As you can see in the photo the Vin is connectted to the positive of the circuit board
And about the led it works fine
I have it hooked up from D11 to a 100 ohm resistor linked to the negative on the circuit board
Thanks for your concern
However my L293D's are cheap knock offs could thatt be the problem?
And thanks for the compliment about the schematic
Yeah it took me a while to make it
Hi
The joints are perfectly soldered each side
I desoldered the L293D and keep trying other ones i got a whole bag of lnock offs
Yet i get the same voltage of 4.95V
Where it actually should be 7.4v
And funny thing is you were talking about the VIN
well somehow after i switched to another L293D
The VIN started shorting
Again another problem. I camt wrap my head around
It wasnt shorting all this time and the soldering is perfectly done i really took my time doing it
Could these gikFun boards be faulty+?
