Go Down

Topic: L293B signaling problem (Read 526 times) previous topic - next topic

ironbot

Hi,
My L293B was functioning a year the right way. Newly, when I connected it to pwm 9pin of Arduino and digi-pins 7 and 8, it did not respond to flipping HIGH / LOW (didn't change direction). It all the time turns in one direction as if it can't see the signal is switched.

To test it, I first checked the pins: connected pin 7 to an LED, then setting HIGH/LOW, switched the LED on/off correctly. Next, I took GND and +5v of Arduino to a breadboard, then sent Enabling signal from Arduino pwm pin 9 to L293, but for commanding, plugged the Input A, B of chip directly to GND and 5v of Arduino on breadboard. Result: chip changed direction as expected!

I also measured the output of chip and I read that when I use GND and 5v of Arduino, I get +11.5 and -11.5 when flipping wires, from my 12v battery, so all ok. When I command from digi-pins 7 and 8 of Arduino, the measurement says +11.5 but never changes to -11.5!

I changed the chip with L293E: this behavior didn't repeat and the system worked ok.
So, is it enough to conclude that the Chip must be changed?

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy