Diagnosing MotorShield Trouble

Adafruit Ethernet, Motor, Proto, Wave, Datalogger, GPS Shields - etc!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
etiam
 
Posts: 2
Joined: Mon Apr 15, 2013 2:43 am

Diagnosing MotorShield Trouble

Post by etiam »

Hi. I assembled a motorshield and everything worked ok using a stepper motor (the $14 one
you guys sell) and the method where the power comes from the arduino and the jumper is
closed (using a 9V in). then i tried powering via the EXT_PWR connector, paying what i
thought was close attention to the polarity. perhaps i didn't though because now i get no
motor turning. measuring the DC output on the M3 and M4 i'm getting a steady ~8.48 on
all four lines where i was previously getting a modulating value in the 7VDC range.
anyway, could i have burnt out the L293D chips? they don't seem to be even moderately
warm to the touch anymore. the ardunio itself seems fine, it runs the basic blink code
fine. maybe i should run something more exhaustive?
thanks for any help.

User avatar
adafruit_support_bill
 
Posts: 88088
Joined: Sat Feb 07, 2009 10:11 am

Re: Diagnosing MotorShield Trouble

Post by adafruit_support_bill »

Reversing polarity can definitely burn out your L293D chips. In most cases the damage is limited to the L293Ds and the shield should operate fine once they are replaced.

etiam
 
Posts: 2
Joined: Mon Apr 15, 2013 2:43 am

Re: Diagnosing MotorShield Trouble

Post by etiam »

thanks. i've ordered some new L293D chips.

Locked
Please be positive and constructive with your questions and comments.

Return to “Arduino Shields from Adafruit”