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11 years, 7 months ago. This question has been closed. Reason: found an answer.
Burnt mbed?
I was driving a motor (through a L298 motor driver) using my mbed. Due to over current L298 was burnt and in that moment mbed also stopped working. I removed and re-plugged the mbed but even the status led is not working now. Has the mbed burnt? How can I check it? (I was using pin 25 and 26 as PwmOut s)
1 Answer
11 years, 7 months ago.
I am assuming the motor was driven from more then 9 Volts,
then if there was a path through L298 for the >9 Volts to flow, then the LPC1768 will be severely damaged.
If the blue LED does not come on then the MAGIC chip is possibly dead.
I would make sure you have about 5 Volts on pin 39,
3.3 Volts on pin 40,
also the TWO voltage regulators, should be, GND 3V3 4V5 - 4V5 3V3 GND
one of the powers the MBED, the other powers your electronics.
Hope that helps,
Ceri
yes, motor was a 24V one. when power is supplied pin 40 and 39 shows 3.3V and 5V. but the other regulator's 3.3V output pin shows it is short circuited with the ground. even after I removed the regulator and checked those points are connected.
posted by 16 Jan 2014there is a SMALL possibility that you have just destroyed the LPC1768, if you use a very sharp scalpel and run it along the joint between ic legs and body slowly, and gentaly several dozen times, then you can detach the plastic part, double check no shorts, if then you have 3V3 on regulator,and a drive on PC. you can put a new LPC1768 down, I have done it before, so it is doable
CERI
posted by 16 Jan 2014
I know it's too late now, but in the future you may want to consider using opto-couplers when driving high voltage peripherals, they could help you save on replacing an mbed. Dave.
posted by David Fletcher 15 Jan 2014