Florentin von Frankenberg

mc9s12dt256b drawing too much current?

Discussion created by Florentin von Frankenberg on Jun 6, 2009
Latest reply on Jun 6, 2009 by kef

I am powering my hcs12 through the 2.1 mm barrel connector, and have it protected by a 250 mA fuse. The manual says not to power external circuitry with more than 250 mA. I have most of the GPIO pins and PWM pins sending signals, but nothing that requires any substantial power. Port A, and T are being used to control external ICs (quadrature encoder counter chips, and the motor drivers) and 4 of the PWM pins are being used to control my motor drivers. For some reason, my fuse keeps blowing. The microcontroller is drawing more than 250mA. Is it possible that this is a result of "normal" operation? Or is my problem more likely bad wiring somewhere.

Note: The serial port is also being used to send and receive messages and a couple of the other pins (J6, J7) are being used to read switches' values.

-Concerned in Toronto