I've set up an 16F84 to drive a DC motor. In order to do that I've hooked up an 330ohms resistor to the base of an BC368. Its emitter goes directly to ground and the motor is wired with a protection diode to Vcc - 5V. When attaching a LED instead of the motor, it works fine.

When I drive the otput to high, it seems like the device gets reset. I've noticed a little voltage swing when it turns on. Further I've noticed that the port doesn't go all the way to Vcc, instead of 5V output, I get 3,5V to the resistor. But there isn't any overload of the port either, it can't get that much through a 330oms resistor. I can't figure out why it doesn't work.

The only thing I can think of is that the port short circuit the Vcc to Gnd... I've tried several µC and I've wired it both on a PCB and with wires.

I've put up a schematic here. http://home.sol.no/~ssemjaco/images/problem.gif The voltage regulator is set up to output 3V (other resistors than in the schematic), but it acts all the same on 5V (notice: "LF" PIC)

Regards
Stein Sem-Jacobsen