I'm struggeling with a simple p-Channel Mosfet - controlling an LED.
It's basically this circuit:http://ruggedcircuits.com/html/circuit__28.html
The MOSFET im using is this:http://www.fairchildsemi.com/ds/FQ/FQP27P06.pdf
!!!The MOSFET in the given circuit is N-Channel - i changed mine accordingly (put the LED on the source-side of the MOSFET).
The Arduino is powered by USB - but has a common ground with the circuit.
The circuits V+ is 3.3V.
The code to drive the MOSFET is the Blink-Demo from the Arduino examples.
And here is the Problem:
When the Arduino triggers the MOSFET the Led changes their intensity (alternating to the debug Led on the Arduino -> p-channel has switched logic) correctly, but it never turns off completely!
As i can see the circuit does the job - but the Led still lights a tiny bit when in should be turned off. If i change the voltage, the brightness in the Led-off-State changes, too.
I found this problem in one other related Post - but no solution was given...can you help me to turn off my evil Led?