Simple USB powered PIR sensor with LED attached to it (no arduino)
The circuit makes no sense to me. You should have 5V connected to the PIR's Vcc, the transistor is never going to conduct since its base is always above ground, there's no current limit on the LED and it emitter is above the collector. Don't you want an NPN transistor with its base connected to the output, and the LED and a resistor in series between Vcc and the transistor's collector, with the emitter connected to 0v? Something like that?