Piezo Transducer or Transistor problem? please help.

[macmoy]

help.. i managed to do the drumset using parallel port. the problem is, i cant use the piezo properly.here how i do it.


i connect pin2(d1) of the parallel port to the COLLECTOR of the NPN transistor(BC548). then i connect the positive wire of the piezo to the BASE of the transistor. then i connect the ground to the EMITTER of the transistor. I also connect the negative wire of the piezo to the ground.

The problem is, when i hit the piezo,sometimes the PC reconizes the input,sometimes don't. I tested using a switch,it works perfectly.

So my guess is that the voltage of piezo that is giving the BASE is very low.
OR maybe the BASE of the transistor is expecting high voltage than a piezo can give.

so how will i solve this problem? please help me..

 

[macmoy]

PLEASE!! Anyone,please help me.

Please help me. I bought another NPN transistor(9013). but it doesnt change anything. please someone help me with this.
when i hit the transducer, it send voltage to the BASE of the transistor and the Pin2 of the Parallel port(which is in the COLLECTOR) will be connected to the GRound(the EMITTER).the data is sent to the PC and plays a SNARE DRUM.
The problem is,sometimes pin2 will be connected to the ground(play snare) BUT sometimes DO NOT!
When i replace the piezo transducer with a switch, it works perfectly.
I need to put the piezo transducer because the device that i am making is a digital electric drums. PLEASE. PLEASE.

Someone help me please.......