25 pin rs232 is exactly the same as 9 pin - it just has a bunch of unconnected pins. Maybe you should investigate using the parallel port - it's a lot easier. LOOKS EXACTLY WHAT YOU NEED and if your PC has a serial port it's likely to have parallel.

waaa. i can't understand.
there is a rs232 d-25(25pins) is this also the parallel port?
because, the pin information is different on the site that you gave.

by the way, i think, i'll stick to rs232 9pins.

please answer me: How can I send data physically to the PC? it depends on the voltage that is running in the receive data pin right? how can i manage that voltage? how will i know the time to send the next bit?

i think i can use UART? but how to use it physically? i mean, can anyone tell me what wire to put in its pins? do i need battery? where can i get the timing to send the next bit?

please help.

try to look at this video.


i think that is what i want to accomplish.

please help me..

is it posible to send bits(1startbit,7databits,1stopbit) without UART?

If yes, How will i know when to send the next bit?

e.g.
send startbit

when will i send the 1st data bit? what is the signal that will tell me to send the second bit?

PLEASE HELP me.. please.. please..

I have read something that there is a clock line.
when the clock line is HIGH/"1"/-3volts then signal in the RD is a bit.

so where can i find the clock line? is it thr RTS of the pc?
the RTS is high if the pc is reading the bit I sent? then RTS is low if done reading the bit and time for me to send my next bit?
Am i thinking correctly? please,someone help me. PLEASE.

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 it that the voltage of piezo that is giving then 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..