hi,
yeah thanks, but m fine now....
well....both are right but i think i confused you as usual....
1] LDR measures the ambient light
2] it is passed to PC using parallel port.
3] it is compared with preset voltages in the PC
4] the difference of the comparison is to be given to the LED using Serial port....
this is what is my query.....how to give the difference voltage to LED usig serial port?>??
you told me to connect to the circuit you gave to the DTR pin....but in that my question is what about the TxD pin i.ei data transfer pin??
i hope this makes sense now???