I was figuring some sort of really slow morse code (not the real morse code) but very similar except done in binary and each dash and dot is elongated time wise.Brynet-Inc wrote:Sorry for the off topic reply inflater..Kevin McGuire wrote:I know a goal of mine.. one day.. is to get a circuit built where I can transmit some data (very slowly) using the parallel port over the air. I have built a small RF oscillator using a 1MHZ crystal and transmitted audio over it, but I still need to adapt it to two computers and a small chat program does have some interesting usage.
@McGuire, That sounds pretty cool.. A friend of mine many years ago actually build something similar onto two older laptops.
It was rather neat, Like low-tech Wifi!, I'm even fairly sure he managed to do file transfers over AM or FM radio..
(I don't remember how.. but I think there was some sort of conversion process involved due to the possible corruptions?)
I myself would like to build a similar RF linkup between two computers.. Some day.
I think a cheapo way to do it would be to build:
1. A sound generator with a 555 timer.
2. The 1MHZ oscillator.
Then couple 1 onto 2 using a NPN transistor. Then build a receiver and demodulate the signal (AM) with a diode then feed this into the other computer sound card. Write a little program to open the sound recording device and use a FFT at a certain interval to determine if the signal is there. I think also switching the signal on and off by using another NPN to turn the power on and off to the 555 with the parallel port would work.
I have my one megahertz oscillator down on a board. If I can muster up enough strength to try working on a receiver then I might come closer to doing it. For I have only recently after two to four years been able to actually build a oscillator let along a receiver. It might sound easy but it is not at all. I really need a oscilloscope.