Sunday, April 26, 2009

Was reddited, some replies and comments

Yeah, so my previous two posts ended up on reddit and gizmodo, and got a fair amount of comments. Thank you for the 15 minutes of fame. It will naturally all go to my head, and I'll be expecting flamboyant Sovieteqsue monuments to be built depicting myself at any moment. ... On a more serious note, I figured I ought to reply to some of the comments I got here and on various other places:

Several people suggested that one could simply just pipe the data to the soundcard, like this
cat data > /dev/dsp
and then on the receiving end simply
cat /dev/dsp > data
In an ideal environment with no noise, no echoes and with hardware that has a completely ideal acoustic properties, this would probably work if you started broad casting and receiving at exactly the same moment. In the real world, all it does is produce a lot of noise.

Other people were upset over the fact that I did not use the best possible algorithms, suggesting that Fourier transforms is CPU intensive and I got crappy baud rate. This is all true, I could have used impulse response filters and gotten hundreds of kbps in speed out of it. But creating a high speed software modem wasn't the mission (and I never presented it as such). It was a hack, for the fun of it. What they are saying is basically that MacGyver would have been more effective if he simply carried a gun. He would unfortunately also have been no where near as entertaining to watch. I deliberately chose crude components (such as a DFTs filter instead of a FFT filter or a FIR filter) and simple algorithms to make it understandable for people who don't have degrees in signal processing.

Then there were the people that suggested I simply connected the two computers with male-male audio cables. This would have worked too. But I avoided this because of two reasons. The first reason is that I didn't have any cables of that nature laying about, and the second is that the laptop isn't grounded, which means that the stationary computer and the laptops don't share a common ground. Static buildup in the laptop might lead to a power surge upon connecting it to the laptop, that potentially could damage both of the computers, especially given the low end nature of laptop sound cards.

1 comment:

1. The sound card idea was thoroughly entertaining to read. Most of the rest of your posts are as well. I hope you keep it up!

~Anon