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Hardware & Electronics

The most popular blog posts about hardware & electronics on Hacker News. 144 posts.

2014
94

Explanation of 44.1 kHz CD sampling rate

The CD sampling rate has to be larger than about 40 kHz to fulfill the Nyquist criterion that requires sampling at twice the maximum analog frequency, which is about 20 kHz for audio. The sampling frequency is chosen somewhat higher than the Nyquist rate since practical filters neede to prevent aliasing have a finite…

95

Douglas Adams's Mac IIfx

「99歳にもなったら入れる施設なんてあるのだろうか…」こんな悩みを抱えてはいませんか?現代社会は「少子高齢化社会」と呼ばれ、人口に占める高齢者の数が増えてきています。また、医療の発達により寿命はどんどん長くなっており、介護に関する悩みを抱える人も多いのではないでしょうか。

101

Designing and building a keyboard

Some years ago, I wanted to make a Nixie Tube clock from scratch. PCB manufacture was so expensive that I ended up just making the PCBs by hand. I figured I would give the market another look, and dang has custom PCB manufacture become cheap! The best/easiest service that I found was OSH Park. I'd never had PCBs made…

103

TCP/IP over audio

We present a simple to use implementation of networking across ultrasonic frequencies, by making use of Gnuradio and a microphone and speakers. This allows you to use TCP/IP , UDP across an audio link.