Mood light made of a LED lantern

A quick and dirty afternoon project.

YM2149 and MIDI

I’m still working on my YM2149 synth project.

YM2149 sound generator, Arduino and fast pin switching

I spent my childhood with an Atari STe and its bleepy sounds. Recently, I purchased its sound generator on eBay: the YM2149 chip (made by Yamaha) or the AY-3-8910 (made by General Instruments).

I would like to make a chiptune MIDI synthesizer with it, but I thought it was a good start to play existing tunes.

Sharing Links Physically

Why should we only share things we like on Facebook, Twitter or by email?

I’ve imagined a fun application with one of these small thermal printers. Although these printers are really Arduino friendly I coded a .Net class to use them directly with a computer. Then, I made a simple Safari extension which allows to print the URL of the current page… with a QR Code, of course!

The width of a paper roll is perfect for this purpose, and giving a piece of paper to share a link might be quite fun.

This extension sends a command to a small server app which is a background service connected to the printer. It’s not perfect, I’ve made it rather quickly, but it works fine.

I used the MessagingToolkit’s QR Code open source library. Ok, let’s have a look at it.

Thermal printers and (cheap) power supplies

Why does a thermal printer need a good power supply?

Because heating dots need a lot of power! With my cheap ’5V – 2A’ wall transformer, here is what happens to the supply voltage when I print a picture.

ESC/POS Thermal Printer and Mono (or .Net)

Recently, I found small thermal printers sold online, like the Sparkfun’s one. (You may find these en eBay too.)  To communicate with these printers you will need a serial link, working at TTL levels.

I saw an Arduino lib on Blidr blog, but I’ve got a standard FTDI board and I wanted my printer to work with it.

So, I made ThermalDotNet: a .Net class to use these thermal printers.