Pure C Arduino

Recently I wrote a driver for a nokia 3310 (pcd8544 based) lcd display which I had lying around.Again, I decided to create my own driver just to learn something about it and to see how much effort it will require - turned out that this driver is pretty easy to handle. Despite the fact that it's suggested to use 3V3 logic (maximum accepted voltage accordingly to the datasheet it's 7V), it works great with arduino powered with 5V and using 5V logic outputs. Adafruit's Library I had a look on Adafruit's library for that display just as a reference ( github ) and it seems very primitive to be honest - it allocates a huge display buffer without asking the user whether it is really needed (it consumes more than 25% of available RAM on Arduino) and what's even worse it uses bit banged SPI to communicate with the display. Why ? Why bother when there is fast & reliable hardware bus available on that MCU (and of course like all Arduino IDE libraries it's writte...

A(rduino)OS (AOS) is an attempt to write a simple pre-emptive scheduler - mostly to learn about how such system works but it's a fully functional implementation which can be used in a practical way good as well. First of all, if you have no theoretical background about context switching I would recommend to have a look on a great description regarding schedulers published by avrfreaks: Multitasking on an AVR AOS depends on libpca - it uses some routines from it in order to avoid code duplication. It is completely written in C from scratch with a little of assembler (in order to realize context switching). It comes with a documentation and some examples as well, which is hosted along with the repository on github: AOS Doxygen documentation Overview Most of the pre-emptive schedulers (besides cooperative schedulers) is implements and is driven around a "tick" - an interrupt which happens periodically with a programmed frequency and which is responsible fo...