Pure C Arduino

Practically with every project, I buy a new device - with which I need to familiarize myself. Most of the time those are devices using already very well known buses like I2C , OneWire or SPI . But from time to time it's a parallel device with a very specific interface. There's a need for the driver then. There are two ways: the easy one - get the driver from the internet and use it - now don't get me wrong that's a perfectly good way to solve the problem - your device is up and running pretty fast and you do not have to worry about it, since most of the problems have been already taken care for you. The hard way is to write the driver yourself. Now a question arise why to do it in the first place ? The are a couple of reasons for that. First of all - you want to learn something - most obviously you will, since you will have to learn about the device thoroughly. Second - you want to make it smaller/faster - that's more pragmatic reason, since the downloaded driver...