If you spend any time playing with Arduinos, ATtinys or looking at AVR spec sheets, you soon encounter a bewildering smörgåsbord of acronyms for various communication protocols. With examples such as I2C, LIN, SPI, TWI, USI, etc., it can get pretty confusing. What do these terms mean? How do you choose the chip that meets your needs? How do you make use of these protocols? This guide will take the mystery out of all these acronyms, and provide a brief overview of what they mean and how you use them in your projects.
Guide to Arduino Communications - [Link]
One of the most powerful tools to have when doing any type of design that involves communication protocols is a protocol analyzer. It allows you to see exactly what the communicating devices are seeing which is very useful for troubleshooting many types of problems that might come up… Wireshark is probably one of the most well-known of all protocol analyzers. [via]
Turning the Freakduino into a Realtime Wireless Protocol Analyzer – [Link]