Bus Pirate v4is a universal bus interface that talks to electronics from a computer serial terminal. Get to know a chip without writing code. Eliminates a ton of early prototyping effort with new or unknown chips. Seeed Studio is the official manufacturer and supporter of the Bus Pirate project. Version 4 is the next generation Bus Pirate hardware, but it's not as stable asBus Pirate v3. If you're just starting out with the Bus Pirate we still recommend v3 - it's cheaper, more reliable, and has all the same major features. See aBus Pirate v4 vs v3 comparison.Protocols1-Wire, I2C, SPI, JTAG, asynchronous serial (UART), MIDI, PC keyboard, HD44780 LCDs, and generic 2- and 3-wire libraries for custom protocols.