A UART is a Universal asynchronous receiver/transmitter
. The most well-known implementation is for serial ports on PCs, where the 16550
is (or was, anyway) ubiquitous. It is an IC. A USART is similar, except that it also provides synchronous serial capability. Whether you could get one to work with an Arduino would depend, I guess, on the which chip you were trying to use, and how much work you wanted to put into programming. Since the Arduino already has TX/RX pins, and there are many existing solutions for serial communication, I don't think I'd be looking around generically for UARTS. I admit that I don't know, for example, whether the Maxim 3322E
fits the definition of a UART (I suspect it does), but there's already information on using it
. Or search the forum for RS485. I'm sure there are many options for serial communications, but it depends a lot on what you're trying to do.
SPI is SoyuzPlodImport
, a Russian company known for being the producer of Stolichnaya vodka. I prefer Ketel One myself, but Stoli is pretty good stuff too.
Or, it could be the Serial Peripheral Interface Bus
, which defines an electrical and communications standard for serial communication among devices. There is a SPI library for Arduino
There's a handy search box at the top of every page. It will find lots and lots of info for you.