This chapter presents a complete realistic microcontroller project written entirely in Assembly Language. A Pico-series device collects data and then provides it to a central server. Since this is a book on Assembly Language and not electronics, components built into the Pico-series are used, rather than requiring extra components. The built-in temperature sensor is used to collect data, and then the program communicates with a server using UART1. It’s used rather than UART0, so that UART0 can be used for debugging and receive output from printf statements. The assumption is that a Raspberry Pi is used for debugging and development, so this is used as the server and a Python program is written to poll the various devices connected to it for data.