The R5F2M121ANSPU0 is a microcontroller from Renesas, part of their RX family. This 8-bit microcontroller has a maximum operating frequency of 24 MHz and 64KB of on-chip flash memory. The device also features analog and digital peripheral functions, such as an 8-channel A/D converter, an 8-bit timer/counter, an 8-bit D/A converter, and an LCD controller. Other features include a low-power supply voltage range of 2.7-3.6V, a voltage detection circuit, a watchdog timer, and other I/O pins.