The Texas Instruments MSP430 family of ultralow-power microcontrollers consists of several devices featuring different sets of peripherals targeted for various applications. The architecture, combined with five low-power modes, is optimized to achieve extended battery life in portable measurement applications. The device features a powerful 16-bit RISC CPU, 16-bit registers, and constant generators that contribute to maximum code efficiency. The digitally controlled oscillator (DCO) allows wake-up from low-power modes to active mode in less than 1 s. The MSP430G2x21/31 series is an ultralow-power mixed signal microcontroller with a built-in 16-bit timer and ten I/O pins. The MSP430G2x31 family members have a 10-bit A/D converter and built-in communication capability using synchronous protocols (SPI or I2C). For configuration details, see Table 1. Typical applications include low-cost sensor systems that capture analog signals, convert them to digital values, and then process the data for display or for transmission to a host system.