20-TSSOP footprint and board integration
The MSP430G2132IPW20R: The 0.65 mm pitch is routable on a 2-layer board with 6/6 mil trace/space rules — no micro-vias needed. The exposed die pad is not present; thermal dissipation relies on the leadframe and board copper. Decouple Vcc with a 100 nF ceramic within 5 mm of pin 1 (Vcc) and pin 20 (GND).
16 MHz CPU16 core and memory budget
The MSP430 CPU16 core runs at 16 MHz, delivering about 16 MIPS — enough for sensor polling, simple PID loops, or serial protocol handling. The 1 KB Flash (1 K × 8) holds roughly 500–800 instructions after the interrupt vector table and stack; the 128 B RAM (128 × 8) leaves about 80 B for variables after the register save area. Firmware must fit within this budget — a bootloader or OTA update is not practical without external memory. The USI module supports I²C and SPI in master or slave mode without a separate serial engine.
Brown-out detect and POR are integrated, so no external reset supervisor is needed. The 8-channel 10-bit ADC samples at up to 200 ksps — adequate for reading temperature sensors, potentiometers, or current-shunt voltages at low update rates. Each analog input is muxed to the ADC core; an external reference can be applied for ratiometric measurements.