Bluetooth v5.1 wireless MCU with 128 kB Flash
The Texas Instruments CC2640F128RSMT is a SimpleLink wireless microcontroller integrating a Bluetooth v5.1-compliant radio with an ARM Cortex-M3 core. It carries 128 kB of Flash and 28 kB of SRAM, enough for a BLE application profile plus an OTA update staging buffer. The receiver hits -97 dBm sensitivity, and the transmitter delivers up to 5 dBm output power — a combination that gives a clean link budget for battery-powered sensors and beacons operating in the 2.4 GHz band.
Supply range and current draw — battery design fit
The supply range spans 1.8 V to 3.8 V, so a single CR2032 coin cell or a Li-Po can power it without a boost regulator. Receive current sits between 5.9 mA and 6.1 mA; transmit current runs 6.1 mA to 9.1 mA depending on output power setting. Those numbers are typical for a BLE SoC in this class and leave headroom for the sensor and interface loads on the same rail.
10 GPIOs and serial interface set
Ten GPIOs are available, multiplexed with I2C, I2S, JTAG, SPI, and UART interfaces. That is enough for a typical BLE sensor node — one I2C for an IMU or environmental sensor, one UART for a debug or host link, and a few remaining pins for button, LED, and interrupt lines.