The new radio microcontroller module XIAO ESP32C3 from Seeed Studio is only the size of a thumbnail (21 x 17.5mm2) and features the current 32-bit processor core in RISC-V architecture from Espressif, which can be clocked at up to 160MHz thanks to the four-stage pipeline . The module offers 11 GPIOs (partly with PWM) at interfaces, which can also be configured as UART, I2C, I2S, SPI or ADC (4 channels).
The HF front end supports WiFi/Bluetooth connections over 100m, but also Bluetooth 5 and Bluetooth mesh in low-power mode. 400KByte SRAM and 4MByte flash memory are available for your own programs.
The manufacturer emphasizes the low stand-by power consumption of only 44µA and the built-in charging electronics for LiIon cells. The circuit board contains practical buttons for reset and programming via bootloader as well as a socket for the external antenna. The module will cost $4.99 if you pre-order it and will be in stock by mid-August.