The nRF52832 BLE Node based on nRF52832, integrates GPIO, PWM, IIC, analog inputs, PWM, timers, etc all in one board. Leaving out the extra microcontroller means the price, complexity, and power-usage are all lower/better. It allows you to run code directly on the nRF52832, straight from the Arduino IDE as you would with any other MCU or Arduino compatible device.
It is a built-in USB and battery charging.
Working voltage: 3.7V Lipo battery or USB Connector
ARM Cortex M4F running at 64MHz
512KB flash and 64KB SRAM
Built-in USB Serial converter
Bluetooth Low Energy compatible 2.4GHz radio
FCC / IC / TELEC certified module
Up to +4dBm output power
19 GPIO, 8 x 12-bit ADC pins, up to 12 PWM outputs