Introduction: NRF52840 is a ProMicro alternative development board that is compatible with for Nice! Nano. Its pins are the same as ProMicro, which means it can be used with for almost any ProMicro keyboard. The NRF5280 development board has a 3.7V lithium battery interface and a software switch that can cut off the power of the LED. When turned off, the standby power consumption can reach 1mA. nRF52840 is a high-performance, low-power wireless SoC chip launched. It supports multiple wireless protocols, including Bluetooth 5, Thread, Zigbee, ANT, and 2.4GHz. The nRF52840 chip uses an ARM -M4F processor, clocked at 64MHz, with built-in 1MB of flash memory and 256KB of RAM. It also has a of peripherals, including ADC, PWM, SPI, I2C, UART, USB and GPIO, etc. In addition, nRF52840 also supports a of security functions, such as encryption, SHA-256 hashing and True Random Number Generator (TRNG). Product Parameters: Powerful wireless capabilities: Bluetooth 5.0 onboard antennaPowerful CPU: nRF52840 chip uses ARM -M4F processor, clocked at 64MHz, built-in 1MB flash memory and 256KB RAM Battery charging chip: supports lithium battery charging and discharging Power consumption: standby power consumption can reach 1mA for Promicro NRF52840 Material: PC,Metal colour: Black Package Contents: 1 x NRF52840 Development Board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.