Nrf51822 is one for ultra-low power wireless applications (ulp wirelesss applications) to create a multi-protocol single-chip solution. It integrates the leading nordic wireless transmitter supports bluetooth (r) low energy and a dedicated 2. 4ghz protocol stack. The basic situation is: 2. 4ghz multi-protocol radio frequency 32-bit arm cortex m0 processor 128-bit aes hardware encryption processor 256kb flash/32kb ram programmable peripheral interface ppi full-featured digital interface: Spi/i2c/uart 10 aDC programmable output power: + 4dbm to -20dbm.