Features:

• 32-bit ARM® Cortex™-M0

• 2MB QSPI flash, 1MB of which is available for   persistent application data

• Dialog Semiconductor DA14681-01, Cortex-M0 at   up to 96MHz, with hardware encryption engine.

• Input/output    Two I2C interfaces (master/slave, 100 & 400kHz)    
  SPI master (MOSI, MISO, SCLK), Two UARTs    
  Up to 15 GPIOs, 6 ADC channels and 4 PWM   depending on configuration

• Power supply    
  1.7V to 4.75V    
  6.5uA in sleep (32kHz clock active)    
  70uJ per advertisement