For light relief from hacking, I looked over the eval board David gave me, and decided to see what was better about it, compared to the nRF51822.  I see four significant advantages.


  1. Power consumption is about 5x (sic) better
  2. Double the memory.
  3. It looks like it might be possible to have multiple SPI channels active, so avoiding multiplexing.
  4. BLE TX/RX use 60% power, or better.

Key features

2.4 GHz transceiver

  • -96 dBm sensitivity in Bluetooth® low energy mode (3dBm better)
  • 1 Mbps, 2 Mbps supported data rates
  • TX Power -20 to +4 dBm in 4 dB steps
  • Single pin antenna interface
  • 5.5 mA peak current in RX and TX (0 dBm)  (was 9.7 Rx/8 Tx)
  • RSSI (1 dB resolution)

ARM® Cortex™-M4 32-bit processor with FPU, 64 MHz

  • 52 μA/MHz running from flash memory (was 275 μA/MHz running from flash memory)
  • 48 μA/MHz running from RAM (150 μA/MHz running from RAM)
  • Data Watchpoint and Trace (DWT), Embedded Trace Macrocell (ETM), and Instrumentation Trace Macro cell (ITM)
  • Serial Wire Debug (SWD)
  • Trace port

Flexible Power Management

  • Supply voltage range 1.7 V to 3.6 V – (was 1.8 V to 3.6 V)
  • Fully automatic LDO and DC/DC regulator system
  • Fast wake-up using 64 MHz internal oscillator
  • 0.4 μA at 3 V in OFF mode (was 0.6)
  • 0.7μA at 3 V in OFF mode with 32 kB RAM retention (was 1.2uA)
  • 1.9 μA at 3 V in ON mode, 32.768 kHz crystal oscillator and Real Time Counter running with 32 kB RAM retention


  • 512 kB flash/64 kB RAM  (256 kB  flash /32 kB RAM)

Nordic SoftDevice ready
Support for concurrent multi-protocol
Type 2 Near Field Communication (NFC-A) Tag with wakeup on field
12-bit, 200 ksps ADC – 8 configurable channels with programmable gain
64 level comparator
15 level low power comparator with wakeup
Temperature sensor
32 General Purpose I/O Pins
3 x 4 channel Pulse Width Modulator units with EasyDMA
Digital microphone interface (PDM)
5x 32-bit timers with counter mode
Up to 3x SPI Master/Slave with EasyDMA
2x I2C compatible 2-Wire Master/Slave
Programmable Peripheral Interconnect (PPI)
Quadrature Decoder (QDEC)
AES HW encryption with EasyDMA
3x Real Timer Counter (RTC)
Package variants
QFN48 package, 6 x 6 mm
WLCSP package, 3.0 x 3.2 mm

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