Whisper Node: an ultra-low power Arduino board with built-in RF (RFM69)

What's Whisper Node?
It's a real ultra-low power board based on the popular Atmel AVR ATMega328p, an Arduino Clone. Thanks to the highly efficient MCP16251 Step-up Switching regulator, this board can be powered with little as 0.9V. In other words, you can run it on a single Alkaline Cell until the battery is totally dry.

Alternatively you could connect a 5V power supply, like an USB charger, and take advantage of the dual 300mA LDO regulator, giving more flexibility while developing or running hunger projects. Having two independent 3.3V rails is a great solution to prevent other components from taking power of the core circuits.

As standard, this board comes with a RFM69W Sub-GHz RF module, giving you wireless connectivity out of the box! Finally a W25C40 4MBit SPI Flash is attached to the PCB, giving you plenty of storage and option for remote firmware upgrade over-the-air. You get all this running on a board that consumes less than 4µA in sleep mode when powered by a 3V source, like two Alkaline cells.

Dimensions and Connections

  • Board size: 65.65 x 26.75 x 1.6mm + connectors overhanging
  • GPIOs: Two 17 Pin PCB Header to access all MCU Pins, Vin, Vbat, and both 3.3V Rails
  • Standard 3×2 ISP Header
  • 6 Pin FTDI Header
  • Micro USB for External Power supply
  • Pico-blade 1.25mm for Battery Connection
  • RF SMA Connection for external Antenna


  • MCU Atmel 8-bit AVR: ATMega328P-AU (32Kb WhisperNode_0.3v_RTC_CR2032Flash/2Kb RAM)
  • 4Mbit SPI Flash: W25X40
  • Sub-GHz RF Module: RFM69
  • Step Up Switching Regulator: MCP16251
  • Dual LDO Regulator: AP7332
  • 16Mhz high precision Crystal
  • 2x Feedback LEDs (Blue and Yellow)
  • 2x Tactile User Buttons
  • 2dB omni-directional SMA antenna


  • CR2032 Battery Holder
  • Real-Time Clock Kit
  • High Input Voltage LDO 1117 Kit

Additional Resources

Where to Buy
Available on our official on-line store: Whisper Node - AVR - Wisen