Whisper Node - AVR

A real ultra-low power LoRa development board based on the popular Atmel AVR ATMega328p - Arduino compatible. 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 a USB charger, and take advantage of the ultra-low quiescent current MCP1700 LDO regulator, capable of 250mA, providing more flexibility while developing or running hunger projects. The board also counts with a smart voltage monitor, which will automatically switch from a power supply to the battery in case of power-loss or vice-versa. Alternatively, you could use a Li-Po cell, and the board will decide to use the LDO or the Step-up regulator based on the cell voltage to maximise the running time on a single charge.

As standard, this board comes with an RFM69HW Sub-GHz RF module (Semtech SX1231H), giving you wireless connectivity out of the box! The RFM69 is a very popular FSK/OOK radio, proven to offer excellent cost/benefit for any project requiring RF communication at low-power.

Finally, a W25X40CL 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 around 6µA in sleep mode when powered by a 3V source, like two Alkaline cells.

The Whisper Node board ships with all headers (un-soldered) and external 1.5dBi (± 0.7 dBi) PCB antenna with a u.FL connector, matching the radio frequency. The small PCB antenna provides an excellent balance between performance and size.

Moreover, the board can be easily upgraded to fit an SMA antenna connector, a temperature compensated real-time clock, a CR2032 battery holder or a high-capacity LDO, making the board an ideal as a low-power remote node or as a sturdy base station.

Documentation
https://bitbucket.org/talk2/whisper-node-avr