06 June 2015

The Double-A XBee Sensor Node

This is my design for an Arduino-compatible (ATmega328P), low-power sensor node using an XBee ZB module. This node can operate as part of the GroveStreams Wireless Sensor Network that I described in my previous post. I call it the Double-A XBee Sensor Node since it runs on a pair of AA cells.

Although I haven't done a lot of testing, I believe it should run for over a year on a pair of AA alkaline cells. This will be affected by the power requirements of additional sensors, supply voltage (either 3.3V or 5V can be selected) and data transmission frequency. The basic board with no additional sensors draws less than 5µA while sleeping.

The AA XBee Node includes an accurate real-time clock (DS3231, ±2ppm from 0°C to +40°C) for precise timing of data transmissions and an accurate on-board I2C temperature sensor (MCP9808, ±0.25°C typical). A prototyping area is provided for connecting additional sensors. Twelve microcontroller GPIO pins are available to interface with sensors, including the I2C and SPI buses and analog inputs. A pushbutton switch and an LED are available for application use if needed.

For more information

The Double-A XBee Sensor Node is an open-source project. For complete information on the circuit design, including Eagle files, configuration options, programming requirements, etc. see the GitHub repository.

For an example sketch, see the aaXBee sketch which is part of my GroveStreams library. Using this sketch, the AA XBee Node sends data to an Arduino running the gsGateway sketch, which forwards it to the GroveStreams web site.

3 comments:

  1. Excellent. I like the low power nature of your projectself. Do you have any estimates on how long will the AA batteries would last with your software routines? And did you create the board with eagle?
    Thanks for publishing

    ReplyDelete
  2. Excellent. I like the low power nature of your projectself. Do you have any estimates on how long will the AA batteries would last with your software routines? And did you create the board with eagle?
    Thanks for publishing

    ReplyDelete
    Replies
    1. Hi, glad you like the project. I've had one running now for almost 14 months, sending data once per minute. YMMV depending on how long the wake time is to read sensors, etc. The board was done in Eagle.

      Delete