Sensor Networks with Java on Embedded

Discover how to create a reliable and low-power sensor network for home use using Arduino, Raspberry Pi, and XP sensors with Java, MQTT, and MongoDB, all in a DIY-friendly talk.

Key takeaways
  • Gerhard Goenwald, Java technology evangelist at Oracle, presented a conference talk on “Sensor Networks with Java on Embedded” where he discussed creating a sensor network for home usage using Arduino, Raspberry Pi, and XP sensors.
  • He created a sensor network for nine rooms in his house, measuring temperature, humidity, and pressure, with the goal of creating a reliable and low-power network.
  • The setup uses MQTT for publish-subscribe, and Java FX on the Raspberry Pi for visualization.
  • It was challenging to get MongoDB running on the QB board, but he was able to use it as a database using an ARM port.
  • He optimized the network by reducing the power consumption to around 45-90 milliamps, which allows it to run for weeks on batteries.
  • The sensors (XP series) are cheap, around 20-35 euros each, and have analog and digital inputs.
  • He demonstrated how to measure temperature, humidity, and pressure, and store data using MQTT and MongoDB.
  • Java 8 was used on the Raspberry Pi for publishing sensor data.
  • The talk highlighted the importance of mesh networking for reliable data transmission, and the use of XP sensors for broadcasting messages in the network.
  • He concluded that the XP sensor network is a perfect fit for small-scale home usage or small companies, and that Java is a suitable language for most tasks in this setup.