Sentrifarm - open hardware telemetry system for Australian farming conditions - Andrew McDonnell - LCA2016

Andrew McDonnell created Sentrifarm in 2015.

Requirements

• Low power
• Distributed
• Using radio for communication
• Local storage
• Cheap

Background

• They entered Hackaday - actual entry page.
  • Wanted to learn new skills
  • Have fun
  • Experiment
  • Perhaps produce something useful
• There were lots of discarded prototypes
• So many cheap devices facilitating experimentation.
• Radio links were not quite as open as he would have liked.
• Used Lora based ISM-band radio
• Learned how much easier it is to have PCBs fabricated these days.
• Fabrication lead times can be about 6 months.

Open Hardware Components

• 8 devices Carambola2 - Linux OpenWRT board

Firmware

• platform.io
• Replaces need for Arduino IDE
• Open Source
• IDE agnostic

MQTT for communication

• Specifically MQTT-SN for low bandwidth
• Packages
  • mosquitto
  • mqtt_sn_tools
  • arduino-mqtt-sn
• Gateway runs OpenWRT

Andrew provided an overview of how the gateway processing model worked.

Backend

• Ubuntu 14.04
• Docker 1.8.3
• Carbon + Whisper + Graphite
• Grafana
• Custom Python scripts

• Millions of lines of code and Andrew only had to write 7.

• 3D printed some components.

  • Made a custom holder for the PCB
• Used OpenSCAD to design the component.
• Made the antenna himself with plans off the Internet.
  • Got range up to 9km.

Andrew's project is an ingenious solution to a serious problem. I need one of these for myself!

Updated:

Added the talk itself below.