Wednesday 25 January 2017


Rule-Based Fault Management for Environmental Monitoring IoT system

Hardware setup

For the hardware part of the system I'm using two DIY environmental sensors where each sensor consists of two parts: the external part, mounted on the outside of the window and the internal part, mounted in the apartment of the apartment building.

The internal part

The internal part is a ESP8266 module powered with LiPo 3.7V 700mAh battery. After submitting the proposal I started to work on its hardware components. And my initial development configuration looked like this:

But since my project won the Gift Certificate I've decided to apply it and after a little waiting got this goodies from SparkFun:

and modified the prototyping setup:

This is a final configuration that I used to develop the sensor driver software. I'll describe the sensor software development in the next post.

SparkFun ESP8266 Thing has onboard voltage regulator and charger for 3.7V LiPo batteries. It is a great addition for solutions with autonomous power supply.

The components are mounted on a small solderable breadboard with 2x10-pin stackable headers and 4-pin break away header for the sensor ribbon cable on it:

Assembled boards and LiPo batteries are placed in a protective enclosure which made of latticed PVC-plates. The enclosure has a separate section for each board.The back panel is removed to provide access to the ESP8266 Thing power switch and Micro USB connector.

The external part

For the external part I made two simple sensor holders. The holder allows to place the BME280 sensor at a distance from the wall of the building to slightly reduce the impact of the wall proximity on the temperature measurement. Also it provides partial protection from the weather conditions.

Simple raw materials:

And it has not done without hot glue :)



Unfortunately I burned one SparkFun BME280 sensor breakout board, so I had to go with 4-pin BME280, which I bought on eBay earlier last year. Here is bottom-up view of covers with sensors inside:
I attached sensor holders to the window and put the fully assembled device on a sill:

Done.

Btw, it's true: there is a lot of snow in winter in Russia :)