House Mill Sonar Box

Project with volunteers at House Mill to monitor flood waters in a grade 1 listed building.

Using Maxbotix MB7389 (5m range) - https://maxbotix.com/pages/hrxl-maxsonar-wr-datasheet

Also using tide information from https://pla.co.uk/Safety/Tidal-information

Website

A Grafana dashboard of data captured is available.

Sensor Box Scripts

Sensor Box at House Mill 51.527220, -0.007761

sonarbox-scripts/sonar-camera.py

Script to take time lapse photos every 2 mins when water is above floor - script defaults to 1000mm

sonarbox-scripts/sonar-median-mqtt.py

Takes median of 11 readings coming in from Serial (Arduino sketch) and then posts to mqtt broker. Runs every 10 minutes.

Other scripts (running on RPi in office)

Note: Requires:

pip install beautifulsoup4
pip install pytz
pip install selenium
pip install paho-mqtt

Also had to install chromedriver to use selenium

sudo apt-get install chromium-chromedriver

server-scripts/river-level.py

Webscrapes river level info from https://riverlevels.uk/ and posts them to mqtt broker every 15 mins.

Lea Bridge Coordinates: 51°34'4"N 0°3'3"W (51.567832,-0.051025)

Silvertown Tidal Coordinates: 51°29'51"N 0°3'9"E (51.497504,0.052616)

Tower Pier Tidal Coordinates: 51°30'24"N 0°4'43"W (51.506753,-0.078706)

https://riverlevels.uk/levels/greater-london

server-scripts/pla.py

Webscrapes tide / river level info from http://www.pla.co.uk/ and posts them to mqtt broker every 15 mins.

Charlton 51.496765, 0.034353

Silvertown 51.498080, 0.039556

Tilbury 51.449332, 0.349288

Tower 51.505296, -0.075174

sonarbox-scripts/config.py (.gitignored)

Passwords file containing following information: mqttusername="xxx" mqttpassword="xxx"

Arduino Sketches

arduino-sketches/maxbotix7389read

Basic sketch to read from sensor using pin 3

arduino-sketches/maxbotix7389read_7seg

Basic sketch to read from sensor and display on 7 segment display

arduino-sketches/maxbotix7389read_TTL

Basic sketch to read from sensor using pin 5

Crontab settings

On sensor box:

1-59/2 * * * * /usr/bin/python3 /home/pi/Desktop/sonar-camera.py
*/10 * * * * /usr/bin/python3 /home/pi/Desktop/sonar-median-mqtt.py  >> /home/pi/Desktop/sonar.log 2>&1

on office RPi:

1,16,31,46 * * * * /usr/bin/python3 /home/pi/Desktop/river-level.py >> /home/pi/Desktop/river.log 2>&1
1,16,31,46 * * * * /usr/bin/python3 /home/pi/Desktop/pla.py >> /home/pi/Desktop/pla.log 2>&1

Wiring

Arduino Uno:

• Maxbotix: 5V, GND + Maxbotix pin 3 to Arduino A0
• 7seg: 3.3V, GND + SDA, SCL (SDA on 7seg is end pin opposite corner to 3.3V and pin A4 on Arduino Uno) (SCL on 7seg is second pin opposite corner to 3.3V and pin A5 on Arduino Uno)

RPi:

• RPi cam v2.1 NOIR used
• Initially used https://cpc.farnell.com/cyntech/lisiparoiir-01/rpi-ir-board-for-pi-camera/dp/SC13919 which was controlled via GPIO4 on pi - but LED's not bright enough so used separate source.

Sensor Locations

Note: added as JSON file also.

Sensor Box at House Mill, UCL, 51.527220, -0.007761

Charlton, PLA, 51.496765, 0.034353

Silvertown, PLA, 51.498080, 0.039556

Tilbury, PLA, 51.449332, 0.349288

Tower, PLA, 51.505296, -0.075174

Lea Bridge, River Levels, 51.567832,-0.051025

Silvertown Tidal, River Levels,51.497504,0.052616

Tower Pier Tidal, River Levels,51.506753,-0.078706