Karaburan

Project Karaburan
Monitoring water quality
Status	Initializing
Contact	bertrik
Last Update	2024-06-24

Next steps

• write python scripts
  • arduino turbidity
  • turbidity-to-mqtt
• hook things into systemd / udev
  • e.g. insert GPS -> create symlink with udev -> trigger (re)start of gpsd

• analoog in op de pi:
  • https://elektronicavoorjou.nl/product/adc-pi/
  • https://www.123materialen.com/products/zeer-nauwkeurige-ads1256-dac8552-ad-da-board-voor-raspberry-pi_1676153
• UPS voor pi: https://elektronicavoorjou.nl/product/raspberry-pi-ups-hat/
• 1-wire stuff:
  • 1-wire adapter emulation on an stm32: https://github.com/alitekin2fx/stm32_ds2480_emu
  • owfs.org for easy interfacing with multiple 1-wire devices in a hierarchical way on linux

investigate RTK GPS

Goal: figure out if it is practically possible to achieve cm resolution with a 200-euro GPS and a free correction service

• https://www.nsgi.nl/referentiepunten-en-gnss-data/gnss-data/real-time-streams public correction data service
• https://www.ardusimple.nl/rtk-in-5-minutes/
• https://www.youtube.com/watch?v=Oc1LBFDj2MA
• Claim: Nauwkeurigheid op centimeterniveau
  • <1cm met een basisstation tot 35km
  • <1cm met NTRIP tot 35km
  • <4 cm met SSR-correcties
  • <1.5 m in stand-alone modus
  • <0.9 m standalone met SBAS-dekking
• Use with Linux / gpsd: https://stackoverflow.com/questions/77314115/drotek-gpsd-and-ntrip-correction-data-for-precise-positioning ?
• Chipsets
  • Quectel LC29H, see https://rtklibexplorer.wordpress.com/2024/04/28/dual-frequency-rtk-for-less-than-60-with-the-quectel-lc29hea/
  • uBLOX ZED-F9P

Edit /etc/default/gpsd, set GPSD_OPTIONS:

 GPSD_OPTIONS="ntrip://user:pass@ntrip.kadaster.nl:2101/CBW100NLD0"

Introduction

Topics:

• air quality sensors
  • ammonia
  • NOx
• water chemical analysis
  • nitrates
  • ammonia
  • dissolved oxygen
  • sulfide/sulfate
  • phosphates?
  • salinity (chlorides?)
• water physical analysis
  • temperature
  • clarity/turbidity -> investigate standard ways of measuring/expressing this
  • conductivity/total dissolved solids
  • water properties by light reflection, hyperspectral/polarity
  • depth?
• boat control
  • trajectory -> steering
  • idea: interface with the remote control, not with the boat
  • idea: find a boat with easily hackable remote control protocol
  • idea: can we get sensor data over this link too, e.g. GPS?
• camera control
• post-processing
  • data presentation
    • video/photo stitching
    • time lapse view
    • map view of properties
• use cases
  • verify with domain experts, how to engage?
  • slootview, under/above water
  • minimum viable prototype
  • high-res measurement by location, by time
• materials
  • boat selection
  • processing platform selection
  • communication platform selection

Air quality sensors

Nitrogen compounds in air

According to https://www.rivm.nl/stikstof/monitoren-advies-onderzoek/overzicht-stikstofmetingen/metingen-stikstof-in-de-lucht average (typical?) values of

• Ammonia (NH3): 6.7 ug/m3 (9.6 ppb)
• NOx: 27.3 ug/m3
• NO2: 18.6 ug/m3 (9.9 ppb)

(ppb-conversion using https://www.breeze-technologies.de/blog/air-pollution-how-to-convert-between-mgm3-%C2%B5gm3-ppm-ppb/ )

RIVM report on inexpensive nitrogen-in-air sensors: https://www.samenmeten.nl/sensoren-voor-no2 Conclusion: most sensors are not sensitive enough to be used in typical outdoor conditions, with perhaps one exception: alphasense NO2-B43F

Water physical analysis

Turbidity / clarity

See https://en.wikipedia.org/wiki/Turbidity

Aliexpress sensor TS-300B: https://nl.aliexpress.com/item/1005006732956937.html Has a range 0 ~ 1000 ± 30 NTU

Order of magnitude for turbidity:

• Drinking water upper limit: 4 NTU (European turbidity standard for drinking water)
• Ambient water: 10-150 NTU. The US state of Washington use a "background" value of 50 NTU as reference.

(see https://en.wikipedia.org/wiki/Turbidity#Standards_and_test_methods )

So the Aliexpress sensor is suited only for "dirty" water.

Boat control

Typically the wireless link looks like this:

• 2.4 GHz working frequency
• 500m range

Interesting links:

• Flytec-2011 remote control https://nl.aliexpress.com/item/1005002984723718.html
• Replacement board for various boats with "18" in their type number: https://nl.aliexpress.com/item/1005006115484716.html
• DIY Multi-protocol module: https://github.com/pascallanger/DIY-Multiprotocol-TX-Module

remote control

Image of remote control RF chip: [...]

Parts:

• 12.000 MHz crystal/oscillator
• 16-pin control chip: 20_CL6L071
• 6-pin RF chip: 1110 / VKA3, could be an rx/tx switch, amplifier or filter circuit

See also: https://www.open-tx.org/

Next steps:

• map out the connections between the mainboard and the rf board, expected: VCC, GND, spi ?

Use cases

material:

• https://www.youtube.com/watch?v=cMk0bGvIU1E
• https://iplo.nl/thema/water/oppervlaktewater/kaderrichtlijn-water
• kaartje: https://krw-nutrend.netlify.app/ -> 2 meetpunten op de reeuwijkse plassen, tijdresolutie is 1 jaar?

Useful distinction, typically used in documents/guidelines:

• chemical quality, what substances are present in the water?
• biological / ecology quality, what kind of living organisms live in the water?

Reeuwijkse plassen

See

• https://www.rijnland.net/wat-doet-rijnland/in-uw-buurt/reeuwijkse-plassen/ their stated goal: CLEAR WATER
• https://www.rijnland.net/regels-op-een-rij/subsidies-en-andere-financi%C3%ABle-bijdragen/

potential applications:

• inspect water sides (oever) over time
• underwater camera: detect invasive cray fish
• sample water properties at high spatial resolution, high time resolution
• early detection of indicators for cyanobacteria: temperature and nutrients

Detect/find pollution source

• ...

Implementation

reading temperature sensor

The idea is to to use a DB18B20 temperature sensor, read it using an arduino nano board acting as a 1-wire adapter. Use openwire-fs as user-side openwire software http://owfs.org

Preparation:

• Add the regular user to the 'dialout' group, so it can access serial ports

 sudo adduser <name> dialout

Setting up the hardware:

• connect the DS18B20 to the connector board with the pull-ups
• wire the connector board to the arduino nano, see ...
• plug the arduino nano in the pi

Setting up the software:

• Install openwire fs

 sudo apt install owfs

• Create the openwire fs mountpoint

 sudo mkdir /mnt/1wire

• Configure owfs, edit /etc/owfs.conf

 server: device = /dev/ttyUSB0
 mountpoint = /mnt/1wire
 allow_other
 (comment out the line with the FAKE devices)

• Configure systemd services

 sudo systemctl enable owserver owhttpd
 sudo systemctl disable owftpd

• Start the systemd service

 sudo systemctl start owserver owhttpd

• Check the logs

 sudo journalctl -xeu owserver -f

• Open a browser to view the web interface

 http://localhost:2121 or
 http://raspberrypi.local:2121