Karaburan

Project Karaburan
Monitoring water quality
Status	Initializing
Contact	bertrik
Last Update	2024-07-07

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

USB HID as analog input

An stm32 based bluepill board can be flashed with firmware to allow its analog input to be exposed as USB HID sliders.

How to flash the stm32:

• install openocd
• connect an stm32 bluepill to an stlinkv2
• flash the freejoy firmware as follows
  • download the firmware from XXX
  • create a symlink to the hex file called firmware.hex
  • flash the initial firmware from the command line

 openocd -s /usr/share/openocd/scripts -f interface/stlink.cfg -f target/stm32f1x.cfg -c init -c "program firmware.hex verify reset exit"

• connect the stm32 using a USB cable
• download the freejoy configurator from https://github.com/FreeJoy-Team/FreeJoyConfiguratorQt
• start and load the karaburan.cfg setting

See also https://github.com/vostrenkov/EazyJoy

influxdb

See https://hub.docker.com/_/influxdb

See https://github.com/bertrik/karaburan/tree/master/influxdb

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: YES

• 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/
• RTK in action https://www.youtube.com/watch?v=Oc1LBFDj2MA
• 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
• Boards
  • UM980 / UM982

Edit /etc/default/gpsd, set GPSD_OPTIONS:

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

Option -G exposes the control socket on all network interfaces, option -n keeps the GPS active if there is no one currently connected.

Plotting live location on a map:

• Configure gpsd to expose its socket to the outside world: last section of https://gpsd.gitlab.io/gpsd/troubleshooting.html
• In QGIS, press ctrl+0 to show the GPS information tab, enter the name of the remote gpsd (port 2947)

Station at Stolwijk (close to Gouda): https://gnss1.tudelft.nl/dpga/station/Stolwijk.html#STWK ?

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