Water sample collector iot main

IoT Sensor for Water Sample Collector

This IoT sensor module sends a notification over the LoRa network, when the water sample collector is full.

Only, if the water level is high enough during a flood event, it collects water. This IoT solution prevents unnecessary work driving to the collector to check the state manually.

Project Description

The open source solution for the monitoring of water sample collectors features extendability with additional sensors like water level or conductance logging. It enables low-cost, low-entry barrier flexible IoT monitoring without the need of proprietary tools for usage and development.

One advantage is the optimization for battery efficiency. A standby current consumption below 10 µA at an operating voltage around 3.6 V of a single AA-size Tadiran SL-360 Li-SOCl₂ primary cell with 2.4 Ah capacity allows up to 20 years operation on one battery cell.

Goals

• production ready monitoring solution for water samples collectors
• low maintenance
• low cost
• no proprietary tools
• safety oriented design
• small formfactor
• extendability

Current status

• actively maintained

Repository Structure

The structure of this Open Source Hardware repository is based on the OSH-Design-Guideline. It is the root repository for all parts used to build the measurement arm.

The following files are the most important subset needed to build and use the measurement arm:

.
└─┬ src/                                     # git modules/dependencies root
  ├─┬ software/                              # software for the server
  │ └── wsciot/                              # LoRa to email msg. forwarding server
  ├─┬ firmware/                              # runs on the Arduino MKR WAN 1310
  │ ├── check_clock/                         # debugging the RTC
  │ ├── check_connection/                    # debugging LoRa communication
  │ └── keep_alive/                          # the production firmware keep alive msg.
  ├─┬ mech/                                  # 3d printable mounting elements
  │ └── wsciot-mountingframe/                # the blue frame shown in the main photo
  └─┬ elec/                                  # electronic parts/pcbs
    ├── water_sample_collector_iot_main/     # main pcb, 1 piece needed
    └── water_sample_collector_iot_system/   # wiring diagram of the connections of the peripheral components around the water_sample_collector_iot_main

Dependencies

Operation

• The Thing Network: LoRa IoT network service
• Internet device (smartphone, laptop): receive notification

Build

• Arduino IDE: compile and load the firmware
• soldering tools: build the main PCB

Development

• KiCad: change schematics and layout

License

• Software: "AGPL-3.0-or-later"
• Hardware: "CERN-OHL-S-2.0"

Author

Stefan Helmert stefan.helmert@htw-dresden.de Hochschule für Technik und Wirtschaft Dresden -- University of Applied Sciences Friedrich-List-Platz 1 01069 Dresden Germany

Aknowledgement

This work was funded by Volkswagen Foundation under grant number 9C858.

Appendix

Minimal setup wiring

Following components are needed:

• 1 main board
• 1 Arduino MKR WAN 1310
• 1 Li-SOCl₂ battery
• 1 antenna for 868 MHz
• 1 reed switch with cable and activation circuit
• 1 mounting frame

The main LoRa IoT module is fully assembled with battery, antenna, Aduino on the main board and the blue mounting frame:

The back side:

This reed switch must be placed on top of the water sample collector head to be able to register the valve state:

The 6-pin connector of the cable, where the reed switch is attached, must be plugged into the corresponding socket at the main board: