Project work - pfusch.zone

Project work

Development and implementation of a system for acquisition and processing of sensor data.

Development and implementation of a system for acquisition and processing of sensor data.
As project work during my further education as a mechatronics technician, I did the following IoT project:

Project

Project description

Goals

  • Get an overview of a complex central heating system
  • Control processes
  • Optimize the existing control
    schema heating system
    System diagram of the present heating system with planned measuring points

Requirements

  • Equip the heating system with sensors
  • Collect sensor data
  • Present sensor data on a website
  • Run data-based actions

image One section of the resulting website displaying collected sensor data

Course of action

Concept

The idea was to develop a custom system, instead of using proprietary components like a PLC or industrial sensors.
This would result in a scalable and cost-efficient solution using common consumer electronics. concept of the planned system
Concept schema of the developed system

Tasks

  • Developing a custom PCB
  • Choosing components
  • Designing parts
  • Manufacturing assemblies
  • Developing software
  • Testing and evaluating
  • Documenting the project in a technical report

image Layout of the designed PCB in KiCad

Conclusion

Implemented Features

  • Multi-purpose PCB:
    • Read various sensors
    • Control things with relay and MOSFET outputs
    • WiFi Capability
  • Send sensor data to central server
  • Store data in a database
  • Access data via a web interface
  • Analyze data, send notifications
  • Send commands from server to PCB

image One of the PCBs wired and mounted on a wall next to the heating system

Projects based on this one

In this particular project a central heating system is monitored and controlled using the developed pcb.
However, the multi-purpose PCB was planned to be used in various other, future projects.

image Developed PCB used for controlling the Electric Armchair V2


Components

Hardware

Custom PCB

  • 100x100 mm 2-layer PCB
  • ESP32 microcontroller
  • 2x TPS562200 Voltage regulator
  • 6x Si2302 N-Channel MOSFET
  • 2x IRF7455 N-Channel MOSFET
  • LEG-12 Relay
  • Buzzer, SMD LED
  • Screw terminals
  • Various passive components

image SMT components

Sensors

  • 25x DS18B20 temperature sensor
  • 1x PT100 temperature sensor
  • 3x Pressure sensor
  • 4x Current sensor
  • 1x SHT10 temperature, humidity sensor (outdoor)
  • 3x SHT33 temperature, humidity sensor

Mechanical

  • 3d-printed housing
  • Custom brass adapters for pressure sensors
  • Custom aluminium holders for temperature sensors

image Pressure sensors with custom brass adapters

Software

Programming

  • ESP-IDF Espressif IoT Development Framework (C)
  • Node-Red (JavaScript)
  • MySQL (SQL)

Protocols

  • MQTT

Tools

  • KiCad
  • Inkscape
  • LaTeX
  • draw.io

ESP-IDF toolchain
ESP toolchain (source: espressif.com)

image Logos of software used in this project

Gallery