Development and implementation of a system for acquisition and processing of sensor data.
As project work, during my further education as technician in mechatronics, I decided to do the following IoT-Project:
Project
Project description
Goals
- Get an overview of a complex central heating system
- Control processes
- Optimize the existing control
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
One section of the resulted website displaying collected sensor data
Course of action
Concept
The idea was to develop an own 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 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 scientific paper
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
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.
Developed pcb used for controlling the electric armchair v2
Components
Hardware
Custom pcb
- 100x100 mm 2-layer pcb
- ESP-32 microcontroller
- 2x TPS562200 Voltage regulator
- 6x Si2302 N-Channel Mosfet
- 2x IRF7455 N-Channel Mosfet
- LEG-12 Relay
- Buzzer, smt led
- Screw terminals
- Various passive components
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
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 toolchain (source: espressif.com)
Logos of software used in this project