Smart fan
A smart fan with a built-in display.
Author: Herghelegiu Rares-Andrei
GitHub Project Link: https://github.com/UPB-PMRust-Students/project-RaresAndrei0
Description
A smart fan that features an integrated digital display for real-time temperature monitoring. It automatically activates when ambient temperature exceeds a user-defined threshold.
Motivation
I chose this project because it presented a manageable challenge for someone with my current level of programming experience. Additionally, given the ongoing concerns around global warming and the need for more energy-conscious solutions, developing a fan that operates autonomously based on temperature thresholds seemed both practical and timely. It aligns well with sustainability goals while allowing me to grow my technical skills through a meaningful application.
Architecture
Raspberry Pi Pico 2W
Acts as the main controller of the project — reads temperature from the sensor, controls the fan via the L293D motor driver, and updates the LCD display with temperature data and fan status.
DHT22 Temperature Sensor
Single-wire digital interface. Measures temperature and humidity, used to determine whether the fan should turn on or off.
LCD 16x2 Display (I2C module)
Displays real-time temperature readings and fan status (“ON” / “OFF”).
L293D Motor Driver
Using the GPIO, controls the 5V fan by switching it on/off based on temperature thresholds received from the Pico.
5V Fan
Controlled via L293D outputs, activates automatically when temperature exceeds a certain threshold.
Log
Week 28 April - 4 May
After submitting the project proposal and refining it to add complexity, as advised by the lab professor, I proceeded to purchase the necessary components and began assembling the system. I encountered my first major issue when attempting to interface the DHT-22 temperature sensor with the Raspberry Pi Pico. Although I identified an embassy-rs crate that supports the sensor, it turned out to be non-functional. Unfortunately, the DHT-22 lacks broader support outside of this crate, leaving me with two options: either switch from Embassy to another framework, such as Tock, or attempt to fix the existing crate by rewriting or adapting a significant portion of its rather complicated codebase.
Week 5 - 11 May
Week 12 - 18 May
Week 19 - 25 May
Hardware
Detail in a few words the hardware used.
Schematics
Place your KiCAD schematics here.
Bill of Materials
| Device | Usage | Price |
|---|---|---|
| Raspberry Pi Pico W | The microcontroller | 35 RON |
Software
| Library | Description | Usage |
|---|---|---|
| st7789 | Display driver for ST7789 | Used for the display for the Pico Explorer Base |
| embedded-graphics | 2D graphics library | Used for drawing to the display |