STM32 DHT11 Integration Sensor Data Acquisition & Processing

Project Description

This project demonstrates how to interface a DHT11 temperature and humidity sensor with an STM32 microcontroller using the GPIO bit-banging protocol. The project also includes real-time data display via UART and full Proteus simulation support.

The DHT11 is a low-cost digital sensor that measures both temperature and humidity. It communicates using a single-wire protocol, making it simple to interface with microcontrollers. Although it has limited precision compared to advanced sensors, its affordability and ease of use make it a popular choice for learning and basic IoT applications.

STM32CubeMX Setup

• MCU Selection: STM32F103C6 (16 MHz clock)
• GPIO Configuration:

-PA0 as Open-Drain Output (DATA line)

• TIM1 Configuration:

• -Prescaler = 15,
• -Counter Period = 65535 (for µs delays)

• UART1 Configuration:

• -115200 baud
• -8-bit data
• -no parity

• Generate initialization code and open the project in STM32CubeIDE.

STM32CubeIDE Implementation

Key Functions:

• void DHT11_Init(); → Configures GPIO and timer
• void DHT11_Read(float *temp, float *humidity); → Reads sensor values
• printf("Temp: %.1f°C, Humidity: %.1f%%\r\n", temp, humidity); → UART output

Proteus Simulation

Components:

• STM32F103C6
• DHT11 Sensor
• Virtual Terminal

Connections:

• DATA pin → PA0
• UART1-TX → Virtual Terminal

Simulation:

• Load the generated.hex file
• Observe temperature and humidity values in the terminal

That's all!

If you have any questions or suggestions don't hesitate to leave a comment below