[2022 Digi-Key Innovation Design Competition] Distributed Temperature and Humidity Acquisition System - Brief Design Overview

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[2022 Digi-Key Innovation Design Competition] Distributed Temperature and Humidity Acquisition System - Brief Design Overview [Copy link]

 

A system design block diagram

As the main control system, the STM32H745I-DISCO development board is responsible for the acquisition and storage of temperature and humidity data. The main control board needs to collect temperature and humidity data scattered at various points and connect to the wireless router through a network cable. The wireless router serves as a data bridge between the main control board and each sampling point.

2. WIFI module

By collecting information from the Internet, I learned about Lianshengde's WIFI chip W800 development board. Through the development board, I added the functions of buzzer, LED, temperature and humidity sensor.

The W800 chip is a secure IoT Wi-Fi/Bluetooth dual-mode SoC chip. It supports 2.4G IEEE802.11b/g/n Wi-Fi communication protocol; supports BT/BLE dual-mode working mode, and supports BT/BLE4.2 protocol. The chip integrates a 32-bit CPU processor, built-in UART, GPIO, SPI, SDIO, I2C, I2S, 7816, ADC, TouchSensor and other digital interfaces; supports TEE security engine, supports multiple hardware encryption and decryption algorithms, built-in DSP, floating-point unit and security engine, supports code security permission settings, built-in 2MBFlash memory, supports firmware encryption storage, firmware signing, secure debugging, secure upgrades and other security measures to ensure product safety features. It is suitable for a wide range of IoT fields such as smart home appliances, smart homes, smart toys, wireless audio and video, industrial control, and medical monitoring.

MCU Features

Integrated 32-bit XT804 processor, operating frequency 240MHz, built-in DSP, floating-point unit and security engine
Built-in 2MB Flash, 288KB RAM
Integrated PSRAM interface, supports up to 64MB external PSRAM memory
Integrated 5-way UART high-speed interface
Integrated 2-way 16-bit ADC, maximum sampling rate 1KHz
Integrated 1 high-speed SPI interface, supports up to 50MHz
Integrated 1 SDIO_HOST interface, supports SDIO2.0, SDHC, MMC4.2
Integrated 1 SDIO_DEVICE, supports SDIO2.0, maximum throughput 200Mbps
Integrated 1 I2C controller
Integrated GPIO controller, supports up to 18 GPIOs
Integrated 5-way PWM interface
Integrated 1 Duplex I2S controller
Integrated 11 Touch Sensors

2. Temperature and humidity module

The temperature and humidity sampling sensor IC uses SHT20, a digital temperature and humidity sensor launched by Switzerland. Based on the leading CMOSens digital sensing technology, it has excellent long-term stability. Full range calibration, low power consumption, and high cost performance make this product suitable for a variety of applications.

The technical parameters are as follows:

1. Humidity measurement range: 0~100%RH
2. Humidity measurement accuracy: ±3%RH
3. Temperature measurement range: -40~125℃
4. Temperature measurement accuracy: ±0.3℃
5. Working voltage: 2.1~3.6VDC
6. I2C interface output

lugl4313820

Great idea! Very well prepared! Looking forward to seeing your excellent work soon!