I. Introduction
The current article summarizes 28 software and hardware projects designed based on different microcontrollers (51 microcontroller and STM32). These projects cover many fields such as calculators, mobile phones, alcohol detectors, ambient temperature and humidity detection equipment, attendance systems, access control cameras, human health detectors, digital photo albums, solar water heaters, digital water heaters and smart air conditioners.
These projects demonstrate the application of microcontrollers in different fields. Through these projects, you can learn how to design and develop microcontroller-based hardware and software systems. Among them, projects based on 51 microcontrollers and STM32 involve calculators, mobile phones, alcohol detectors, ambient temperature and humidity detection equipment, attendance systems, access control cameras, human health detectors, digital photo albums, solar water heaters, digital water heaters and smart air conditioners and many other fields. These projects not only demonstrate the power of microcontrollers, but also provide examples and references for practical applications. Both beginners and experienced developers can gain valuable knowledge and experience from these projects and further expand their capabilities in the field of microcontroller development.
2. Project examples
【1】Calculator designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-0294123917169144002-1-1.html
The project uses technical principles such as the IO port, timer and LCD1602 display of the microcontroller. Among them, the IO port is used to control peripherals such as the matrix keyboard, buzzer, and LCD1602 display screen; the timer is used for keyboard scanning to ensure that key input can be accurately captured; the LCD1602 display screen is used to display the entered numbers and calculation results. .
The design idea is mainly divided into three parts: keyboard scanning, calculator operation and LCD1602 display. In the keyboard scanning part, the keyboard is scanned by timer interrupt to determine whether a key is pressed, and the number corresponding to the key is saved in the buffer area. In the calculator operation part, the data structure of the stack is used to perform calculator operations. When the operation symbol is pressed, the previously entered number is pushed into the stack and waits for the next input. When "=" is pressed, the number is taken from the stack, calculated, and the result is saved to the stack. Finally, the results are taken out of the stack and displayed on the LCD1602 display. In the LCD1602 display part, by setting the commands and data of the LCD1602, you can display numbers and operation symbols on the LCD1602.
【2】Simple mobile phone designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0263123994373975012-1-1.html
A simple mobile phone designed based on STM32 can be developed as a smart watch model to facilitate the elderly and children to wear it. The project is mainly to solve the difficulties that the elderly or children may encounter when using smart watches, such as difficulty in operation and complex functions.
In this project, the STM32F103RCT6 main control chip and SIM800C GSM module were used to realize basic functions such as sending text messages and making and receiving calls, and added functions such as ringing, answering, hanging up, and presetting text messages. When a new call is detected, the user will be notified through a buzzer, and the user can answer and hang up the call through buttons, making the operation simpler and easier to understand. The phone also provides 4 buttons to send 4 preset text messages to pre-specified contacts, which is more convenient and fast.
【3】Alcohol detector designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0206124075204259015-1-1.html
With the development of society and the improvement of living standards, people have higher and higher requirements for driving safety and family safety, and problems such as drunk driving It is also becoming increasingly prominent. For this reason, an alcohol detector based on STM32 is developed. By detecting alcohol concentration, displaying the results in real time and alarming, it can effectively avoid safety hazards caused by drunk driving.
【4】Ambient temperature and humidity detection equipment (IIC simulation timing) designed based on 51 microcontroller + SHT30
https://bbs.huaweicloud.com/forum/thread-0204124163899131015-1-1.html
The current article introduces the ambient temperature and humidity detection equipment designed based on 51 microcontroller and SHT30 sensor. The device adopts IIC analog timing communication protocol, which can monitor the temperature and humidity of the environment in real time, and display the data through the LCD display; it can be widely used in indoor environment monitoring, meteorological observation, agricultural greenhouse monitoring and other fields.
In this project, the 51 microcontroller is used as the main control chip, the SHT30 sensor is used as the temperature and humidity sensor, and the LCD display is used as the data display module. The IIC communication protocol is simulated through the GPIO port of the 51 microcontroller to realize data communication with the SHT30 sensor.
【5】Ambient temperature and humidity detection system (IIC simulation timing) designed based on STM32+SHT30
https://bbs.huaweicloud.com/forum/thread-0206124252665477025-1-1.html
This article currently introduces the design process of the ambient temperature and humidity detection system based on STM32F103ZCT6 chip design. The current system collects ambient temperature and humidity data through the SHT30 temperature and humidity sensor, and transmits the data to the STM32 chip through the analog IIC timing protocol. The STM32 chip then processes these data and displays them on a 0.91-inch OLED display so that users can easily observe changes in ambient temperature and humidity.
The main control chip of the system uses STM32F103ZCT6, which is a high-performance 32-bit ARM Cortex-M3 microcontroller with rich peripherals and memory resources to meet the needs of various applications. The temperature and humidity detection sensor uses SHT30, which is a high-precision digital temperature and humidity sensor with the characteristics of fast response, low power consumption, and high reliability.
【6】Qt uses kingbase database to store data (complete addition, deletion, modification and check of attendance system data)
https://bbs.huaweicloud.com/forum/thread-0263124333891139035-1-1.html
Currently, a classroom attendance system software is developed based on Qt (C++), which mainly uses the Kingbase database for data storage and management.
The specific functions completed are as follows:
(1) Complete functions: The software can complete the login and registration of students, teachers and administrators. Teachers can publish course information and attendance information, students can view their own course information and attendance records, and administrators can manage teacher and student information. . The software has data visualization and other functions to facilitate administrators to intuitively understand the teaching situation.
(2) Efficient and stable: The Kingbase database is used to store data, which ensures the reliability and consistency of data storage, and also improves system performance and response speed. In terms of program design, the MVC model is adopted to separate the program logic from the interface, making the program structure clear and easy to maintain and expand.
(3) User-friendly: It adopts a humanized operation interface and interaction method, allowing users to easily browse and manage courses and attendance records. Considering the security of the software, a hash encryption algorithm is used to protect user passwords.
【7】The life cycle of variables in C language
https://bbs.huaweicloud.com/forum/thread-02105124419303744002-1-1.html
In C language, the life cycle of a variable refers to the time period during which the variable exists. Understanding the memory release timing of the variable can help you design a program. Fewer problems.
During program execution, variables go through the following three stages:
(1) Definition stage (defining variables): When defining a variable, the compiler will allocate memory space for the variable. At this time the value of the variable is undefined.
(2) Usage phase (assignment, reading variables): During program execution, variables can be assigned or read. At this time, the value of the variable is determined and will change with the progress of program execution.
(3) Destruction phase (variable is destroyed): When the scope of the variable ends, the variable will be destroyed. During this process, the compiler will automatically release the memory space occupied by the variable.
【8】SQLite database completes data addition, deletion, modification and query
https://bbs.huaweicloud.com/forum/thread-0298124507395724005-1-1.html
The main function of the design introduced in the current article is to use the SQLite database to store the data uploaded by the pet feeder, and to support the addition, deletion, modification and query operations of the data. Among them, the data uploaded by the pet feeder includes parameters such as feeding interval, water temperature, and remaining weight.
Implementation function:
- Create a SQLite database table to store the data uploaded by the pet feeder.
- Implement the insertion operation of data in the database table, that is, store the data received from the pet feeder into the database.
- Implement query operations on data in database tables, including filtering according to parameters such as feeding interval, water temperature, remaining weight, etc., so that users can view data information within a specific range.
- Implement the modification operation of data in the database table, that is, you can modify the stored data uploaded by the pet feeder.
- Implement the deletion operation of data in the database table, that is, you can delete the stored data uploaded by the pet feeder.
【9】Access control camera designed based on STM32
https://bbs.huaweicloud.com/forum/thread-02108124592769233003-1-1.html
The current article introduces the access control camera designed based on STM32. This project provides a more intelligent, safe and convenient access control solution. The access control camera uses STM32F103ZET6 MCU as the main control chip, and cooperates with peripheral modules such as a 2.8-inch LCD display, OV7725 digital camera, SD card, and analog doorbell buttons to realize real-time display of camera images, doorbell-triggered photography, and picture storage.
When using this access camera, visitors only need to press the doorbell button, and the camera will automatically take photos and save them to the SD card. At the same time, users can also perform operations such as time adjustment and local picture browsing through the LCD screen, which improves the operability and user experience of the access control system.
The access control camera is designed to improve the security and intelligence of the access control system and solve many problems existing in the traditional access control system. By using a digital camera to replace the traditional cat's eye and realizing automatic photo shooting and storage functions, the security of the access control system is effectively improved. At the same time, operations such as time adjustment and local picture browsing are performed through the LCD screen, which realizes the intelligence of the access control system and improves the user experience.
【10】Human health detector designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0275124679969756005-1-1.html
The current article introduces a human health detector designed based on STM32. The device uses the STM32 series MCU as the main control chip and is equipped with peripheral modules such as a blood oxygen concentration sensor (using the MAX30102 blood oxygen concentration detection sensor), an OLED screen, and battery power supply. The equipment can be widely used in medical, health and other fields. It can help doctors and patients better understand changes in condition and improve treatment effects and quality of life. The device can also be used in health management, sports monitoring and other scenarios to help users understand their physical condition and maintain a healthy lifestyle.
In the project, KEIL was used as a development platform and tool to collect the human body's heartbeat and blood oxygen concentration parameters through the blood oxygen module, and display the current heartbeat and blood oxygen concentration through the OLED screen. At the same time, through indicator analysis, the collected data is compared with normal indicators to analyze the health status of the person being tested. The collected data can be transferred to the mobile phone APP for processing via Bluetooth or WIFI, allowing users to understand their physical condition at any time.
This design uses STM32 as the main control chip, combined with a blood oxygen concentration sensor and an OLED screen, to collect and display human health data, and analyze the collected data to determine the health status of the person being tested. At the same time, the design uses Bluetooth or WiFi to transfer the collected data to the mobile APP for processing.
【11】Digital photo album designed based on STM32
The https://bbs.huaweicloud.com/forum/thread-02108124967477379010-1-1.html
project is a digital photo album designed based on STM32. It can decode and display mainstream pictures through the LCD display, and supports bmp, jpg, gif and other formats. Users can switch pictures through buttons or touch screen, and can also rotate the display, and can adaptively center the display. Small-size pictures are displayed in the center, and large-size pictures are automatically reduced and displayed (outside the screen range). Pictures are taken from SD card.
【12】Solar water heater designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0218125111816332002-1-1.html
This project uses the STM32F103C8T6 microcontroller as the core processor, combined with multiple sensors and actuators, to realize automatic control of solar water heaters. By monitoring and analyzing various parameters such as light, temperature, and water level, water pumps, solenoid valves and other equipment are automatically controlled to achieve efficient, safe, and reliable operation of solar water heaters.
【13】Digital water heater designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0296125025587823020-1-1.html
The project currently introduced is a digital water heater designed based on the STM32F103ZET6 series MCU. The temperature and working status of the water heater are displayed through the display screen, the temperature change of the water heater is detected through the PT100 sensor, and the heating process is realized through the electric heating plate to achieve control. water heater temperature purpose.
【14】Smart air conditioner designed based on STM32
https://bbs.huaweicloud.com/forum/thread-0218125198043493007-1-1.html
As people’s living standards continue to improve, their requirements for the comfort of the living environment are also getting higher and higher. As an important household appliance, air conditioning has become an indispensable part of modern families. This article introduces a smart air conditioning design based on STM32, which can automatically adjust the temperature according to the ambient temperature.
[15] Call libvlc through GTK to develop a video player under (Linux) ubuntu
https://bbs.huaweicloud.com/forum/thread-0260120987830294095-1-1.html
This project implements a video player based on GTK and libvlc. Use GTK to create a GUI interface and use libvlc to play videos. Users can watch the video by selecting the video file and then launching the player. VLC is a free, open source cross-platform media player that supports playing almost all common audio and video formats. Originally developed by French students in 2001, it has become a very popular media player available on multiple operating systems such as Windows, macOS, and Linux.
libvlc is one of the core libraries used by VLC media player. Provides a set of application programming interfaces (APIs) that allow developers to easily embed VLC-like media playback functionality into their own applications. libvlc can be integrated with a variety of programming languages and frameworks (such as C, C++, Python, Java, .NET, etc.), so it is widely used in various media-related projects.
【16】Smart granary system design based on STM32
https://bbs.huaweicloud.com/forum/thread-0251121310318982005-1-1.html
With the improvement of grain quality requirements and changes in storage methods, the monitoring and control of the granary environment have become increasingly important. In the past traditional management, ventilation, moisture-proofing and other operations required regular manual operations, with low accuracy and efficiency. The use of embedded technology and intelligent control algorithms for monitoring and control can not only grasp environmental changes in real time, but also respond quickly.
This project chooses STM32F103RCT6 as the main control chip, uses DHT11 temperature and humidity sensor and MQ9 combustible gas detection module for data collection, and displays it locally on the display in real time. The WiFi module is used to achieve data communication and remote control with mobile phones, allowing users to understand the environmental conditions of the granary at any time and perform corresponding operations. At the same time, by connecting the relay to control the ventilation fan and buzzer alarm, intelligent temperature and humidity detection and combustible gas concentration detection are realized.
【17】STC89C52+DS18B20 realizes ambient temperature detection (digital tube displays temperature)
https://bbs.huaweicloud.com/forum/thread-0243121316881177004-1-1.html
Temperature detection is one of the common application scenarios in many fields such as industrial automation and production lines. Timely and accurate temperature monitoring plays a very important role in ensuring production safety and improving production efficiency. In the modern electronics manufacturing industry, the use of electronic components such as microcontrollers and sensors for temperature detection has become a relatively mature technical solution.
This project selects STC89C52 microcontroller and DS18B20 digital temperature sensor. By reading the temperature value output by the sensor, after calculation and processing, and displaying the result on the digital tube, real-time monitoring and display of the ambient temperature is achieved. Among them, the STC89C52 microcontroller is the main control chip, responsible for receiving and processing data from the digital temperature sensor, and displaying the temperature value through the digital tube.
[18] Real-time display of heart rate detection based on STC89C52+PulseSensor heart rate sensor
https://bbs.huaweicloud.com/forum/thread-0265121330233011005-1-1.html
Currently, a heart rate detector is implemented based on STC89C52 microcontroller and PCF8591, PulseSensor heart rate sensor, SSD1306 OLED display and other components. The detector can collect the analog signal output by the heart rate sensor, calculate the real-time heart rate value after AD conversion, and then transmit the heart rate value to the OLED display for display through the IIC protocol. Users only need to fix the heart rate sensor on the body and start the heart rate detector to conveniently monitor their heart rate in real time.
This project has a wide range of applications and can be used in health management, fitness exercises, medical treatment and other fields. At home, people can use this heart rate monitor to monitor their own heart rate in a timely manner and effectively manage and control their health; in gyms or fitness coaching centers, coaches can use this heart rate monitor to monitor athletes' heart rate changes in order to target The training plan can be adjusted accordingly to improve the training effect; in medical institutions, medical staff can use the heart rate monitor to monitor the heart rate of patients, detect abnormalities in time, and provide a strong basis and reference for patient treatment.
【19】Gravity sensing vending machine system design based on STM32
https://bbs.huaweicloud.com/forum/thread-0265121395891313007-1-1.html
With the continuous development of smart IoT technology, people's lifestyles and consumption habits are also changing. Nowadays, more and more people are accustomed to new consumption models such as online shopping and self-service shopping, so smart retail self-service cabinets have emerged.
This project designs and develops a smart retail self-service cabinet based on the STM32 main control chip. It monitors the weight changes of the goods in the container through a gravity sensor and interacts with the mobile phone through the WiFi communication module. The user can enter the account password and the cabinet door will automatically open. After the user picks up the goods, he closes the cabinet door and locks the door. The system determines the goods taken by the user based on the weight change and automatically deducts the fee from the account. At the same time, users can also check consumption flow and product inventory through the mobile phone, and perform operations such as replenishment and recharge.
Smart retail self-service cabinets have a wide range of application scenarios and can be used in various scenarios such as shopping malls, supermarkets, hotels, airports, and stations. Through self-service shopping, consumers' consumption experience and shopping efficiency can be improved, while the labor costs and logistics costs of merchants can also be reduced.
【20】OpenCV (C++) creates pictures and draws graphics (rectangles, circles, text, line segments, etc.)
https://bbs.huaweicloud.com/forum/thread-0243121483718019010-1-1.html
OpenCV is a cross-platform computer vision library based on an open source license that provides a rich and extensive set of image processing and computer vision algorithms. OpenCV supports a variety of programming languages, including C++, Python, Java, etc., and can run on Linux, Windows, Mac OS and other platforms.
OpenCV can draw various geometric shapes, text and curves on images, as well as adjust, crop and rotate images. These functions provide great help for image analysis and processing.
Here are some applications where OpenCV can draw images:
(1) Image annotation: Add annotations or annotations to images. For example, in target detection or image classification tasks, the detected targets are marked by drawing boxes, labels and other information on the image.
(2) Display after processing: For example, during image processing, a comparison chart can be drawn on the image before and after processing to visually display the effect of image processing.
(3) Real-time display: Real-time display effect is achieved by continuously drawing on the screen, such as outputting the processed video stream in video processing and rendering it on the screen in real time.
【21】Electric vehicle controller designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-0230121569022841003-1-1.html
With the rapid development of social economy, people have higher and higher requirements for energy conservation and environmental protection. Electric vehicles have gradually become the focus of market attention due to their non-pollution, low noise, low use cost and other advantages. At the same time, with the continuous advancement and application of science and technology, the technical level of electric vehicles is also constantly improving.
In order to better meet the market demand and the requirements of technological progress, this project designs an electric vehicle controller based on the 51 microcontroller. It mainly includes two key parts: electric vehicle control and drive. Among them, the control part uses 51 microcontroller as the control core, and the electric vehicle can realize forward and backward driving, left and right steering, acceleration and other operations through programming. The drive part uses the L298N driver chip to drive the DC motor. The currently designed electric vehicle supports lithium battery power supply and supports buttons to realize operations such as forward and backward driving, left and right steering, and acceleration. The motor uses a DC motor and the driver chip uses L298N.
【22】Infrared remote control designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-0265121655118767005-1-1.html
Remote controls are one of the indispensable electronic products in modern life. Currently, there are many types of remote controls on the market with a wide range of applications. The NEC infrared remote control protocol is one of the most widely used protocols at present. Almost all TVs, air conditioners and other household appliances support this protocol.
This project is based on the 51 microcontroller to design an infrared remote control that supports the NEC protocol and implements receiving, decoding and sending functions. The user transmits the signal by pressing the corresponding button, and the infrared emitting diode emits an infrared signal. The controlled device receives the signal through the infrared receiving head, and then decodes and performs the corresponding operation.
【23】Breathing light designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-0263121739989142011-1-1.html
Breathing light is a common LED lighting effect that can simulate changes in human breathing and make the light look softer and more natural. The 51 microcontroller is a widely used microcontroller with the advantages of small size, low power consumption, and low cost. It is very suitable for controlling LED breathing lights. The breathing light of this project will use PWM (Pulse Width Modulation) technology to control the LED brightness to achieve the effect of a breathing light.
In this project, a 51 microcontroller will be used as the main controller to control the breathing light through programming. Code will be written in C and compiled and debugged using the Keil C51 integrated development environment. Use Proteus simulation software for circuit design and simulation to ensure the correctness and stability of the circuit.
【24】Flower water lamp design based on 51 microcontroller design
https://bbs.huaweicloud.com/forum/thread-0278121828581585008-1-1.html
Flowing water lights are a common LED light effect and are widely used in stage performances, festival celebrations, party performances and other occasions. In modern smart homes and electronic products, fancy running lights are also widely used. By adjusting the order and time of turning on and off, various cool lighting effects can be achieved and the user experience can be enhanced. As a common embedded development platform, the 51 microcontroller has the advantages of small size, low power consumption, and strong programmability. It is very suitable for developing fancy running lights and other embedded applications.
Water lamps are widely used in the following scenarios:
Stage performance: Flowing lights can be used in stage backgrounds, music MVs and other occasions to create cool and dynamic visual effects in conjunction with music and dance. Festival celebrations: In traditional festivals such as the Spring Festival, Mid-Autumn Festival and other occasions, patterned water lanterns can be used for lanterns, lanterns and other decorations to add a festive atmosphere to the festival. Party performances: In various evening parties, parties, gatherings and other occasions, fancy water lights can be used for stage effects, music and light shows, etc. to enhance the atmosphere and fun of the entire event. Smart Home: Flowing water lamps can be used in home lighting control to realize functions such as remote control, timer switching, automatic adjustment, etc., to enhance the sense of technology and humanization of the living environment.
【25】Underground gas monitoring system designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-0257121913134531009-1-1.html
The underground gas monitoring system is a very important part of coal mine production safety, preventing underground gas explosion accidents and ensuring the personal safety of coal miners. Due to the special underground environment, a special monitoring system is needed to monitor key indicators such as gas concentration in real time and alarm in time so that measures can be taken to deal with it.
Methane gas, also known as biogas, is a light hydrocarbon gas whose main component is methane (CH4) and also contains small amounts of ethane, propane, etc. It is formed through microbial action or chemical reactions of coal in underground coal seams and rocks such as mudstone. In underground projects such as coal mines, gas is often a dangerous gas. If improper measures are taken, a gas explosion accident may occur.
The underground gas monitoring system based on the 51 microcontroller can detect the gas concentration through the sensor, convert the detected data through AD and send it to the microcontroller for processing, and then display it through the LCD display. If the gas concentration exceeds the preset threshold, the system will automatically activate the alarm device to warn. At the same time, this system has the characteristics of wide application, low cost and high reliability.
Under the current background of increasing environmental awareness, coal enterprises and governments have an increasing demand for underground gas monitoring systems, and the market potential of the system is huge.
【26】Thermistor temperature measurement system based on 51 microcontroller design
https://bbs.huaweicloud.com/forum/thread-0257121999877180011-1-1.html
The current article introduces the design process of a thermistor temperature measurement system based on 51 microcontroller, which is used to monitor the ambient temperature in real time and alarm when the temperature exceeds the preset threshold. Since the thermistor temperature measurement technology is used, no external temperature sensor is required, making the system simple in structure and low in cost.
The main control chip uses STC89C52, which has good stability and reliability and is suitable for application needs in industrial control and other fields. The ADC acquisition module uses the PCF8591 module, which can easily convert and collect the thermistor temperature data, improving the accuracy and practicality of the system.
The system displays the temperature value through a 4-digit digital tube and sets the temperature upper limit threshold through buttons. When the temperature exceeds the threshold, a buzzer will alarm to remind the user to pay attention to changes in ambient temperature.
In the project, the thermistor and PCF8591 module are mainly used.
Thermistor (Thermistor) is a material-based resistance element whose resistance value changes correspondingly with changes in temperature. Normally, the resistance value of the thermistor decreases as the temperature increases, and conversely increases as the temperature decreases. This characteristic is called a negative temperature coefficient (NTC) or a positive temperature coefficient (PTC).
The working principle of the thermistor is based on the temperature-sensitive properties of the material. In the thermistor, there are many conductive particles. When the temperature increases, the degree of excitation of the conductive particles and the ions in the material increases, resulting in an increase in the number of conductive particles, so the resistance value decreases; conversely, when the temperature decreases, the conductive particles The number becomes smaller and the resistance value increases.
【27】Digital thermometer based on 51 microcontroller design
https://bbs.huaweicloud.com/forum/thread-0278122087157540015-1-1.html
A digital thermometer is an electronic measuring instrument widely used in daily life and industry. It is used to detect ambient temperature and convert it into a digital signal for display. With the development of modern technology, digital thermometers have gradually replaced traditional mercury thermometers and other methods, with the advantages of fast response, high accuracy, and portability.
Digital thermometers designed based on 51 microcontrollers are specifically used for temperature detection in manufacturing industries, such as temperature controllers, oven temperature controls, food processing, industrial furnaces and other fields. The temperature is collected through a digital temperature sensor such as DS18B20. A commonly used microcontroller control chip such as STC89C52 is used to display the temperature data with a 4-bit common anode digital tube. The upper limit temperature threshold is set through buttons. Once the temperature exceeds the threshold, the system The buzzer will be triggered for alarm prompts, thus ensuring precise temperature control and safety.
The DS18B20 is a digital temperature sensor produced by Maxim Integrated. Using the 1-Wire bus interface, only one data line is needed to realize data transmission and power supply at the same time. The main features are high accuracy, fast response speed, small size and low price. It is widely used in various temperature measurement occasions.
The temperature range that DS18B20 can measure is -55℃ +125℃, and the accuracy is ±0.5℃ ( within the range of -10℃ +85℃). It integrates a temperature sensor, A/D converter and digital signal processing circuit, which can directly output digital temperature values.
The working principle of DS18B20 is to use the influence of temperature on the resistance value of semiconductor materials, convert the temperature into a resistance value, and then convert the resistance value into a digital signal output through an A/D converter. The 1-Wire bus interface can realize the series connection of multiple DS18B20 sensors, and only one controller is needed to read the temperature data of multiple sensors at the same time.
In the thermistor temperature measurement system, the DS18B20 sensor can be used to measure the ambient temperature and transmit the temperature value to the controller for processing and display.
【28】Bus LED screen designed based on 51 microcontroller
https://bbs.huaweicloud.com/forum/thread-02116122174305668002-1-1.html
In order to improve the real-time and accuracy of bus stop information, it is convenient for passengers to know the bus arrival information in time, thereby improving the convenience and comfort of bus travel. Traditional bus arrival information is achieved through manual announcements or static stop signs. This method has problems such as untimely, inaccurate, and inconvenient information. The current design is based on the STC89C52 microcontroller and the MAX7219 dot matrix LED driver module. The bus LED screen uses SYN6288 to broadcast the arrival information via voice, which can display the arrival information more accurately and improve the efficiency and convenience of bus travel.
The STC89C52 microcontroller controls the MAX7219 dot matrix LED driver module to convert the information to be displayed into a dot matrix image, and then controls the 2*8 LED display screen through the MAX7219 dot matrix LED driver module to display it. At the same time, through the SYN6288 voice module, the arrival information is converted into voice announcements for the convenience of passengers. In this way, passengers can not only see the arrival information, but also hear the voice announcement, which improves the real-time and accuracy of the information and facilitates passengers to understand the bus arrival information in a timely manner.