Error analysis and positioning A database cluster is used in the project. When using it, it is found that the project is running and the database has not been operated for a period of time. If the database is operated again after a period of time, the following error will appear on the console. Failed […]
Tag: time
51 microcontroller + DS1302 design an electronic clock (LCD1602 displays time)
1. Preface An electronic clock is a device that can accurately display time. It is widely used in homes, offices and public places, providing people with convenient and accurate time information. This project designs an electronic clock based on 51 microcontroller, using DS1302 as the RTC clock chip, LCD1602 as the display screen, and connecting […]
STM32Timer + basic timer
1. Basic overview of timers 1. Principle of software timer It turns out that when we use the 51 microcontroller, we use a __nop()__ to delay The delay function we use through software is inaccurate and subject to many uncertain factors. 2. Timer principle: ratio between counts Because the use of software delay is affected, […]
FreeRTOS_Software timer (Timer)
Directory title 1. Software timer characteristics 2. Guarding tasks 3. Software timer API 3.1. Create software timer 3.2. Callback function 3.3. Delete timer 3.4. Start/stop timer 3.5. Modify the timer period 3.6. Reset timer (Reset) 3.7. Timer ID 1. Software timer features Using a timer requires configuring timer period, callback function, and type (one-time, automatic […]
C language data structure-time complexity and space complexity
1. What are time complexity and space complexity? 1.1 Algorithm efficiency Algorithm efficiency analysis is divided into two types: the first is time efficiency, and the second is space efficiency. Time efficiency is called time complexity, while space efficiency is called space complexity. Time complexity mainly measures the running speed of an algorithm, while space […]
[SCM Graduation Project] [jj-009] Intelligent Curtains | Multi-Function Curtains | Automatic Curtains | Timed Curtains | Light-Controlled Curtains
1. Basic introduction Item name: Design of intelligent curtain system based on microcontroller Design of multifunctional curtain system based on single-chip microcomputer Design of automatic curtain system based on single chip microcomputer Design of timer curtain system based on microcontroller Design of light-controlled curtain system based on single-chip microcomputer Project name: Curtain Microcontroller type: STM32F103C8T6 […]
Excel in the workplace: Get rid of manual counting and use it to increase work efficiency 10 times
In the workplace, we often have the need to count data based on specific conditions. For example, counting the number of people in a certain department, or judging whether records that meet the conditions exist in the data table. At this time, the countif function is simply not easy to use. So, today I will […]
RuntimeError: Sizes of tensors must match except in dimension 1. Expected size 58 but got size 57 fo
An error occurred: When using yolo v5n for network training, the input size used is 900*900. When connecting the Feature Map of the 11th layer and the 6th layer at the 12th layer Concat, there is a problem of different dimensions. After running, the following error message appears: RuntimeError: Sizes of tensors must match except […]
Vue uses websocket to implement real-time data push and publish, subscribe and reconnect single sign-on functions.
Requirements: Use websocket to implement publishing, subscribing, network disconnection and reconnection, and account squeezing after single sign-in without using plug-ins. 1. Single sign-on (only one of the same account is online at the same time, multiple user logins are prohibited) Implementation: After the user logs in, the token token is obtained and stored locally. It […]
Springboot2.x integrated lettuce connection redis cluster reports timeout exception Command timed out after 6 second(s)
Original/Zhu Jiqian Background: Recently, I was doing a stress test on a newly developed Springboot system. I found that when I first started the stress test, I could access data from the redis cluster normally. However, after a few minutes of pause, and then when I continued to use jmeter to perform the stress test, […]