Java Implementation of 99 Multiplication Table — Using For Loop and Recursion

Java Implementation of 99 Multiplication Table For Loop public class ninenine { public static void main(String[] args){ for (int i=1;i<10;

Python Formatted Output (% and format Usage)

Integer Output %o—Octal (Base 8) %d—Decimal (Base 10) %x—Hexadecimal (Base 16) Floating-Point (Decimal) Output Formatted Output >>> awsl = 2.333 >>> p

What is dB? How to Calculate dBm, dBc, dBi, and dBd, and What Are Their Differences?

This article explains dB as a logarithmic unit for ratios, using 10log for power and 20log for voltage/current. It defines dBm against 1 mW, dBc against carrier power, dBi against isotropic antenna, and dBd against dipole (dBi minus 2.15). Understanding these units and calculations enables accurate analysis and design of electronic and communication systems.

[Study Notes] Trigonometric Functions (Sine, Cosine, Tangent)

The sine function and cosine function are the two most fundamental and significant functions in trigonometry. They have extensive applications in desc

Open-Source 140W+65W Buck-Boost PD3.1 Fast-Charging Module (2C+1A Ports), IP6557+IP6538,

An open-source 205W buck-boost fast-charging module based on IP6557 and IP6538 is presented, offering 140W on one Type-C port with PD3.1 support and 65W on the second Type-C and Type-A ports. Maximum conversion efficiency reaches 96.7%. Full documentation and design files are provided, enabling users to replicate a cost-effective charger.

A Simple Unboxing and Review of EastTester(中创) ET4410 Desktop Digital LCR Meter

The article reviews the EastTester ET4410 LCR meter, purchased for 1,199 yuan. It outlines key specifications, including 10Hz-100kHz frequency, 0.2% basic accuracy, DCR and electrolytic capacitor modes, TFT display, and calibration functions. Practical tests show accurate measurements for resistors, capacitors, and inductors, though low-resistance readings are limited. A list sweep mode bug is identified, with a firmware update provided. Readers gain cost-performance insights, usage guidance, and awareness of measurement limitations when choosing this instrument.

STM32F407-Based LVGL Project Template for MSP3526 Screen (FreeRTOS and Bare Metal Editions)

Article presents porting LVGL to STM32F407 with a 3.5-inch MSP3526 LCD (ST7796, FT6336U) using SPI+DMA, providing FreeRTOS and bare-metal project versions. It covers wiring, performance figures (~9 FPS full-screen, >30 FPS partial after overclocking), code examples, and download resources, helping readers implement embedded GUI displays effectively.

STM32 based OLED screen driver with software or hardware I2C support (HAL library)

This article presents a complete STM32G474 HAL library driver for 0.96-inch SSD1306 OLED displays with 4-pin I2C interface, supporting both hardware and software I2C via simple macro configuration. It enables displaying English, integers, floating-point numbers, Chinese characters, images, binary and hex values, plus drawing points, lines, rectangles, circles, ellipses, and triangles with multiple fonts. Step-by-step STM32CubeMX setup instructions for both I2C modes are included, making integration straightforward.

Synchronous Rectification Buck-Boost Digital Power Supply Based on STM32

This article presents an open-source four-switch Buck-Boost digital power supply based on STM32G474, supporting Type-C PD and DC input up to 48V10A and 450W. It includes schematic, PCB, firmware, and 3D model files. The design offers adjustable output, OLED display, protections, and host monitoring, achieving up to 94.3% efficiency and low ripple. Users can access calculations and source code.