modetest -M rockchip ❝ When connecting an EDP interface display to the motherboard, if the error “LT CR Failure” (Link Training & Clock Recovery failure) occurs, the following are possible causes and solutions: 1. Core Reasons for Link Training Failure Poor Signal Integrity The EDP signals (differential pairs) from the motherboard to the display may … Read more
Recently, RK has implemented a hardware cursor layer processed from the upper layer, with the repository located at https://github.com/JeffyCN/drm-cursor. Previously, hardware cursors like those on the RK3399 used the generic interface of libdrm, but on new platforms such as RK3568 and RK3588, it seems that the kernel does not set up a separate mouse layer. … Read more
When we submit PCB production data for prototyping, there is an option regarding the Tg value of the material on the online prototyping pricing page of the board factory. Different Tg values will affect the final prototyping costs, which means you have to pay for the Tg value of the material. So, what is this … Read more
1. Layout 10 Rules for Component Layout: 1. Follow the principle of “large first, small later; difficult first, easy later,” meaning that important circuit units and core components should be prioritized in layout. 2. The layout should refer to the schematic diagram, arranging major components according to the main signal flow direction of the board. … Read more
Project Name: Modbus Remote I/O Board – Based on STM32F103C8T6 – V1.0 Project Author: NeoMR Introduction To consolidate newly learned embedded knowledge, a handsome guy crafted a industrial control Modbus remote I/O board! This project is fully open source and relatively simple! It is meant for sharing and learning together! This project can be used … Read more
Tombstone defects on PCBs, also known as the Manhattan Bridge or bridge effect, are a type of assembly defect for surface-mounted (passive) components. This defect occurs due to inconsistent melting times of solder paste at both ends of the component, leading to uneven stress on the component. Given that these components are relatively light, they … Read more
I have a demo board with an integrated MOSFET Buck power supply. Although the circuit is simple, the layout is quite textbook-like. Here are some key design points of this circuit: 1. Phase Plane The phase plane, which is the plane connecting the inductor and the power IC, is the dirtiest signal (high current, high … Read more
Route according to the 50-ohm impedance line width, try to route from the center of the pad, keeping the lines straight and preferably on the top layer. When a bend is necessary, make it at a 45-degree angle or as an arc, preferably bending near capacitors or resistors. If routing meets the matching requirements of … Read more
Editor’s Note: The content of this article is quite concise. The first two factors are introduced using ADS simulation schematics, and those interested can follow along. Many buses have requirements for loss, so for design engineers, it is essential to understand which factors dominate the changes in loss. We often discuss the issue of loss … Read more
[Fundamentals] 3W Principle Power Supply Management and Plane Segmentation About Dead Copper (PCB Islands) Where is the Reference Plane for Routing? How to Quickly Estimate PCB Trace Resistance: Square Statistics [PCB Fabrication and Materials] Basic Knowledge of PCB Fabrication Classification of Substrate Materials for Printed Circuit Boards Classification and Selection of PCB Materials Differences in … Read more