All blogs

Machine Code Generated by AVR-GCC

In this article, a number of experiments are used to examine the output machine code generated by AVR-GCC. Description is given for possible reasons AVR-GCC generates machine code in this way.

AVR-GCC, C language, disassembly, compiler, ABI, AVR, ISA, Application Binary Interface, Instruction Set Architecture, Stack, Memory layout, Static variable

--by Captdam @ Nov 18, 2024

分割PDF文档

将大尺寸PDF文件切割为数个小尺寸页面以方便打印，适合处理地图与工程图纸

切割, PDF, 放大, 切割大尺寸文件, Web应用

--by Captdam @ Nov 12, 2024

My ATtiny experience

This blog will introduce ATtiny chips in DIP / SOIC packages and with SPI-based ICSP interface that I have been used in my projects.

AVR, ATtiny, Embedded system, ATtiny25, ATtiny24, ATtiny441, ATtiny261, ATtiny2313, ATtiny48

--by Captdam @ Nov 12, 2024

我的ATtiny记录

这一篇博客主要讨论一下我玩过的基于SPI的ICSP编程头的DIP与SOIC封装的ATtiny。

AVR, ATtiny, 嵌入式系统, ATtiny25, ATtiny24, ATtiny441, ATtiny261, ATtiny2313, ATtiny48

--by Captdam @ Nov 12, 2024

Tiling PDF

Divide large PDF into tiles on multiple page to allow print on small-size paper, suit for map and civil drawing

Tiling, PDF, Enlarge, Divide large file, Web app

--by Captdam @ Nov 2, 2024

工程图PDF标题栏与目录生成器

生成PDF工程图，合并PDF文件，添加文字、图片与自定义标题栏，并生成目录。

PDF, 工程图, 标题栏, 浏览器程序

--by Captdam @ Sep 21, 2024

Engineering drawing PDF & titleblock & index generator

Merge, add text, pictures and custom titleblock to PDF engineering drawing, and generate index.

PDF, Engineering drawing, titleblock, Web app

--by Captdam @ Sep 20, 2024

68HC11打印ASCII字符串

这篇文章阐述字符串在内存中的结构，并讲解如何在电脑上通过C语言和单片机上通过汇编打印字符串。这篇文章将使用68HC11作为汇编的例子.

68hc11, 6800, 单片机, ASCII, 字符串, 内存结构, printf, C, 汇编

--by Captdam @ Sep 2, 2024

Print string on 68HC11

This article illustrates string structure in memory and how to print string on PC using C and on microprocessor using assembly. Assembly language of 68HC11 is used as example.

68hc11, 6800, microprocessor, ASCII, string, memory structure, printf, C, Assembly

--by Captdam @ Sep 2, 2024

AVR Naked Interrupt Service Routine

Using naked interrupt service routine (ISR) in AVR development

AVR, ISR, interrupt service routine, ISR_NAKED, Assembly, avr-asm

--by Captdam @ Sep 1, 2024

AVR裸中断

在AVR开发中使用裸中断

AVR, ISR, 中断, ISR_NAKED, 汇编, avr-asm

--by Captdam @ Sep 1, 2024

This blog shows how I use KiCad to design a PCB, then use FlatCAM to generate the G-code for a CNC to engrave on copper plated board. This blog also discusses the challenges I encountered and my solutions.

PCB, CNC, KiCad, FlatCAM, Embedded system, PCB prototyping, Gerber

--by Captdam @ Aug 31, 2024

使用CNC制作PCB

这一篇博客将展示我如何使用KiCad制作PCB工程文件并使用FlatCAM生成G-Code，最后使用CNC在覆铜板上雕刻出电路。这一篇博客还会讨论我所遇到的一些问题和我的解决方案。

PCB, CNC, KiCad, FlatCAM, 嵌入式, PCB打样, Gerber

--by Captdam @ Aug 31, 2024

N沟道场效应管设计与二极管设计的电平转换器

介绍N沟道场效应管设计与二极管设计的电平转换器。这篇博客将会介绍两种设计的工作原理，提供贴片PCB走线与示波器时序图，并对比相互优缺点。

电平转换器, 嵌入式系统, 电压, N沟道场效应管, 二极管, 2N7002, LL4148, 电路设计, PCB走线

--by Captdam @ Dec 23, 2023

NMOS and diode based level shifter design

Introduce two different level shifter for logic circuit design: the NMOS-based design and the diode-based design. This blog will introduce the working principle of both design, provide PCB layout for both of them using SMD, provide timing diagrams using scope for both implementation, and compare the pros and cons of them.

Level shifter, Embedded system, voltage, NMOS, diode, 2N7002, LL4148, circuit design, PCB layout

--by Captdam @ Dec 23, 2023

Understanding MODBUS RTU

Introduction to MODBUS and MODBUS RTU protocol. This blog presents the format of MODBUS RTU packet, including the request from master to slave and the response form slave to master. This blog also shows how to ccompute the CRC-16 value for MODBUS packet in AVR assembly language.

MODBUS, MODBUS RTU, PLC, serial, industry control, CRC

--by Captdam @ Aug 20, 2023