My Blogs: Embedded System Dev

Embedded System

Embedded system combines circuit hardware and micro-controller (MCU) program software.

Building embedded systems is one of my hobbies. Most of my projects are based on 8-bit MCUs (such as AVR and the legacy MCS-51), a variety of digital and analog actuators and sensors, interconnected by digital buses.

My projects contains multiple phases. Starts from selecting MCU, sensor and actuator modle, studying manual; to circuit design, programming and breadboard test; and PCB design and fabrication, soldering, commissioning.

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 @ Mon, 02 Sep 2024 22:56:10 GMT

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 @ Mon, 02 Sep 2024 22:55:57 GMT

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 @ Sun, 01 Sep 2024 02:23:20 GMT

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 @ Sun, 01 Sep 2024 02:23:06 GMT

Use CNC to make PCB

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 @ Sat, 31 Aug 2024 05:01:48 GMT

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 @ Sat, 31 Aug 2024 05:00:17 GMT

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 @ Sun, 11 Aug 2024 20:26:04 GMT

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 @ Sun, 11 Aug 2024 08:16:16 GMT

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 @ Sat, 23 Dec 2023 21:06:21 GMT

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 @ Sat, 23 Dec 2023 21:05:58 GMT

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 @ Sun, 20 Aug 2023 23:00:17 GMT