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.

--by Captdam @ 2023-12-17 04:02 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.

--by Captdam @ Sun, 20 Aug 2023 23:00:17 GMT GMT


MODBUS与MODBUS RTU协议简介。这篇博客展示了MODBUS RTU请求与响应数据包的结构,并展示了如何使用AVR汇编对进行CRC-16计算。

--by Captdam @ Sun, 20 Aug 2023 22:45:46 GMT GMT


Bearweb是一个为个人网站与小型组织设计的轻量级的数据库驱动PHP网站架构。Bearweb使用简单的数据库与代码结构,致力于降低网站维护难度与成本。 这个页面简单介绍一下Bearweb的特点与开发过程。

--by Captdam @ Sun, 02 Jul 2023 07:26:17 GMT GMT


Bearweb是一个为个人网站与小型组织设计的轻量级的数据库驱动PHP网站架构。Bearweb使用简单的数据库与代码结构,致力于降低网站维护难度与成本。 这个页面简单介绍一下Bearweb的核心处理流程。

--by Captdam @ Sun, 02 Jul 2023 07:26:17 GMT GMT


Bearweb是一个为个人网站与小型组织设计的轻量级的数据库驱动PHP网站架构。Bearweb使用简单的数据库与代码结构,致力于降低网站维护难度与成本。 这个页面主要用于介绍Bearweb的工作方式与底层架构。

--by Captdam @ Thu, 25 May 2023 07:35:16 GMT GMT

OpenGL Issues

Inconsistencies I encountered during OpenGL and OpenGL ES dev.

--by Captdam @ Mon, 01 May 2023 20:03:09 GMT GMT

AVR Naked Interrupt Service Routine

Using naked interrupt service routine during AVR dev

--by Captdam @ Sat, 12 Nov 2022 10:09:00 GMT GMT

AVR Software UART Tx

AVR UART Tx in software for ATtiny series

--by Captdam @ Sun, 23 Oct 2022 07:41:59 GMT GMT


通过配置AVR单片机的fuse bits,并对AVR的内部RC时钟进行校准,使AVR单片机达到所需要的工作状态

--by Captdam @ Sun, 23 Oct 2022 06:38:56 GMT GMT



--by Captdam @ Thu, 14 Jan 2021 10:28:18 GMT GMT

Arduino (ATmega328P) bootloader


--by Captdam @ Thu, 17 Jan 2019 12:56:19 GMT GMT

MSC-51 and ultrasonic sensor

Distance measure using HC-SR04 ultrasonic sensor and MSC-51 MCU in assembly language.

--by Captdam @ Thu, 20 Dec 2018 21:50:16 GMT GMT



--by Captdam @ Thu, 20 Dec 2018 21:50:16 GMT GMT