Tutorial

Build a Raspberry Pi-based air quality monitoring system with gas and dust sensors, plus a DIY air purifier using a box fan and MERV 13 filter.

续篇：固定翼与直升机/四轴的稳定性差异、上反角原理、机械效率对比，以及为什么不太看好载人四轴的发展前景。

无人机空气动力学入门：机翼升力原理、失速现象、螺旋桨工作方式、周期变距器的作用，以及为什么四轴有速度上限。

Simple web system for sharing EC2 access while the bill payer maintains control—team members can start instances via web interface with authentication.

Build cheap compute clusters on AWS using spot instances: automated system configuration, sshfs file transfer, and GNU parallel for job distribution.

A practical guide to scraping photos from Facebook groups when Graph API doesn't expose the endpoint - using Chrome dev tools, curl with cookies, grep and awk to extract image URLs from rendered HTML.

Building a web interface for MATLAB using Node.js and Express, enabling file upload, real-time status updates, and result download—useful for collaborative research and distributed computing.

Using GitHub WebHook to create a self-updating Node.js web app that automatically pulls code and restarts when you push to the repository.

Beamer Writer update: online compiling via WriteLaTeX integration and improved error messages for faster LaTeX presentation workflow.

A simple PHP script to send automatic email notifications when someone pushes to your GitHub project, using GitHub's post-receive web hooks with JSON payload parsing.