Nov 10, 2014

A test for my Arduino working with NRF24L01+PA transceiver

There are two computers, one is called Joker and the other is called Batman. They use Morse code to communicate. The microcontroller is Arduino and the wireless transceiver is NRF24L01+PA. I find that sometimes it works fine especially at night when few people are in the lab, but sometimes transmission failed (both of them can not talk to each other or just one-way communication works). Not sure if the reason is the interference from wifi.

Sep 29, 2014

A simple office desk safety alarm system

Something you need: 1 arduino microcontroller, 1 breadboard, 1 LED, 1 PIR sensor and some wires.

May 26, 2014

A shortcut to convert PDF to EPS

Just find a good way to convert pdf file to eps. This is quite useful when you edit a paper with Latex. Before we do it, we need to download the Texshop (

To convert pdf → eps (Mac OS X will only do (e)ps → pdf & pdf → ps),

- open the pdf in TeXShop, choose the 'Selection' tool in the Preview window toolbar

- select the desired rectangle (or all, either with ⌘-A or manually),

- choose 'Preview>Save Selection to File...', & save as eps."