Day 1

醒的好早，突然想到了做Arduino的点子，上班前就下单了两套微雪电子的e-Paper ESP8266 Driver Board

CRC - Cyclic Redundancy Check is widely used in data transition. According to wikipedia.org, A CRC-enabled device calculates a short, fixed-length binary sequence, known as the check value or CRC, for each block of data to be sent or stored and appends it to the data, forming a codeword.

在之前遇到的数据中，由于同一部件的可替换不同产品，造成了同一行出现了2次及以上同样的字段和属性值，而只需要其中的一个以及对应值即可，此文记录下处理的过程。

几乎在所有的无线路由器基本上都有自带一个按钮，简简单单2个作用：
1.短按WPS连接
2.长按恢复出厂

Many people are curious on how to clone access card for convinience or just for fun. Most access system with RFID verify visitors with UID in the access card. It's the first 4 bytes hex data of Block 0 in Sector 0.
Follow the steps bellow to clone an access card.

The last post shows how to use MTools to read money data on Sector 3.
Here's the tutorial to show how to charge mifare 1k card with regular rule on 2 blocks.

NFC has been widely used on Android Pay, Apple Pay and Device Connection.
With NFC on Android Phone, it's even easy to read datas in the mifare card, such as Metro Card, RFID Parking card and etc.
This article shows how to use NFC as a mifare reader to read the amount remaining in the card.