I want to built a wifi car without using micro contoller, due to the limited GPIO availability on the wireless router, a 74HC595 Shift Register is needed to expand its outputs.

This is a 74HC595 Shift Register library for Lua running on wireless router flashed with OpenWRT, it may run in any linux-based embedded system. It can be used to shift out data from either the most (i.e. the leftmost) or least (rightmost) significant bit.

This is a very simple GPIO read/write functions for Lua running on linux-based embedded system, it is based on Arduino digital input/output syntax.

Only four functions are available: pinMode, digitalWrite, digitalRead & delay

Update: Added pin_direction_status() function on 16 Oct 2015

This is a Queuing System project requested by a clinic asistant which allows the doctor enter number from a keyboard and display it on a 32x16 LED panel.

This project uses two Arduino, the first Arduino functioned as a SENDER which included a PS2 keyboard and a mini LCD for number input. While the other Arduino is functioned as a RECEIVER which will trigger a "ding-dong" tone and display number on the 32x16 LED panel.

The SENDER uses a PS2 keyboard instead of USB keyboard, USB keyboard will cost higher since it require a USB host shield. You should get a Matrix keypad (please use google translate) in case the PS2 keyboard is not available in the market.

These two Arduino (SENDER & RECEIVER) is connected via a CAT5e network cable, the CAT5e cable provide power to the RECEIVER and also transfer data between two Arduino.

This project provides step by step approach to driving a Dot Matrix Display (DMD) Panel with an Arduino. The DMD is a 512 pixels single colour LED display arranged in 32x16 layout, a 16 pin (2x8) IDC connector is used to interface with Arduino.

In order to drive the 32x16 Dot Matrix Display Panel from Arduino, the DMD library for Arduino is required. You can download it from Freetronics GitHub.

The Freetronics DMD library is able to write letter and text on the display board with limited function, variable string and text centering is not supported. Yeah! now you can use my code to write variable string on the display board and centering it horizontally.

Updated: DMD2 library is released, this library is currently in BETA release.

这是为谋诊所设计的排队叫号机，计数器只需显示两位数。此叫号机使用了两片Arduino，一个安置在房内用来输入编号，称之为发送器，另一个则安装在房外，用来显示编号，称之为接收器。发送器是通过串口发送信息给接收器。

发送器连接了一个PS2键盘来完成输入，当然也可以使用USB键盘，不过必须添加一个USB Host Shield，这样将会增加成本。如果没办法取得PS2键盘，建议使用矩阵键盘。发送器也应用了一个小型LCD，用于显示编号，当然还能显示更多的相关资料。

接收器用了一片32x16像素的矩阵LED单元板，用来显示从串口取得的相关数据。接收器也安装了一个“铃铛”报知器，每当接收到来自发送器的数据，都会温馨提醒一下。

I have many seven segment modules in my hand. Each module consists of 5 digits and each digit is controlling by individual HEF4094 shift register. As shown in figure above is the seven segment module.

HEF4094 is an 8-stage serial shift register. Data is shifted on the LOW-to-HIGH transitions of the CP (Clock) input. The product data sheet is available here.

HEF4094 operates over a recommended VDD power supply range of 3 V to 15 V referenced to VSS (usually ground). There is also 74HC4094 available which operates at 2V to 6V.

This is a very simple Arduino project which control the 16x32 RGB LED Matrix Panel via an 16pin IDC cable. The Arduino will continuously sending 5 set colours (Red, Green, Blue, White, Black)  to the LED Matrix Panel that allow the technician to find out which part of the LED Matrix Panel is malfunction.