Sunday, 09 December 2012 15:27

## Changing the Tiny Arduino clock between 1MHz and 8MHz

This article shows how to make a simplest & cheapest Arduino. The clock speed is running at 1MHz even though you select 8MHz internal clock. This is because the Div8 fuses bit of the new ATtiny85 is enabled by default, therefore 8MHz divided by 8 is 1MHz. In order to resolve this problem, we nee to disable the Div8 fuse bit using a AVR programmer.

Here I provide a method to switch the Tiny Arduino clock speed between 1MHz and 8Mhz by using a Arduino Duemilanove as an ISP programmer.
Published in Tutorials
Sunday, 09 December 2012 13:56

## Simplest and Cheapest Arduino

Here we use a ATTiny85 (can be ATTiny45, ATTiny44) to make an Arduino just for US3.00, so we name it as Tiny Arduino.

Tiny Arduino have only eight pins as shown in figure above, Pin4 is ground (Gnd), Pin8 is 5V (Vcc), Pin1 is Reset, Pin2 and Pin3 originally used to connecting the Crystal. In order to utilize all the IO, the internal oscillator (RC Oscillator) is used to replace the external clock which require a crystal. Therefore the Tiny Arduino is now come with five IO. Below shows the Arduino IO functions.
• There are five IO, each IO can be Input or Output
• Among the five IO, two of the IO can perform as PWM
• Among the five IO, three of the IO can perform as Analog Input
I2C may require to extend the features of Tiny Arduino.
Published in Blog
Thursday, 06 December 2012 16:33

## 最简单又最便宜的Arduino

Tiny Arduino只有八个接脚（Pin)，Pin4为接地(Gnd)，Pin8为5V(Vcc)Pin1为复位(Reset)，Pin2和Pin3原本用来连接Crystal，为了要尽量用完全部IO，所以使用内部振荡(RC Oscillator)，因此Tiny Arduino共有五个IO。以下是Tiny Arduino的功能。
• 五个IO，各个IO可以设成输入(Input)或者输出(Output)
• 其中两个IO可以设成PWM
• 三个IO可以设成Analog输入

Published in Chinese
Wednesday, 03 October 2012 16:26

## 8 Channel Relay Box

This is a 8 channel relay box that the input connect to a controller allow it to control large loads like home appliances.

I'm using this relay box for a snooker centre to control snooker table lamps. The lamps consists of 6 pieces 20W and 3 pieces 10W fluorescent lamps, total of power consumption is 150W per table. Picture below shows the snooker table lights for the snooker centre.
Published in Projects
Tuesday, 25 September 2012 20:53

## Wireless Router Home Automation

This project eliminate the use of an expensive Wifi/Network Shield but still able to control home appliances from any where. You may already own a wireless router which support OpenWRT or else you can get a very cheap wireless router such as WR703N for this project.

In order to eliminate install many packages on the router, I am using HTML and Javascript for the web interface, while hardware interface is using Lua which is come with OpenWRT. The whole process is just install a serial driver (see step below) to make the instruction simple & keep the router free of resources.
Published in Projects
Sunday, 02 September 2012 14:52

## Connecting ULN2803 Line Driver to Arduino

If you are using Arduino (or any other TTL device) to control 4 channel relays or more, I would suggest to use ULN2803 Line Driver instead of Transistors or FETs. You can use ULN2003 which is much more cheaper if you plan to use not more than 7 channel relays.

The ULN2803 Integrated Circuit (IC) is a "Eight-way Line Driver". It allows you to interface TTL signals (5v) with higher voltage/current (50V/500ma) loads.

As shown in figure 1 and figure 2, an Arduino is control 8 relays, one using ULN2803 line driver and the other one using transistors, both circuit are equivalent.

Published in Blog
Sunday, 19 August 2012 12:13

## 16 Output Arduino Controller

The is a sketch for Arduino to communicate with computer or embedded device (eg. wireless router) using serial communication.

Arduino Duemilanove have 14 digital IO pins (2 digital IO used by serial) and 6 analog IO pins. Here I coded the analog IO as digital IO, so we can easily get 16 digital IO.
Published in Projects
Sunday, 29 July 2012 12:58

## ATTiny45/ATTiny85 Arduino based Camera Control

Digisnap 2000 (Electronic shutter release) is powerful but expensive. This project replacing Digisnap 2000 with very simple function.
Published in Projects
Sunday, 29 July 2012 11:04

## Control Arduino via PHP (EasyPHP)

The Arduino Duemilanove (not Arduino Uno) is control by a computer over the network or internet via PHP. This article assumed that you already install WAMP web server & Arduino driver in your computer.

My Arduino Duemilanove is connecting to the USB port of my computer, the USB serial com port is detected as COM4.

Published in Blog
Sunday, 29 July 2012 10:25

## ATTiny45/ATTiny85 Infra-Red PS2 Keybard (ATIR)

Original project is on http://www.circuitcellar.com/avr2006/winners/AT3296.htm published in AVR contest 06 by Steven Savage. But the link is not available any more.

The interface plugs into a PS2 keyboard port on the PC and accepts commands from the infrared remote. I'm using an ordinary DVD remote (38KHz) to control my computer.

The original schematic is not correct, I had make the correction for PC Data & PC Clock of SV1.
Source Code and Compliled Hex file: infra-red ps2 keybard atir.zip
Published in Blog
Page 5 of 5