Changing the Tiny Arduino clock between 1MHz and 8MHz
Simplest and Cheapest Arduino
- 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
8 Channel Relay Box
Wireless Router Home Automation
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.
16 Output Arduino Controller
ATTiny45/ATTiny85 Arduino based Camera Control
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.
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.