Arduino Projects of note

• Arduino temperature controlled PC Fan.

• Tutorial: Arduino and the I2C bus – Part One

• Arduino Mini Pro + RTC DS3231 + I²C LCD backpack / I²C scanner + LCD clock demo code: [1]

• cheap good rtc http://www.dx.com/p/ds3231-high-precision-real-time-clock-module-blue-3-3-5-5v-222910#.VGg-R_nF98E

RTC

I have some zs-042 RTC , it has a DS3231 RTC and what looks like an ATmega32 on it.

LCD

Liquid Crystal Display

Some notes:

• http://tronixstuff.com/2011/01/08/tutorial-arduino-and-monochrome-lcds/

Voltage Comparator Based Sensor

Picked up a soil moisture sensor from Deal Extreme ad 2.23 USD$

http://www.dx.com/p/soil-humidity-moisture-detection-sensor-module-blue-black-white-200142

It's based on a lm393 voltage comaparator. Many variation exist, for things like sound and light aswell.

This is an analog to digital sensor NOT a 1 wire sensor, so it soaks up an analog pin.

Resources:

Arduino Code example:
http://arduino-info.wikispaces.com/Brick-LightSensor-Analog-Digital

LM 393 Datasheet:
http://www.ti.com.cn/cn/lit/ds/symlink/lm293-n.pdf

From analog to digital

So you got a bunch of cheap sensors, but they are all voltage oriented, like lm 939 and tmp36 and lm35, but you want to hook up a pile of them. wouldn't it be great if you could "convert" the voltage changing sensors to 1 wire or I2C ?

By using a buss ( like I2C ) you can attach many sensors to a single pair of arduino digital pins.

You can! Some notes so far below.

Analog to I2C

http://www.ti.com/lit/ds/symlink/ads1000-q1.pdf