Make: Liquid ID Spectrometer
Resource and Parts list
Parts List
Main Components
Case
Arduino Board
You may substitute the Arduino NG for the the Arduino Diecimila - The latest version of the USB boards. Allows for automatic reset of the board by the Arduino software when uploading. Contains a low dropout power supply (which accepts 6-12V), and has overcurrent protection for the USB connection. Lots more information about the Arduino board can be found at http://www.arduino.cc/
Serial Display
Similar products are available from Matrix Orbital LK-204-25 and
Scott Edwards
Power regulator and heat sink
You will need 1 7805 5 volt regulator and a heat sink
LED and Photo Transistor
LEDs have polarity, which means they will only light up if you orient the legs properly. The long leg is typically positive, It is called the Anode. The short leg connects to GND it is called the cathode; the bulb of the LED will also typically have a flat edge on this side. If the LED doesn't light up, trying reversing the legs (you won't hurt the LED if you plug it in backwards for a short period of time). You will need 1 Red, 1 Orange, 1 Yellow, 1 Blue and 1 Infrared LED. You will also need 1IR phototransistor. I got all of my LED’s from Radio Shack.
Resistor
The project uses:
5 - 220 ohm 1/4 watt resistors
1 - 2.2K ohm 1/4 watt resistor
2 - 1K 1/4 watt resistors
1 - 18K 1/4 watt resistor
You will also need a power supply that provides 6 to 12 volts DC at about 1 to 1.5 amps to power the Arduino board, the LED’s and the display. The backlight for the display requires 5 volts at 1 amp. I used a voltage regulator IC mounted on a heat sink to drop the 12 Volts to 5 volts for the backlight. The pushbutton switches were from Radio Shack but any momentary, normally open, good looking push button switch will do. Lots more information about the Arduino board and the software development program and command reference information can be found at http://www.arduino.cc/
