Looking for a way to detect dissolved oxygen levels? If you raise fish, this and a ph sensor are two important things to monitor (and of course, temperature), and an Arduino is the ideal platform to build upon. The Sensorex DO1200 ($139) outputs a <1mv – 54 mv signal indicating DO levels. Use
analogReference(INTERNAL1V1); //Mega & Mega 2560
or
analogReference(INTERNAL); //328p based
to set the top of the input range to 1.1v.
Connect it to one of your analog pins. Very simple to read, just like a potentiometer. Just connect the plus wire (usually red) to your analog input, and the minus wire (black) to Arduino Gnd.
So:
//GND(black original cable) //A3(red original cable)
int analogPin = 3; // sensor+ connected to analog pin 3
int val = 0; // variable to store the value read
void setup()
{
Serial.begin(9600); // setup serial
analogReference(INTERNAL1V1); //MEGA 2560
}
void loop()
{
val = analogRead(analogPin); // read the input pin
Serial.println(val); // debug value
delay(500);
}