Monday 18 March 2013

First post, One and a half sugars please

So this is my first blog its more of a log for myself, of my experiments and projects so i know what ive done and how ive done it.


Thermometer:

The temp sensor used is TMP36 the middle signal pin connects to analog input 0 on the arduino.

It outputs 10millivolts per degree c... to allow minus temps it has a 500mV offsett meaning 25c = 750mV, 0c = 500mV..

Convert this from a digital signal analog signal to degrees using maths functions, then displayed using the IDE debug window though a serial connection.





The code used was..


int temperaturePin = 0;    // pins and corresponding inputs are assigned

void setup()    // runs once 
{
    Serial.begin(9600); // initiates serial connection with comp 
}

void loop() // loops over and over
{
    float temperature = getVoltage(temperaturePin);    // float stores the voltage from
                                                                                             // temperaturePin

    temperature = (temperature - .5) * 100;                    // because the offset.. 0c = 500mV
                                                                                            // and each degree is 10mV..
                                                                                            // converts voltage into temp
                                                                                            
    Serial.println(temperature);                                        // prints the result in degrees
    delay(1000);                                                                 // delay
}

    float getVoltage(int pin){                                           // converts from 0 to 1023 digital range
    return (analogRead(pin)  * .0048828814);              // to 0/5 volts each 1 dig range = 5mV
}






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