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Topic: lm34ch-nd precision temp sensor prelim results (Read 665 times) previous topic - next topic

optique

Hi,

I finally got this thing hooked up. Sensor hooked up to arduino's +5v and ground, with sensor output going to analog input pin 3 through a 10k resister. I am outputting the reading through Serial.print to the serial monitor. I know this thing outputs a voltage proportional to temp. Reading the sensors output to ground reads appx 0.77V at room temp.

Not having a thermometer or even ice makes testing this thing kind of pointless, but I should have it tomorrow.

Question: I am trying to know if this thing is working. Is this reasonable?

At 72 F. ambient room temp:
Sensor output  = 0.8V
Arduino reads 155

I will repeat tests tomorrow with a thermometer and ice.

Best Regards,
Steve.





walterr

I _think_ the LM34 reads +5 to +300 F with a linear 10mV/degree F. Here is the code I'm using to turn it into degrees F:

 int  tempRead = 0;
 float  temperature;
 
 tempRead = analogRead( tempPin );    // read the value from the temperature sensor
 temperature = (5.0/1024)*tempRead; // scale the raw value to a floating point voltage
 temperature *= 100; // Sensor reports 0.01V/F
 temperature -= 5.0; // sensor starts at 5 F
 temperature *= 100; // include 2 digits of precision
 tempRead = temperature; // right most 2 digits are decimal portion


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