lm34ch-nd precision temp sensor prelim results

Forum 2005-2010 (read only) Hardware Interfacing
#1

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.

#2

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

#3