Hi Everyone:

I'm really new at Arduino so, please pardon my ignorance in this question.

I've been working on a simple circuit and using the Arduino with an LM35 temp sensor. The code works just fine to provide me the correct temperature output but, I really don't understand the equation that is used with the ADC.

When I take a voltage reading on the sensor at approximately 20 degrees C, the voltage output from the sensor is about 204mV. The equation: temp * 0.48828125 provides me the 20 degrees C. However, when I do the math and multiply the 204mV x the 0.48828125 is will not provide an answer of 20 degrees C.

Would someone please explain how the LM35 works with the ADC, relative to the calculations? My numbers don't jive and I really want to understand how the LM35 output relates to the equation and ADC to provide the 20 degrees C temp that is on the Serial Monitor.

Thanks in advance for helping a real newbee!