mega help!

Using Arduino Project Guidance
1

Hello
I'm new to this forum ..
I'm actually using an arduino mega 2650 and have been trying to make a thermo meter using the lm35 temperature sensor
( holding the sensor such that I can read the label
The left leg was connected to 5v pin ' the middle was connected to analogue pin0 and the right was the ground)
I used the same code I was using on arduino uno ...
But the reading on the mega was 499.0 degrees
450.0 degrees 208.0 degrees and so ...any suggestions ?!

2

.any suggestions ?!

Post the program and a circuit diagram for a start

3

the diagram and the code are in the attachments .

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4

Please read this before posting a programming question and post the code using code tags to make it possible to copy/paste it to an editor.

5

You mention the LM35, but you post code and a picture of the TMP36.
?
Leo..

6

For LM35

http://playground.arduino.cc/Main/LM35HigherResolution

The LM35 only produces voltages from 0 to +1V. The ADC uses 5V as the highest possible value. This is wasting 80% of the possible range. If you change aRef to 1.1V, you will get almost the highest resolution possible.

// To change aRef to 1.1V, you use the command "analogReference(INTERNAL);"
// INTERNAL1V1: a built-in 1.1V reference (Arduino Mega only)

// Here's an example sketch using 1.1 as aRef:

float tempC;
int reading;
int tempPin = 0;

void setup()
{
  analogReference(INTERNAL1V1);
Serial.begin(9600);
}

void loop()
{
reading = analogRead(tempPin);
tempC = reading / 9.31;
Serial.println(tempC);
delay(1000);
}
7

I know what I mentioned was different. The reason is that I wasn't at home and I needed help permanently.
Thanks for help guys and I really appreciate your replies.

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