LM35+Arduino

[Chintha]

Hi i am using Arduino Dumilnove and the connections are same as used in Lady ada tutorial.ie., inner and outer pins of LM35 are connected to 5V and GND and Middle pin is connected to Analog 0 pin ,,,

I am expecting the room temperature around 25 deg Cent and the voltage around 0.25 for LM35 (As given in  Lady ada tutorial )

Thanks,,,

[Chintha]

Hi i am using Arduino Dumilnove and the connections are same as used in Lady ada tutorial.ie., inner and outer pins of LM35 are connected to 5V and GND and Middle pin is connected to Analog 0 pin ,,, I am expecting the room temperature around 25 deg Cent and the voltage around 0.25 for LM35 (As given in Lady ada tutorial ) Thanks,,, ..

[JohnCS]

Very mysterious! Does the measured analog input value change when you hold a finger against the chip? Can you measure the output of the chip with a multimeter instead of with analog in?  That is use the power and ground from the Arduino.

How do power the board? I assume USB since you are communicating with the serial port.  Are you absolutely sure that the chip is LM35? Do you have another chip to try?

JohnCS

[Chintha]

that's a good idea , i ll change the chip

[Chintha]

that's a good idea , i ll change the chip

[Chintha]

I measured the voltage of analog pin0 , it is giving as 0.31v with multimeter.

Onemore thing ,, i am attaching a file ,, arduino code for LM35,,

val = analogRead(tempPin);   // read the value from the sensor

 temp = 30 * val / 1023 + 10;  // Convert the reading to Celsius value

But it is quite different from what we have for LM35 in Lady ada tutorial...

Last thing i have to check is changing the chip.

Thanx

[JohnCS]

Are you consistently getting AD values around 70?  Observed values around 70 seem odd. If your analog reference is 5 volts, in a 25 degree room, you should be getting AD around 50.  

Fist, with a multimeter, measure AREF to GND. Next, VIN to GND.

What is the exact measured air temperature when you take a reading?  Is there any source of heat near the chip or are you touching it?

The formula to get the voltage from the AD = VREF (expected to be 5 volts) * AD / 1024

To get temperature in C multiply by 100.

JohnCS

[CarlosOtiniano]

add other useful links, greetings

NI LabVIEW Interface for Arduino Toolkit - 

http://sine.ni.com/nips/cds/view/p/nid/209835

Getting Started With the LabVIEW Interface for Arduino

http://vishots.com/getting-started-with-the-labview-interface-for-arduino/

Ready to get started?

https://decibel.ni.com/content/docs/DOC-16204

[CarlosOtiniano]

hello such, any consultation with arduino is better than consult in the next group, also find, documentation, examples

https://decibel.ni.com/content/groups/labview-interface-for-arduino