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Author Topic: Bad LM35 sensors  (Read 704 times)
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Montreal - Canada
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hi,

just to let you know that I bought a pack of 5 LM35DZ sensors from ebay (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140544658004&ssPageName=STRK:MEWNX:IT

and that only 1 is reporting "somehow" a decent temperature. Another one is reporting a temperature 10 degrees under compare to the first one, and the 3 others are simply not reporting anything.

the code i'm using is the one below and it has been proven working fine as per another thread and one of my sensor:

Code:
int sample_count;
float val;
float sample_avg;
float temp;

void setup()
{
  Serial.begin(9600); // start serial communication
  analogReference(INTERNAL);
}

void loop(){

sample_count++;
val = analogRead(1);
sample_avg = sample_avg + (val - sample_avg) / sample_count;

if (sample_count>=4096){
  temp=(1.1 * sample_avg * 100.0) / 1024.0;
  Serial.print(temp,DEC);
  Serial.println("º");
  sample_count=0;
}
}


just so you know, being cheap and getting crap from china out of ebay is not helping your case! I'm learning the hard way.

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GriDo

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I was not talking to anybody, just making a statement. I've received a few bad/defective components in the last few weeks and i'm a bid tired of this. I'm well aware of the counterfeiting stuff as I'm traveling in those regions every once in a while. Sad that you get these when you believe you are ordering the  real deal.
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GriDo

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thanks for the advice,

may you give us the link of vendor ?

are you tried to write to im for refund ?
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- [Guida] IDE - http://goo.gl/ln6glr
- [Lib] ST7032i LCD I2C - http://goo.gl/GNojT6
- [Lib] PCF8574+HD44780 LCD I2C - http://goo.gl/r7CstH

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I just received two LM35DZ's (and $40 worth of other components) from the same eBay seller.

Both of my temp sensors seem to read room temperature as some random number between 20 and 40 C.  I've been pulling my hair out trying to isolate line noise.  I might be able to use them to sense a fire I suppose, but they're probably more likely to cause one.  I suppose all the other stuff I got from this wanker is junk too.


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thanks but i think that is good write the name of seller, we may do a list of "not affidable ebay seller"
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- [Guida] IDE - http://goo.gl/ln6glr
- [Lib] ST7032i LCD I2C - http://goo.gl/GNojT6
- [Lib] PCF8574+HD44780 LCD I2C - http://goo.gl/r7CstH

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