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:
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.
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.
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.
Seems still to be a problem, I had built a gadget and was just awaiting the LM35DZ, was working fine with a 10k pot generating 0-3.3V as a dummy temperature sensor, wired the LM35DZ in, reading was bouncing around between 30 and 40 C. Realised I was only supplying it with 3.3V so corrected this to 5V, still same readings, set up some tests with a fresh Nano, sensor and display on a breadboard, all the same. Put the sensor across a PP3 battery, it immediately became very hot and 7V on output pin! Started getting suspicious, read there are fakes which are actually transistors, plugged it into an old Maplin multimeter transistor test socket and it passes as a PNP transistor! Have now ordered some hopefully proper ones.
Part was "10pcs LM35DZ LM35 TO-92 nsc temperature sensor ic inductor lxPTH" sold by planet-earths (also states item location as London, but was shipped direct from China).
tamitche:
Put the sensor across a PP3 battery, it immediately became very hot and 7V on output pin! Started getting suspicious, read there are fakes which are actually transistors, plugged it into an old Maplin multimeter transistor test socket and it passes as a PNP transistor!
After you destroyed it by connecting it to your PP3 battery (which Confirms it's NOT a transistor or it would not be able to get hot as the base would be unconnected) all bets are off on what your multimeter thinks it is.