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hey guys.
i am new to all this and well i have an LM335 which i want to connect to my MCU and display the temp,
I am not realy sure how to set it up properly, what i have done is connected it like this attached picture.. 3.3k connected to +5 and other end to cathode and gnd to anode.
i measure the voltage on the output but i dont see any change, rgardless of wat the temp is. could you guys please help out a little,
Hi,
IF the voltmeter shows changes on Cathode Voltage vs Temp ... It's a SOFTWARE problem !
so, please, think to show us your program !!!
IF Not Verify the LM335 Pinout ... FIRST.
Alain
yea buddy checkout the attached image.. i havnt really connected it to the ADC yet. i just want to see if it does change the voltage according to temp..Quote:
Originally Posted by Acetronics
Hmmmm,
Also remember the LM335 HATES to be reverse connected !!! ... did you ???
Alain
Is your meter good enough to measure 10 mV changes? Because that is how much the voltage changes per degree C. Per degree F is more like 5.5 mV.
Also, if your 5V has too much noise on it, you will not see the small voltage changes either. So make sure that the voltage being used to power the sensor is really clean or filtered well.
With the resistor you are using, you are only pulling 600 uA of current. If you measuring device does not have a very high impedance, it will also affect the output voltage. So try lowering the resistor to 2.2k or even 1k. You will still only be drawing a couple of milliamps.