Sensor TMP 36 LOVE O METER is giving really low values

Hello guys.

I have this issue regarding project 3 LOVE O METER. Everything is done according to instructions, but the result is minus C degrees. In a logical sequence I checked everything - code, formulas, wires etc. And then I noticed that the value given by the sensor is really low(around 60) and therefore the chain afterwards produces low results in degrees C. It reacts to my finger when I touch it by some values, but from minus something degress it increases to minus little bit less :smiley:

My theories about this issue are:

  1. Sensor is not working properly.

  2. I should use different scale(not 0-1023 - 1024 possible results but something else).

  3. Something else.

For example this is one line from Serial Monitor : Sensor value: 55 , Volts: 0.27,degrees C: -23.14

I calculated that for 23 degrees C in my room I should have 150 Sensor value.

Can it be some other issue regarding voltage? I am powering the Arduino via USB.

Still if I change the voltage in the equation - it is not enough Sensor value(around 60) with 3 V in the circuit or with 9 V...

But still something in the sensor itself when lower voltage enters it?

Check if they did give you the TMP35 or LM35.
If so, remove the “- 0.5” in the maths line.

It is TMP 36 my sensor. Yes, I have done this already(the maths) when I remove the - 0.5 in the equation there is a proper result - around 24-25 degrees in the room, around 34 when I touch the sensor. But still... Is this a proper solution to the case. And this also means that there will be a problem when I want to measure below 0 degrees.

Or this sensor has minus value as well. For example sensor value can be - 50?

Now I have done what you suggested in the program and something strange happened. I removed the - .5 from the code, and the sensor started to give Sensor Value around 150 (around 70 degrees C).

I tought HOORAY it is giving proper value and again included the - .5 to the equation. Non sence. Again it started to give Sensor value around 50-60.

After that I removed the -.5 from the equation - at first few lines Sensor is giving low Sensor Value and some seconds after it starts to give around 150 Sensor Value.

Sensor value: 42 , Volts: 0.21,degrees C: 20.51
Sensor value: 39 , Volts: 0.19,degrees C: 19.04
Sensor value: 43 , Volts: 0.21,degrees C: 21.00
Sensor value: 47 , Volts: 0.23,degrees C: 22.95
Sensor value: 147 , Volts: 0.72,degrees C: 71.78
Sensor value: 150 , Volts: 0.73,degrees C: 73.24
Sensor value: 150 , Volts: 0.73,degrees C: 73.24
Sensor value: 151 , Volts: 0.74,degrees C: 73.73