Where's the error in the following circuit/code ?
Some time ago i got various sensors . One of those was the kty 10-6 (3 pieces). At the beginning i could not find any datasheet or examples about this temperature sensor. So i got an LM35 which was very simple to setup as it is linear. Now after various months i finally found the proper datasheet and the Mathematical equation to get the proper resistor values.
KTY 10-6 (this is the datasheet link)
I found out that it is similar to the kty81-210
(Vcc 5+)--+-->2.7k--+-->kty81-110-->(GND) | | +->100nF--+-----> ADC0 (Analog Port 0)
As i have no 2.7k Ω resistor i used a 2200 ohm resistor.
the capacitor is 100nf i think: IJ63 is on top of the enclosure.correct?
As this thermistor is not linear and i always wanted to use the proper mathematical formula to calculate the temperature, this is the best solution. Based on what i read in the kty10-6 datasheet i changed some values like the resistor and the beta(a) value. the alpha(b) .00788 seems to be the same in both sensors.
float resistor = 2200; // changed float temp = analogRead(A5); float ukty = 5*temp/1023.0; float a = 0.00001937*1000; // changed float b = 0.00788*1000; float c = 1000-resistor*ukty/(5-ukty); float delta = b * b - 4 * a * c; float delta1 = sqrt (delta); float x2 =(-b + delta1)/(2 * a); float temp1 = x2 + 25 ;
Is the calculation correct?
I ask beacuse even if its really hot these days .. i don't think there are 132-135°Celsius.The formula is for celsius.
Even if i don't use this formula but use other simpler calculations (linear) i always get over 130-140°Celsius
If i touch the sensor the reading increases... as expected.
I tested on all analog pins.
I use the arduino micro.
I use it with a i2cLCD.
It's usb powered.
Nothing else is connected.
If i measure the resistor on the proto board when everything is turned off i read it as 1200ohm... the cap?
Why do i get 120 to 140 as a temperature value?
I just closed a post on electronics stack wich describes how to increase the thermistors resolution with resistors. found it
If someone knows how to change my circuit to read temperatures from -10/-20 to +40/+50 i would be very happy. this would duplicate the resolution. i think in my zone the temperatures will never go lower than -20 or higher than +50 ° Celsius.
I buyed 3 of those, i know they are cheap. I know about the nice DS##### Temp sensor which is perfect for the microcontrollers. But i want to get this one to work also.