Hello All,
I have 6 ntc thermistors and 6 10k resistors are connected in series and am trying to measure the temperature. But due to some noise am getting a fluctuation in the temperature. so am putting an 0.1uF capacitor between the NTC and Resistor to smoothening the output in constant.
but my question is, is it okay if i connect all the 6 NTC to the same Capacitor and raising the value of capacitor to 0.6uF or is it necessary to use separate capacitor for all the 6 NTC thermistors.
Surely, If you use just 1 capacitor, that will connect all 6 NTCs together - so you won't be able to read them independently?
Is that what you want?
If you're worried about the number of hardware components, you could do the smoothing in software ...
Thankyou for the answer, but should i use 0.6uF or 0.1uF capacitor.
How can i do smoothening in arduino code ?
Google "moving average" or "running average" ...
So how did you determine the 100nF value originally? Apply the same method to the combined circuit ...
I have done average but due to high powersupply the noise is more and affecting the NTC. So i have decided to put Capacitors. I want to know should i use 0.6uF or 0.1uF capacitor for considering all the 6 NTC's.
Should you not be doing something to address your noisy power supply?
It's always best to prevent the noise in the first place, rather than try to filter it out after the event!
How do you intend to connect these 6 NTCs? Show your schematic.
So how did you determine the 100nF value originally? Apply the same method to the combined circuit ...
Hello, I have done a schematic same like this but the 10uF is not included in my circuit.
one more question from my side like example, i have used 6 NTC sensors so is it necessary to use individual 0.1uF cap for all sensors ?
Yes
Thankyou, Got it !
Which Arduino are you using.
If you use an Uno, and power the thermistors from 3.3volt (your diagram), then you get potential instability, because the result now depends on temp and supply variations. For a thermistor, pull up voltage and Aref voltage must come from the same point (ratiometric preservation). Grounding is also very important. Thermistor ground can't be shared with other devices, like on a breadboard.
Leo..
I am using Arduino Due, i have powered the 3.3V to resistor and connected the thermistor 1 end to resistor and other end to ground.
Yes, the Due is a 3.3volt board, so your setup seems right.
Leo..
yeah also i am stuggling to minimise the space of my pcb board after the arrangement of components, can you suggest the minimise pcb designing using all the components, since i am doing plugin pcb board for the arduino.
Google "Arduino Mega Proto shield".
Leo..
You only have 6 resisors and 6 capacitors. If you use 0603 size components you can make it very small.
So, again, why not do the filtering in software?
As @jim-p said, 0603 components take up very little room.
Have you looked at resistor & capacitor networks - ie, multiple resistors and/or capacitors in a single package ?
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