A simple base experiment on Arduino by Loiseau créatif.
Code with comments :-)
The goal is to have stable, smooth and precise readings from a potentiometer connected on an analog pin of an Arduino.
I'm not an expert, there's certainly improvements to make.
This experiment can be a source of inspiration and information for Makers.
Feel free to interact on GitHub ;-)
At start I watched the YouYube Live Bar Arduino #8.
Ubi de Feo talked about Fast Smoothing of Analog Input, and showed his code in action.
This inspired me, so I took up and analyzed his code, and researched more about this topic.
Enjoy!
Methods used:
- Running Average algorythm with a FIFO data structure (First In First Out)
- Hardware RC Low Pass Filter (see the schematic image)
- Mapping filtered values
The running average algorythm seems like a good alternative to a simple average to give a smoother output and let the Arduino work on other things.
But it has one big down side: memory use.
The hardware RC Low Pass Filter on the input analog pin smoothes the signal by killing high frequencies.
You can use these components and test other values: 100nF(104) Ceramic Condensator + 10KOhm resistor.
Online Frequency Calculator
You can find additional informations here:
- 3 methods to filter noisy Arduino measurements
- Arduino Reference: analogRead()
- Arduino Tutorials: Smoothing
An additional method called Hysteresis can help you to define actions depending on range of readed values.
