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Topic starter
2021-03-15 8:42 am
Hi,
I found multiple youtube videos where people show how they use potentiometers for controling servos with an Arduino board. I see that people use different Potentiometers: 5k, 10k or 100K etc... Wy are these all other types and what is the best one to use? Witch one gives the best en smoothest results? And does the choice effect the programming?
I'm goning to build a Arduino Mega with PCA9685 for controlling 16 servos with potentiometers.
Kind Regards
Gerd
The Netherlands
2021-03-15 10:11 am
The actual resistance doesn't matter a great deal, what is most important is that you get a linear-taper potentiometer and not an audio (or "analog") tapered one. In other words, when the pot is at the center point the resistance at that point will be 50% of the total resistance on each side. These days linear-taper ones are the most common type.
As for resistance, the higher it is the less current the pot will consume from your power supply. Look at any of those circuits, the pot is always attached with one side to ground and the other side to the reference voltage (usually the power supply voltage). So the higher the resistance, the less current it is dropping.
Generally, 10K is a good all-around value.
As for the programming, if the pot is just in a resistive divider arrangement (as it is in most of those circuits) then it doesn't affect the programming at all. You are measuring the input voltage level, which the pot is controlling. The program has no idea how the voltage is being produced, it just measures it.
Adafruit distributes some nice "breadboard friendly" 10k linear pots that I find useful, they are of good quality and have a nice "feel". The "feel" or "smoothness" that the pot has is a physical property that is not easy to define in a spec sheet, but it makes a difference in the real world. You just need to try a few out to see what "feels" best to you.
If you want real precision there are a number of instrumentation potentiometers available (for a high cost), and on the real precision side, you can also get multi-turn precision pots.
Hope that helps!
😎
Bill
"Never trust a computer you can’t throw out a window." — Steve Wozniak
Sean451 reacted
Topic starter
2021-03-15 3:57 pm
Hi Bill!
Thanks for that quick respons and extra input: Good to know about the different kinds of potentiometers!
Gerd