Arduino Mega and potentiometers.

Hi everyone, just wondering if there would any problem with drawing too much current if an Arduino Mega was simultaneously connected to 6 potentiometers? (1k or 10k). Thanks in advance!

tetris911: Hi everyone, just wondering if there would any problem with drawing too much current if an Arduino Mega was simultaneously connected to 6 potentiometers? (1k or 10k). Thanks in advance!

i think it's ok.. What are those potentiometers supposed to control ? 8) 8)

Linear actuator feedback potentiometers as part of a stewart platform.

tetris911:
Hi everyone, just wondering if there would any problem with drawing too much current if an Arduino Mega was simultaneously connected to 6 potentiometers? (1k or 10k). Thanks in advance!

Ohm’s law could have answered that for you. Worst case 1K pots draw 5 mA @ 5 vdc X 6 pot = 30 MA, which is no problem being supplied by the 5V pin

Hi, I'm having the same sort of question, only I'm using 16 10K potentiometers. Would this mean I could theoretically use up to 80 of these potentiometers @5vdc since the Arduino supplies 40Ma?

And if I'd use capacitors for decoupling and diodes to prevent current fly-back, would this significantly help me with a more stable signal? ( my potentiometers are up to 100 ft / 33 meters away from my arduino over a double shielded XLR cable) Or should I be fine without them?

Thanks.

The analog pins are spec'd to perform accurately for sources of 10k or less, which would suggest a maximum pot value of 20k (whose output resistance at mid-travel is 10k). I would generally use 10k pots as they are commonly available. Any lower value is simply increasing power consumption for no gain. Less than 1k and you'd risk seeing significant voltage drops in the supply wiring to the pots leading to some error.

You would add 100nF caps to ground on the relevant analog pins in a noisy environment and to reduce sliding-noise from the pots.

Thurcke: Hi, I'm having the same sort of question, only I'm using 16 10K potentiometers. Would this mean I could theoretically use up to 80 of these potentiometers @5vdc since the Arduino supplies 40Ma?

Not relevant - the pots are powered from the 5V supply, not an Arduino pin. USB supplies 500mA.

Arduino pins have an absolute max rating of 40mA - so you would perhaps not take them beyond 20 or 25mA continuous in practice.

Ah, great. Thanks for the confirmation. I'll keep in mind that I could use the 100nF caps in case my signals are noisy. Thanks.

Thurcke: Hi, I'm having the same sort of question, only I'm using 16 10K potentiometers. Would this mean I could theoretically use up to 80 of these potentiometers @5vdc since the Arduino supplies 40Ma?

Much more than that, because 40mA is the limit per output pin, not the power supply. With USB power (for example) you can do 1000 of them! You're going to need more analog pins!

(PS: you should never go to 40mA - "40mA" is a number that needs deleting from the collective consciousness, 40mA is where damage starts, not a working current).

Hi, if you are going to use 16 or 80 potentiometers, in my opinion you should provide a separate 5V supply for them.
If you project is complex enough to use that many pots then I’d be serious about my power supplies.
Question, what are you guys using so many pots for, just curious.

Tom… :slight_smile:

I'm measuring angle/speed for playground swings. With the data I count the number of swingperiods and that's where the music starts in MaxForLive ;-) I'm building 16 swings for a number of musicfestivals this summer.

It does have it's own 5v switching powersupply.