# Potentiometer/code error **URL:** \ **Category:** Mega 2560\ **Created:** [November 1, 2026, 9:42am UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063 "2026-11-01T09:42:48Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![anon789456](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/anon789456/32/1289128_2.png) [@anon789456](https://forum.arduino.cc/u/anon789456)\ **Post date:** [November 1, 2026, 9:42am UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/1 "2026-11-01T09:42:48Z")
Attempting to make a simple code that gives the Voltage(V) of leg3 on my potentiometer (POT) (just a beginner ). However, when the POT reads near its min (0.1 ohm), my serial monitor reads 522 and at its max (10k), 1023. But, moving the pot from 0% to 85% of its range, returns 522 - 585, then instantly starts climbing to 1023 (586 -1023) for the remainder of its %. Nothing is wrong with the breadboard or POT. Even tried using diff gnd pins, and A# pins. I put in the the code I used but I've already recoded it a few times. Does anyone know how to fix this situation or possibly explain what I'm doing wrong, it'd be greatly appreciated! ```arduino int readPin=A3; float leg1=0; void setup() { Serial.begin(9600); } void loop() { leg1=analogRead(readPin); Serial.println(leg1); delay(100); } ``` ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [November 1, 2026, 9:50am UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/2 "2026-11-01T09:50:42Z")
Welcome to the forum Seeing a schematic of your setup would help Is it a linear pot or a logarithmic pot ? ---
**Author:** ![PaulRB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paulrb/32/216330_2.png) [@PaulRB](https://forum.arduino.cc/u/PaulRB)\ **Post date:** [November 1, 2026, 10:04am UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/3 "2026-11-01T10:04:15Z")
> [@anon789456](#): > > Nothing is wrong with the breadboard or POT Please explain why you say that. You said you are a beginner (or at least I think that's what you meant to say, because I have never heard of a beginner pot). Have you tried a different pot? Or a different breadboard? Or at least a different part of the breadboard. Even though you haven't shared details of your wiring, I can immediately imagine a likely cause. You are using a breadboard with a non-breadboard-compatlble Arduino, a Mega. That forces you use use Dupont cables, and these are notorious for their unreliability. Have you tried testing out at least replacing each one you are using? ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [November 1, 2026, 10:06am UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/4 "2026-11-01T10:06:52Z")
Does the breadboard have continuous power strips along its edges or do they have gaps in the middle ? If the latter then have you got connections to each side of the break ? ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [November 1, 2026, 12:48pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/5 "2026-11-01T12:48:03Z")
> [@anon789456](#): > > the Voltage(V) of leg3 ```arduino Serial.println(leg1); ``` but your code says leg1 ---
**Author:** ![sonofcy](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/sonofcy/32/1283617_2.png) [@sonofcy](https://forum.arduino.cc/u/sonofcy)\ **Post date:** [November 1, 2026, 1:26pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/6 "2026-11-01T13:26:56Z")
What kind of pot, linear, log? ---
**Author:** ![JCA34F](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jca34f/32/340148_2.png) [@JCA34F](https://forum.arduino.cc/u/JCA34F)\ **Post date:** [November 1, 2026, 2:14pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/7 "2026-11-01T14:14:29Z")
Sounds like you have a "volume control" pot with a logarithmic taper that more closely matches the non linear response curve of human hearing, a type "A" pot. Look at the back of the pot and post the lettering there (if any). ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [November 1, 2026, 4:11pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/8 "2026-11-01T16:11:53Z")
What are the characteristics of a linear pot versus log pot, that @anon789456 can observe on the DMM? ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [November 1, 2026, 4:14pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/9 "2026-11-01T16:14:21Z")
At one end of the track a small movement of the pot wiper will produce a small change in resistance whilst at the other end of the track the same size of movement will produce a much larger change in resistance ---
**Author:** ![EmilyJane](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/emilyjane/32/821537_2.png) [@EmilyJane](https://forum.arduino.cc/u/EmilyJane)\ **Post date:** [November 1, 2026, 4:15pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/10 "2026-11-01T16:15:45Z")
![Screenshot 2026-11-01 at 10.15.14 AM](https://europe1.discourse-cdn.com/arduino/original/4X/0/9/4/094f119393a8a1d96746bdac91fd3fa29e34d82e.png) ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [November 1, 2026, 4:16pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/11 "2026-11-01T16:16:59Z")
Is this observable with a DMM? (no graphic output) ---
**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\ **Post date:** [November 1, 2026, 4:17pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/12 "2026-11-01T16:17:38Z")
Log or linear, it shouldn't start from 522.. ---
**Author:** ![EmilyJane](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/emilyjane/32/821537_2.png) [@EmilyJane](https://forum.arduino.cc/u/EmilyJane)\ **Post date:** [November 1, 2026, 4:18pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/13 "2026-11-01T16:18:37Z")
Not nearly as easily. ---
**Author:** ![JohnLincoln](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@JohnLincoln](https://forum.arduino.cc/u/JohnLincoln)\ **Post date:** [November 1, 2026, 4:23pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/14 "2026-11-01T16:23:12Z")
> [@xfpd](#): > > Is this observable with a DMM? - Set the potentiometer to it's mid position. - Measure the resistance between the wiper and each end. - For a linear potentiometer the two values should be similar. - For a logarithmic potentiometer, one value should be about ten times the other. ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [November 1, 2026, 4:24pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/15 "2026-11-01T16:24:12Z")
Describing pot-turns-versus output might help @anon789456 Mark five spots along the pot dial and map them... ```arduino 1 2 3 4 5 6 Linpot 0 1 2 3 4 full Logpot 0 1 1 3 5 full ``` ---
**Author:** ![EmilyJane](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/emilyjane/32/821537_2.png) [@EmilyJane](https://forum.arduino.cc/u/EmilyJane)\ **Post date:** [November 1, 2026, 4:25pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/16 "2026-11-01T16:25:48Z")
Yeah, I counted that as graphic output, albeit paper and pencil. ---
**Author:** ![JohnLincoln](https://avatars.discourse-cdn.com/v4/letter/j/7ba0ec/32.png) [@JohnLincoln](https://forum.arduino.cc/u/JohnLincoln)\ **Post date:** [November 1, 2026, 4:28pm UTC](https://forum.arduino.cc/t/potentiometer-code-error/1466063/17 "2026-11-01T16:28:34Z")
> [@anon789456](#): > > Attempting to make a simple code that gives the Voltage(V) of leg3 on my potentiometer I don't know how the pins of you potentiometer are numbered, but I would have thought that the wiper would normally be designated as pin2. The wiper is the one that I would have connected to the Arduino analogue input.