RGB LED STRIP + POTENTIOMETERS FOR SELECTING COLORS

Projects Programming
1

Hello everybody,
i've written down some code for manage 3 potentiometers to change the strip color.
The code is

#define REDPIN 10
#define GREENPIN 11
#define BLUEPIN 3
int rPin = 2; 
int gPin = 3; 
int bPin = 4; 
 
void setup() {
  pinMode(REDPIN, OUTPUT);
  pinMode(GREENPIN, OUTPUT);
  pinMode(BLUEPIN, OUTPUT);
}
 
 
void loop() {
  int r, g, b;
  Serial.begin(9600); 
    analogWrite(GREENPIN, analogRead(gPin)/4);
    analogWrite(BLUEPIN, analogRead(bPin)/4);
    analogWrite(REDPIN, analogRead(rPin)/4);
     Serial.print("verde ");
     Serial.println(analogRead(gPin)/4);
     Serial.print("blu ");
     Serial.println(analogRead(bPin)/4);
     Serial.print("rosso ");
     Serial.println(analogRead(rPin)/4);
     delay(300);
 }

The serial monitor give what I expect, a value from 0 to 255 while potentiometer is totally turned off or totally turned on.
The problem is "in the real life" because 1 color never change with different position of the potentiometer (the other 2 colors work perfectly).
I don't understand why, I've also tried a simple configuration connecting directly each color of the strip with arduino, but same problem.
I've also tried changing the potentiometer with a new one but nothing.
it seems that 1 digital pin output is always at max
Any idea?

2

Not all the pins you have chosen are capable of PWM outputs. Look at your board if the pin number has a ~ next to it you can use it with analogWrite, otherwise you can't.

3

The problem is "in the real life" because 1 color never change with different position of the potentiometer (the other 2 colors work perfectly).

But you aren't going to tell us which colors are which.

void loop() {
  int r, g, b;
  Serial.begin(9600);

What are the unused local variables for? Why are you initializing Serial on every pass through loop?

4

The board is an arduino UNO so if i'm correct the pwm ports are 3-5-6-9-10-11

about
int r, g, b; you're right,
The code was a little different in the first version because I've used 4 potentiometer and the last one was used to make a crosscolorfader effect if >20 and the potentiometer value was used to select the speed of fading. But I' had the same problem while using the rgb selectors so I've deleted the code of the 4th potentiometer but i've missed the r,g,b declaration for the crosscolorfader for cycles.
About which colors are which...
rpin -->redpin-->pin 10 digital output
gpin -->greenpin--> pin 11 digital output
bpin -->bluepin --> pin 3 digital output

The problem is on the green, but if i change the cable on the digital pin with another color I've the same problem with the new color. (indeed).
Hope to be more "understandable" in this post.

5

errata corrige
if I exchange the digital pin (for ex 10 with 11) the problem still on the same color. So it is not a problem of the port

6

I've find short circuit on the link of the green color.
Now everything works correctly.
Sorry for the inconvenience.
I'll post the code for RGB color chooser + Cross colorfader with potentiometer for fadertime hope to be useful to someone.

#define REDPIN 10
#define GREENPIN 11
#define BLUEPIN 3
int faderPin = 0;
int rPin = 2; 
int gPin = 3; 
int bPin = 4; 
int fadeSpeed=0;
int r,g,b ;
void setup() {
  pinMode(REDPIN, OUTPUT);
  pinMode(GREENPIN, OUTPUT);
  pinMode(BLUEPIN, OUTPUT);
}
 
 
void loop() {
 
 if (analogRead(faderPin)>20){
  fadeSpeed = analogRead(faderPin);
  analogWrite(REDPIN, 0);
  analogWrite(BLUEPIN, 255);
  analogWrite(GREENPIN, 0);
 
  // fade from blue to violet
  for (r = 0; r < 256; r++) { 
    analogWrite(REDPIN, r);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
  // fade from violet to red
  for (b = 255; b > 0; b--) { 
    analogWrite(BLUEPIN, b);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
  // fade from red to yellow
  for (g = 0; g < 256; g++) { 
    analogWrite(GREENPIN, g);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
  // fade from yellow to green
  for (r = 255; r > 0; r--) { 
    analogWrite(REDPIN, r);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
  // fade from green to teal
  for (b = 0; b < 256; b++) { 
    analogWrite(BLUEPIN, b);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
  // fade from teal to blue
  for (g = 255; g > 0; g--) { 
    analogWrite(GREENPIN, g);
    fadeSpeed = analogRead(faderPin);
    delay(fadeSpeed);
  } 
}
  else {
    analogWrite(GREENPIN, analogRead(gPin)/4);
    analogWrite(BLUEPIN, analogRead(bPin)/4);
    analogWrite(REDPIN, analogRead(rPin)/4);
    delay(300);
 }  
}

If someone has something to suggest feel free to write :slight_smile:

7

I'll post the code for RGB color chooser

Now that you have found the answer how about posting that code correctly using code tags. Read the how to use the forum pages sticky.
Then modify your post to get it right.

8

Did you check to see if the value displayed in the serial monitor is decimal and not ascii?
can you change colors with software values instead of analog voltages?

9

Did you check to see if the value displayed in the serial monitor is decimal and not ascii?

That makes no sense at all.

10

Grumpy_Mike:

I'll post the code for RGB color chooser

Now that you have found the answer how about posting that code correctly using code tags. Read the how to use the forum pages sticky.
Then modify your post to get it right.

Sorry for the missing code tag,
Hope you enjoy!

11

It appears that you're trying to use pin 3 as both output (BLUEPIN) and input (gpin). If this is true, I wouldn't expect it to work right.