I try to connect 3 RGB LED to my Arduino Nano ESP32

Projects Programming
1

I try to connect 3 RGB LED (common annode) to my Arduino Nano ESP32 which in theory should work because i only need 3x3 (=9) of the 13 digital pins.

But for some reason the LEDs wont work correctly with my code
i am pretty sure my build is correct, but like always not 100% certain
(sorry for the messy build :,) )

The Code should cycle through all the colors, for all 3 LEDs the same

thanks in advance

PXL_20240414_203348716
PXL_20240414_2033487161920×1446 236 KB

PXL_20240414_203357357
PXL_20240414_2033573571920×1446 304 KB

int r_pin1 = 12;
int g_pin1 = 11;
int b_pin1 = 10;

int r_pin2 = 9;
int g_pin2 = 8;
int b_pin2 = 7;

int r_pin3 = 6;
int g_pin3 = 5;
int b_pin3 = 4;

int r_val1 = 0;
int g_val1 = 255;
int b_val1 = 255;

int r_val2 = 0;
int g_val2 = 255;
int b_val2 = 255;

int r_val3 = 0;
int g_val3 = 255;
int b_val3 = 255;

void setup() {

  pinMode(r_pin1,OUTPUT);
  pinMode(g_pin1,OUTPUT);
  pinMode(b_pin1,OUTPUT);

  pinMode(r_pin2,OUTPUT);
  pinMode(g_pin2,OUTPUT);
  pinMode(b_pin2,OUTPUT);


  pinMode(r_pin3,OUTPUT);
  pinMode(g_pin3,OUTPUT);
  pinMode(b_pin3,OUTPUT);


}

void loop() {

  while (r_val1 != 255)
    {
      analogWrite(r_pin1,r_val1);
      analogWrite(g_pin1,g_val1);

      analogWrite(r_pin2,r_val2);
      analogWrite(g_pin2,g_val2);

      analogWrite(r_pin3,r_val3);
      analogWrite(g_pin3,g_val3);

      r_val1++;
      g_val1--;

      r_val2++;
      g_val2--;

      r_val3++;
      g_val3--;

      delay(10);
    }

      while (g_val1 != 255)
    {
      analogWrite(g_pin1,g_val1);
      analogWrite(b_pin1,b_val1);

      analogWrite(g_pin2,g_val2);
      analogWrite(b_pin2,b_val2);

      analogWrite(g_pin3,g_val3);
      analogWrite(b_pin3,b_val3);

      g_val1++;
      b_val1--;

      g_val2++;
      b_val2--;

      g_val3++;
      b_val3--;

      delay(10);
    }

      while (b_val1 != 255)
    {
      analogWrite(b_pin1,b_val1);
      analogWrite(r_pin1,r_val1);

      analogWrite(b_pin2,b_val2);
      analogWrite(r_pin2,r_val2);

      analogWrite(b_pin3,b_val3);
      analogWrite(r_pin3,r_val3);

      b_val1++;
      r_val1--;

      b_val2++;
      r_val2--;

      b_val3++;
      r_val3--;

      delay(10);
    }
}
2

You are using "analogWrite(x,y); " to turn on the LEDs. Correct?
I don't know the ESP32 nano well, but the ESP32 platform doesn't have
the function "analogWrite(x,y);. The ESP 32 uses its own hardware/software
called LEDC.
See the theory of using LEDC in " esp32_technical_reference_manual "

Chapter 14 page 385

Or use a library for PWM for the ESP32.

PS: I find this information
" Yes, the Arduino Nano has PWM (Pulse Width Modulation) capabilities .

3

analogWrite() has been implemented for the ESP32 for some time. Behind the scenes it uses ledc

It certainly works for me

4

the code works correct as long as I only use one RGB LED but it does not work anymore as soon as I try to use 2 or 3 LEDs

5

What does it mean "it doesn't work anymore as soon as I try to use 2 or 3 LEDs?"
Explain more....

6

Hi, @starkai
Welcome to the forum.

Have you checked how much current you are drawing through each output?

Tech specs

Board Name Arduino® Nano ESP32 with headers
SKU ABX00083
Microcontroller u-blox® NORA-W106 (ESP32-S3)
USB connector USB-C®
Pins Built-in LED Pin 13
Built-in RGB LED pins 14-16
Digital I/O Pins 14
Analog input pins 8
PWM pins 5
External interrupts All digital pins
Connectivity Wi-Fi® u-blox® NORA-W106 (ESP32-S3)
Bluetooth® u-blox® NORA-W106 (ESP32-S3)
Communication UART 2x
I2C 1x, A4 (SDA), A5 (SCL)
SPI D11 (COPI), D12 (CIPO), D13 (SCK). Use any GPIO for Chip Select (CS)
Power I/O Voltage 3.3 V
Input voltage (nominal) 6-21 V
Source Current per I/O Pin 40 mA
Sink Current per I/O Pin 28 mA
Clock speed Processor up to 240 MHz
Memory ROM 384 kB
SRAM 512 kB
External Flash 128 Mbit (16 MB)
Dimensions Width 18 mm
Length 45 mm

Check the current output limits of the Nano ESP32.

Tom.. :smiley: :+1: :coffee: :australia:

7

This is the code I used for only one RGB LED

on this code I added the other 2 LEDs
(e.g. r_pin1, r_pin2, r_pin3 and r_val1++, etc...)

int r_pin = 12;
int g_pin = 11;
int b_pin = 10;

int r_val = 0;
int g_val = 255;
int b_val = 255;

void setup() {

  pinMode(r_pin,OUTPUT);
  pinMode(g_pin,OUTPUT);
  pinMode(b_pin,OUTPUT);

}

void loop() {

  while (r_val != 255)
    {
      analogWrite(r_pin,r_val);
      analogWrite(g_pin,g_val);

      r_val++;
      g_val--;

     delay(10);
    }

      while (g_val != 255)
    {
      analogWrite(g_pin,g_val);
      analogWrite(b_pin,b_val);

      g_val++;
      b_val--;

      delay(10);
    }

      while (b_val != 255)
    {
      analogWrite(b_pin,b_val);
      analogWrite(r_pin,r_val);

      b_val++;
      r_val--;

      delay(10);
    }
}
8

my RGB LEDs are labeled 20mA

"Each GPIO pin is rated at 40mA for a ESP32"
"250mA is the ESP 32s max current draw"

if I understand the Tech Specs there should be no problem with connecting 3 RGB LEDs

9

Hi,
What if you write some simple code to just turn some of the LEDS ON and OFF, using digitalWrite?
Test your hardware then work towards analogWrite in stages.

Tom... :smiley: :smiley: :+1: :coffee: :australia:

10

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