Controlling RGBW 5050 LED Strip with ESP32

[MechApe]

Hello,

First ever GIT post! Firstly, thank you so much for putting this library together. I am a noob programmer and I can (almost!) get this code working. So hats off to everyone involved! I've been able to get some basic tests working with LEDs, an ESP32 and my Echo Dot...great! Now I would like to connect an RDGW 5050 LED strip.

Am I correct in thinking that I should use an GPIO pin for each of the R, G, B and W lines wired through a transistor? Then in my code I should declare the pin: const int redPin = 2;

then
void setup()
...
pinMode(redPin, OUTPUT);

Now, this is where I get a bit stuck. In the callback function, I can see that I can do something like the following:
analogWrite(redPin, d->getR())

But how does this relate to the brightness or d->getValue(). And will this also work the the W line?

Any help would be very much appreciated!

[barneyz]

Hi, the ESP32 has a different way for pwm output:

only example code copied from my project

// RGBW-Handling **************************
const int channel_r = 0;	// channels for pins/ports
const int channel_g = 1;
const int channel_b = 2;
const int channel_w = 3;

// RGBW-Handling **************************
const uint8_t port_LED_r = 23; // example ESP32 output pwm pins/ports for RGBW
const uint8_t port_LED_g = 19;
const uint8_t port_LED_b = 21;
const uint8_t port_LED_w = 22;

setup()
{
	// RGBW-Handling **************************
	// Strip RGBWW ports init
//channel 0-15 resolution 1-16bits freq limits depend on resolution
//double      ledcSetup(uint8_t channel, double freq, uint8_t resolution_bits);
//void        ledcWrite(uint8_t channel, uint32_t duty);

	const int freq = 5000;		// PWM frequency
	const int resolution = 8;	        // 8 Bit resolution
 	
	ledcSetup(channel_r, freq, resolution);
	ledcSetup(channel_g, freq, resolution);
	ledcSetup(channel_b, freq, resolution);
	ledcSetup(channel_w, freq, resolution);

	ledcAttachPin(port_LED_r, channel_r);
	ledcAttachPin(port_LED_g, channel_g);
	ledcAttachPin(port_LED_b, channel_b);
	ledcAttachPin(port_LED_w, channel_w);

	ledcWrite(channel_r, 0);  // all off
	ledcWrite(channel_g, 0);
	ledcWrite(channel_b, 0);
	ledcWrite(channel_w, 0);
}

void colorcallback(uint8_t brightness, uint32_t rgb)
{
  uint16_t r,g,b;
  int32_t br_r, br_g, br_b;					// new values RGB with brightness

  //example for calculating one color 
  // RGB LED color 0-255
  r = alexadevice_rgb->getR();    // red color
  br_r = (r * (uint16_t)brightness ) / 255;	 // 8 Bit value

  ... blue
  ... green

  ledcWrite(channel_r, br_r);			// write final colors to strip
  ledcWrite(channel_g, br_g);
  ledcWrite(channel_b, br_b);
}


void whitecallback(uint8_t brightness)
{
  ledcWrite(channel_w, brightness);		// white
}

For all my lightning-projects with RGBW-Strips i always implemented two espalaexadevices, on for color and one for white.

And i made a fade function (not in the example above), so the callback function only set new color or white value and a fade flag and the color/brightness change is in an ISR. The ISR fades in 2 seconds from old to the new one color or brightness (can also be off).

The hardware, i always use ULN2003 chips with pullups on outputs 1,8kohm to 12Volt followed by an RGBW-Amplifier.

Switching with a transistor is also possible.

[MechApe]

Thank you @barneyz ! I will take a look this evening. 👍

Am I correct in thinking that you separated out the W from the RGB since you cannot get the W component from the EspalexaDeviceType::extendedcolor device type?

[barneyz]

I separated WW(warm white) and RGB in my RGBWW-strips because of more options like pastel colors or double the brightness if needed . When you have only one device you never can switch both WW and RGB.

The ULN2003 or ULN 2803 can direct drive 5V relais, so i have separate 5V (ESP32) and 12V supplys, the ESP can switch the 12V supply of for less power consumption when no LEDS are on.