Arduino with NeoPixel Optocouplers Controlling Many Relays

1/*
2  This code for controlling multiple Relais or other actuators from  a single Arduino output pin, has been developed and produced by Pierre Pennings  (December 2018)
3  This solution can be used for typical situations where the  amount of available Arduino output pins is insufficient and more actuators such  as Relais need to be controlled in parallel
4  The principle of operation is based  on using a strip of a number of Neopixels (SMD5050 LEDs with WS2812B controller  chips)
5  Every pixel is put together with an LDR (Light Dependent Resistor),  thus creating a DIY Optocoupler
6  Every individual LED is addressed from one  and the same ARDUINO output pin and the LDR (in series with a 27kOhm resistor),  is connected to a 5V Relais
7  In this way many Neopixel/LDR combinations can  be controlled from 1 Arduino output PIN using the Adafruit Neopixel library.
8  
9  For this Project, which is part of a bigger plan, an ESP 32 (NodeMCU) is  used, however a normal ARDUINO UNO (or almost any other model) will do the job
10  (of course the settings in the code will need to be adjusted, e.g. due to different  Pin allocations)
11  The ESP 32 device works at 3.3 Volt levels (an on-board 3.3V  voltage regulator), while the LED strip with 5050 leds runs on 5 V
12  The ESP  32 is fed with 5 V power (via the USB port from a 5V adaptor or 5v powerbank)
13  The Neopixel LEDs get the 5V supply directly from the 5 volt pin of the ESP 32  and the Relais used are also 5V types.
14  In this example a LED strip of 10 LED's  is used, for simplicity reasons only 4 optocoupler circuits are made controlling  4 Relais connected to one 230V LEDLamp each.
15  The output pin used is GPIO PIN  21 and the RELAIS are controlled via Pixel numbers 1,2,3,4
16    
17  This code  is licensed under GPL3+ license.
18*/
19
20#include <Adafruit_NeoPixel.h>
21#define  NUM_LEDS  10
22
23
24///////////////////////////////////////////////// initialise  the GPIO pin
25const int RelaisPin = 21;                           // pin 21 sends  control data (0 -3.3 V) to the Relais
26int RelaisNo = 0;                                   //  Variable for the applicable Relais to be controlled
27bool RelaisState = false;
28int  r = 0;
29
30Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, RelaisPin, NEO_RGB  + NEO_KHZ800);
31
32/////////////////////////////////////////////////// the setup  code that follows, will run once after "Power On" or after a RESET
33void setup()  {
34  Serial.begin(115200);
35  
36  pinMode(RelaisPin, OUTPUT);                    //  Initializes the RelaisPin as output
37  strip.begin();                                 //  Initialize all LEDs to "off"
38  
39  for (int t = 0; t < 10 ; t++)
40    {
41    strip.setPixelColor(t, 15, 15, 15);          // After Power On all LEDs of the  strip are tested once
42    strip.show();                                // note  that the order of colors of the WS2812 LED strip is R,G,B 
43    delay (500);
44    strip.setPixelColor(t, 0, 0, 0);             // And back to off
45    }
46}
47
48///////////////////////////////////////////////////  the loop code that follows, will run repeatedly until "Power Off" or a RESET
49void  loop(){
50  
51 for (int r = 1; r < 5 ; r++)                     // switch on  the 4 Relais one after another counting form 1 to 4
52    {
53    delay (500);
54    ControlRelais (r , true);
55    delay(500);
56    ControlRelais (r , false);                                  
57    }
58
59for (int k = 4; k > 0 ; k--)                      // switch on the 4 Relais one after another counting form  4 to 1
60   {
61    delay (500);
62    ControlRelais (k , true);
63    delay(500);
64    ControlRelais (k , false);
65   }                          
66
67for (int  r = 1; r < 5 ; r++)                      // switch on the 4 Relais in a patern
68   {
69    for (int k = 4; k > 0 ; k--)
70    {
71    delay (500);
72    ControlRelais  (r , true);
73    ControlRelais (k , true);
74    delay(500);
75    ControlRelais  (r , false);
76    ControlRelais (k , false);
77    }                                   
78  }
79}
80//////////////////END of LOOP////////////////////////////////////////////////////////////  
81
82
83/////////////////////////////////////////////////// Hereafter follows  the Function for controlling the Relais (called from within the loop)
84
85void  ControlRelais (int RelaisNo, bool RelaisState)  {
86
87    strip.setPixelColor(RelaisNo,  RelaisState*15, RelaisState*15, RelaisState*15);      // turn on/off the LED that  belongs to RelaisNo
88    strip.show();
89    Serial.print(" RelaisNo "); Serial.print(RelaisNo);  Serial.print(" = "); Serial.println(RelaisState);
90    }
91