Motivation
Philosophy
Wemos LOLIN D1 Mini
Features
Web Interface
Device Interface
Power Relay
Schematic
Web Services
Arduino Libraries Used
Assembly
Epilogue

Published July 26, 2022 © LGPL

Sunset Switch - Overkill

Over engineered sunset switch for exterior LED lights. Gets time of day and sunset time updates from web. Ode to the Wemos D1 Mini..

IntermediateFull instructions provided4 hours497

Things used in this project

Hardware components

Adafruit MAX9814

Arduino Compatible 5V Relay Board

Wemos LOLIN D1 mini

Linear Regulator (7805)

ElectroPeak 0.96" OLED 64x128 Display Module

Software apps and online services

Arduino IDE

Story

Motivation

We eventually got tired of the generic solar recharged lawn lights that light the edge of our driveway at night (they all eventually fail) and replaced them with a string of mains powered LED lights.

Now we needed a sunset driven switch to automatically turn them on for a few hours after sunset every day. Time for some Wemos D1 Mini love and some overkill.

Reliable Driveway Lighting

Philosophy

If it worked yesterday and you didn't touch it, then it should work today. Forever. No updates. No "have you tried turning the power on and off again".

Also, when building something, first try using the parts on hand before buying new bits and pieces.

Wemos LOLIN D1 Mini

In case it wasn't obvious, I like these microcontroller boards a lot. I've tried to migrate to newer shinier ones but I just keep coming back to this old favorite for one reason: it just works.

Key features:

small enough form factor
powerful enough with enough storage
relatively cheap
always trivial to program from the Arduino IDE
old and mature enough to have good drivers for 3rd party peripherals
reliable built-in WiFi with good client and server drivers

Wemos LOLIN D1 mini

For quick reference, this is the best pinout diagram I've found for it from Renzi Mischianti:

Wemos LOLIN D1 mini pinout

Features

Here's what I want the device to be capable of:

Lights on at sunset for a configurable amount of time
Override mode to easily turn them on at other times (like 3am for example)
Automatically keep time (none of this flashing 12:00 rubbish)
Automatically adjust sunset time through the year
Simple browser web interface to use the override, inspect and configure
Tap to display IP address (for when it inevitably gets re-assigned in future)

I won't give paint-by-numbers instructions. Instead, I'll just supply a full schematic and the source of my Arduino sketch along with some notes on the implementation each of the features. I suspect nobody will build this exact device but may well benefit from copying one or more of the features for some other purpose.

Web Interface

I take advantage of the built-in Wifi and web functionality of the D1 mini. I've used both the server and the client parts in other projects so I already had code to get past most of the common gotchas. I leave the serial output in the live version so I can easily hook up a USB cable and diagnose initialization when it fails in future.

The image below is a screenshot showing what my simple web user interface looks like:

Web interface functionality

I use ESP8266WebServer for the web server and this documentation is actually pretty good. My use of a <button> tag and a <meta> refresh is a quick and dirty way of gettings some web buttons to work.

Device Interface

The only reason to have an OLED display on the device is so that we can easily know which IP address has been allocated to it so we can actually find the web server in the browser. But, once you've got a display, you may as well include other diagnostic information: I just replicated the same stuff as the web UI:

However, OLED displays do burn out over time (~4-5 years) so it makes sense not to leave them "always on". For this reason I used a microphone sensor as a switch to turn the OLED on for 15 seconds. The enclosure makes for a convenient sound box so you can simply tap on the box with a knuckle to turn on the OLED. I have a project about using the MAX9814 as an Audio Switch that describes this trick in more detail.

MAX9814 Microphone

Power Relay

Originally I thought I could simply switch the 12V supply using a MOSFET switch like the VO12642T since it can handle 2A and isolates this current from the delicate electronics. However, after measuring the current draw of the exterior LED lights at 1.7A it made me change to something with more capacity to not be that close to the 2A limit. I had a 10A relay breakout board on hand so I used that instead.

10A Relay - no magic blue smoke!

Schematic

Add a 7805 regulator to get us a 5V supply from the 12V LED driver and that's pretty much the circuit done. I added a 1A fuse for the delicate electronics (because I'm getting older and wiser). Another important thing to remember is that not all the delicate stuff is 5V: both the OLED and the MAX9814 have 3.3V logic levels and are small enough to be powered using the 3.3V supply from the D1 mini.

Sunset Switch Schematic

Web Services

I keep time using Arduino millis() which is not known to be terribly accurate and will wrap around every ~50 days. My solution is to reset the time once every 24 hours using worldtimeapi.org, a free public web service.The API for me, being in New Zealand, is:http://worldtimeapi.org/api/timezone/pacific/auckland

Note:http://, not https://

I use a second free public web service to get today's sunset time at my location (yes, I could just do the math, but I'm lazy and I'm already hitting the web). At the same time I call to update the time, I also call sunrise-sunset.org to get today's sunset time for my location. Use Google maps to get your longitude and latitude. The API call will be something like:http://api.sunrise-sunset.org/json?lat=-YY.YYYY&lng=XX.XXXX

Note:http://, not https://

These web service calls are made using the reliable WiFiClient and this documentation is pretty good.

Both of these web services return the response as JSON. I've found that this JSON library is great for parsing these responses.

So, as a reminder, three things you need to customize in my code according to your details:

STASSID and STAPSK - ssid and password for your own home WiFi
The URL for the web call to worldtimeapi.org based on your time zone
The URL for the web call to sunrise-sunset.org based on your location

Arduino Libraries Used

Screenshots from Arduino IDE 2.x just in case you get stuck trying to find the correct drivers:

https://arduinojson.org

https://github.com/adafruit/Adafruit_SSD1306

https://arduino.esp8266.com/stable/package_esp8266com_index.json

This last one is probably what you'd install anyway to use the Wemos LOLIN D1 mini and I believe that includes the web server and client libraries.

Assembly

I'm installing the microcontroller circuitry inside the same enclosure that houses the AC mains to 12V DC power supply for the LED lights. I've made the mistake on previous projects of making things too tight and too small. I've also made the mistake of making things too hard to disassemble and take out of the field and back to the workbench.

Why not use wood?

Using a cutting blade of my Dremel made it easy to take a 4mm thick sheet of "craft" plywood and get it perfectly sized for a squeeze fit: sits snuggly in the enclosure but can still be easily removed.

Major components are screwed to the plywood. The USB port on the microcontroller is still accessible. The 3 connections to the 12V power and the LEDs are easily disconnected and reconnected.

Epilogue

My "philosophy" mentioned at the start is aspirational: the design needs to evolve into this ideal state.

So, when I discover what's wrong with this system in future, I will fix it and update this project. Stuff just needs to work reliably.

Code

Sunset Switch Arduino Sketch

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>


#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>

#include <ArduinoJson.h>

// Comment this out once you've finished debugging
#define SERIAL_MONITOR

#define STASSID "##########"
#define STAPSK  "##########"

#define SWITCH_PIN 0 // D3 on Wemos D1 Mini
#define KNOCK_PIN 17 // A0 on Wemos D1 Mini



// Start with a low value and test what works in your environment via the Serial Monitor
const int threshold = 750; 
int inputFromMAX9814 = 0;

const int secondsOLEDOn = 15;     // how long to keep the OLED visible after it is turned on
const int secondsOLEDRefresh = 1; // refresh the OLED (when visible) every <n> seconds

const unsigned long twentyFourHours = 24*60*60;
bool activeOLED = true;
unsigned long timeOLEDActivated = 0;
unsigned long timeLastScreenUpdate = 0;
unsigned long timeLastWebCheck = 0;
unsigned long timeWebBase = 0;
unsigned long sunsetWebBase = 0;
long onAfterSunset = (3*60 + 30) * 60; // 3.5 hours
long onOverride = 0;

// ########## OLED code ##########

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void printOLED(int iColumn, int iRow, const char * text)
{
  // https://en.wikipedia.org/wiki/Code_page_437
  int x = iColumn * 4;
  int y = iRow * 9;
  display.setCursor(x, y); // top left is 0,0
  int length = strlen(text);
  for
  (int i=0; i<length; i++) 
  {
    display.write(text[i]);
  }
  display.display();
}

void clearScreen()
{
  display.clearDisplay();
}

String GetLocalIP();

void initOLED()
{
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) 
  { 
#ifdef SERIAL_MONITOR
    Serial.println(F("SSD1306 allocation failed"));
#endif
    for(;;); // Don't proceed, loop forever
  }
  else
  {
    display.clearDisplay();
    display.setTextSize(1);      // Normal 1:1 pixel scale
    display.setTextColor(WHITE); // Draw white text
    display.setCursor(0, 0);     // Start at top-left corner
    display.cp437(true);         // Use full 256 char 'Code Page 437' font (https://en.wikipedia.org/wiki/Code_page_437)
    display.display();
    printOLED(0, 0, "Initializing:");
    printOLED(2, 1, "OLED");
  }
}

// ########## end of OLED code ##########

// ########## Web Server code ##########

const int httpPort = 80;
ESP8266WebServer server(httpPort);

bool ConnectToWifi(const char *  ssid, const char *  password)
{
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
#ifdef SERIAL_MONITOR  
  Serial.println("");
#endif
  int count = 0;
  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
#ifdef SERIAL_MONITOR    
    Serial.print(".");
#endif    
    count++;
    if (count > 20)
    {
      return false;
    }
  }
  return true;
}

void SendResponse(int httpCode, String message)
{
  server.send(httpCode, "text/plain", message);
}
bool HasArg(String name)
{
  return server.hasArg(name);
}
String GetArg(String name)
{
  return server.arg(name);
}
String GetLocalIP()
{
  String localIP = WiFi.localIP().toString();
  return localIP;
}

void handleNotFound() 
{
  String message = "File Not Found\n\n";
  message += "URI: ";
  message += server.uri();
  message += "\n";
  SendResponse(404, message);
}
void handleRoot() 
{
  String message;
  unsigned long timeNow = millis() / 1000;
  
  
  unsigned long secondsSinceLastCheck = timeNow - timeLastWebCheck;
  unsigned long currentTime = timeWebBase + secondsSinceLastCheck;
  while (currentTime > twentyFourHours)
  {
    currentTime = currentTime - twentyFourHours;
  }
  
  bool redirect = false;
  if (server.hasArg("increase"))
  {
    onAfterSunset += 30 * 60;
    redirect = true;
  }
  if (server.hasArg("decrease"))
  {
    onAfterSunset -= 30 * 60;
    if (onAfterSunset < 0)
    {
      onAfterSunset = 0;
    }
    redirect = true;
  }
  if (server.hasArg("override"))
  {
    onOverride += 5 * 60;
    redirect = true;
  }
  if (redirect)
  {
    message += "<html>";
    message += "<head>";
    message += "  <title>HTML Meta Tag</title>";
    message += "  <meta http-equiv=\"refresh\" content=\"0; url=http://" + GetLocalIP() + "\" />";
    message += "<style>";
    message += "body {\n";
    message += "  background-color: #005C5F;\n";
    message += "}\n";
    message += "</style>";
    message += "</head>";
    message += "<body>";
    message += "  <p>Reloading</p>";
    message += "</body>";
    message += "</html>";
    server.send(200, "text/html", message);
    return;
  }
  
  
  
  message += "<html>";
  message += "<head>";
  message += "<style>";
  message += "body {\n";
  message += "  background-color: #005C5F;\n";
  message += "}\n";
  message += "h3 {\n";
  message += "  font-weight: 600;\n";
  message += "  font-size: 30pt;\n";
  message += "  color: #FFFFFF;\n";
  message += "  font-family: sans-serif;";
  message += "}\n";
  message += "p, body {\n";
  message += "  font-weight: 600;\n";
  message += "  font-size: 18pt;\n";
  message += "  color: #FFFFFF;\n";
  message += "  font-family: sans-serif;";
  message += "}\n";
  message += "</style>\n";
  message += "</head>";
  message += "<body>";
  message += "<h3>Sunset Switch</h3>";
  message += "<table>";
  message += "<tr>";
  message += "<td>";
  message += "Time:";
  message += "</td>";
  message += "<td>";

  int hours = currentTime / (60*60);
  int minutes = (currentTime / 60) % 60;
  int seconds = currentTime % 60;
  char text[128];
  sprintf(text, "%02d:%02d:%02d", hours, minutes, seconds);

  message += text;
  message += "</td>";
  message += "</tr>";
  message += "<tr>";
  message += "<td>";
  message += "Sunset:";
  message += "</td>";
  message += "<td>";

  hours = sunsetWebBase / (60*60);
  minutes = (sunsetWebBase / 60) % 60;
  seconds = sunsetWebBase % 60;
  sprintf(text, "%02d:%02d:%02d", hours, minutes, seconds);
  
  message += text;
  message += "</td>";
  message += "</tr>";
  message += "<tr>";
  message += "<td>";
  message += "&nbsp;";
  message += "</td>";
  message += "</tr>";
  message += "<tr>";
  message += "<td>";
  message += "On time:";
  message += "</td>";
  message += "<td>";

  hours = onAfterSunset / (60*60);
  minutes = (onAfterSunset / 60) % 60;
  sprintf(text, "+%02d:%02d:00", hours, minutes);
  
  message += text;
  message += "<td>";
  message += "<button onclick=\"window.location.href='/?decrease=1';\">";
  message += "Decrease";
  message += "</button>";
  message += "</td>";
  message += "<td>";
  message += "<button onclick=\"window.location.href='/?increase=1';\">";
  message += "Increase";
  message += "</button>";
  message += "</td>";
  message += "</td>";
  message += "</tr>";

  message += "<tr>";
  message += "<td>";
  message += "&nbsp;";
  message += "</td>";
  message += "</tr>";
  message += "<tr>";
  message += "<td>";
  message += "Override:";
  message += "</td>";
  message += "<td>";

  hours = onOverride / (60*60);
  minutes = (onOverride / 60) % 60;
  seconds = onOverride % 60;
  sprintf(text, "+%02d:%02d:%02d", hours, minutes, seconds);
  
  message += text;
  message += "<td>";
  message += "&nbsp;";
  message += "</td>";
  message += "<td>";
  message += "<button onclick=\"window.location.href='/?override=1';\">";
  message += "Increase";
  message += "</button>";
  message += "</td>";
  message += "</td>";
  message += "</tr>";
  message += "</table>";
  message += "<p>";

  message += "</p>";
  message += "</body>";
  message += "</html>";
  server.send(200, "text/html", message);
}

void initServer()
{
  String ssid = STASSID;
  if (!ConnectToWifi(STASSID, STAPSK))
  {
#ifdef SERIAL_MONITOR
    Serial.println("");
    Serial.print("Failed to Connect to WiFi");
#endif
    delay(5000);
    return;
  }
#ifdef SERIAL_MONITOR      
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
#endif  
  String localIP = GetLocalIP();
#ifdef SERIAL_MONITOR      
  Serial.println(localIP);
#endif

  if (MDNS.begin("esp8266")) 
  {
#ifdef SERIAL_MONITOR          
    Serial.println("MDNS responder started");
#endif    
  }

  printOLED(2, 2, "WebServer");

  printOLED(4, 4, localIP.c_str());

  //server.on("/hopper/poke", handlePoke);
  server.on("/", handleRoot);
  server.onNotFound(handleNotFound);

  server.begin();
#ifdef SERIAL_MONITOR  
  Serial.println("HTTP server started");
  Serial.println("");
#endif
  timeOLEDActivated = millis() / 1000;
  timeLastScreenUpdate = timeOLEDActivated;
}

// ########## end of Web Server code ##########

void showOLED(bool onOff)
{
  if (onOff)
  {
    display.ssd1306_command(SSD1306_DISPLAYON);
    timeOLEDActivated = millis() / 1000;
  }
  else
  {
    display.ssd1306_command(SSD1306_DISPLAYOFF);
  }
}


void webCheck()
{
  int timeZoneHours = 0;
  WiFiClient timeClient;
  if (timeClient.connect("worldtimeapi.org",80))
  {
#ifdef SERIAL_MONITOR  
    Serial.println("Connected to worldtimeapi.org");
#endif
    
    timeClient.println("GET /api/timezone/pacific/auckland HTTP/1.1");
    timeClient.println("Host: worldtimeapi.org");
    timeClient.println("Connection: close");
    timeClient.println();
    unsigned long timeout = millis();
    while (timeClient.available() == 0) 
    {
      if (millis() - timeout > 30000)
      { 
#ifdef SERIAL_MONITOR          
        Serial.println("worldtimeapi.org Timeout !");
#endif        
        timeClient.stop(); 
        delay(5000);
        return; 
      } 
    } 
    String timeJSON;
    while (timeClient.available())
    { 
      char c = timeClient.read();
      timeJSON += c;
      delay(1);
    }
    timeClient.stop();

#ifdef SERIAL_MONITOR          
    //Serial.println(timeJSON);
#endif     

    int i = timeJSON.indexOf('{');
    if (i != -1)
    {
      timeJSON = timeJSON.substring(i);

      DynamicJsonDocument jsonDoc(2048);
      deserializeJson(jsonDoc, timeJSON);

      String dateTime = jsonDoc["datetime"];
      String uctDateTime = jsonDoc["utc_datetime"];

      i = dateTime.indexOf('+');
      String timeZone = dateTime.substring(i+1, i+3);
      i = dateTime.indexOf('T');
      dateTime = dateTime.substring(i+1, i+9);
      i = uctDateTime.indexOf('T');
      uctDateTime = uctDateTime.substring(i+1, i+9);
#ifdef SERIAL_MONITOR          
      Serial.println(dateTime);
      Serial.println(uctDateTime);
      Serial.println(timeZone);
#endif     
      int hours = dateTime.substring(0,2).toInt();
      int minutes = dateTime.substring(3,5).toInt();
      int seconds = dateTime.substring(6,8).toInt();

      timeZoneHours = timeZone.substring(0,2).toInt();
      timeWebBase = hours * 60 * 60 + minutes * 60 + seconds;
      timeLastWebCheck = millis() / 1000;

      showOLED(true);
    }
    else
    {
#ifdef SERIAL_MONITOR  
      Serial.println("{ not found in worldtimeapi.org response");
#endif      
      delay(5000);
    }
  }
  else
  {
#ifdef SERIAL_MONITOR  
    Serial.println("Failed to connect to worldtimeapi.org");
#endif    
    delay(5000);
  }

  WiFiClient sunsetClient;
  if (sunsetClient.connect("api.sunrise-sunset.org",80))
  {
#ifdef SERIAL_MONITOR  
    Serial.println("Connected to api.sunrise-sunset.org");
#endif
    
    sunsetClient.println("GET /json?lat=YY.YYYY&lng=XXX.XXXX&formatted=0 HTTP/1.1");
    sunsetClient.println("Host: api.sunrise-sunset.org");
    sunsetClient.println("Connection: close");
    sunsetClient.println();

    unsigned long timeout = millis();
    while (sunsetClient.available() == 0) 
    {
      if (millis() - timeout > 30000)
      { 
#ifdef SERIAL_MONITOR          
        Serial.println("api.sunrise-sunset.org Timeout !");
#endif        
        sunsetClient.stop(); 
        delay(5000);
        return; 
      } 
    } 

    String timeJSON;
    while (sunsetClient.available())
    { 
      char c = sunsetClient.read();
      timeJSON += c;
      delay(1);
    }
    sunsetClient.stop();

#ifdef SERIAL_MONITOR          
    //Serial.println(timeJSON);
#endif     

    int i = timeJSON.indexOf('{');
    if (i != -1)
    {
      timeJSON = timeJSON.substring(i);

      DynamicJsonDocument jsonDoc(2048);
      deserializeJson(jsonDoc, timeJSON);

      String sunsetTime = jsonDoc["results"]["sunset"];

      i = sunsetTime.indexOf('T');
      sunsetTime = sunsetTime.substring(i+1, i+9);
#ifdef SERIAL_MONITOR          
      Serial.println(sunsetTime);
#endif     
      int hours = sunsetTime.substring(0,2).toInt() + timeZoneHours;
      int minutes = sunsetTime.substring(3,5).toInt();
      int seconds = sunsetTime.substring(6,8).toInt();
      sunsetWebBase = hours * 60 * 60 + minutes * 60 + seconds;

      showOLED(true);
    }
    else
    {
#ifdef SERIAL_MONITOR  
      Serial.println("{ not found in api.sunrise-sunset.org response");
#endif      
      delay(5000);
    }
  }
  else
  {
#ifdef SERIAL_MONITOR  
    Serial.println("Failed to connect to api.sunrise-sunset.org");
#endif    
    delay(5000);
  }
}

void updateDisplay()
{
  unsigned long timeNow = millis() / 1000;

  clearScreen();
  char text[128];
  //sprintf(text, "Out:%d", inputFromMAX9814);
  //printOLED(0, 0, text);

  unsigned long secondsSinceLastCheck = timeNow - timeLastWebCheck;
  unsigned long currentTime = timeWebBase + secondsSinceLastCheck;
  while (currentTime > twentyFourHours)
  {
    currentTime = currentTime - twentyFourHours;
  }

  int hours = currentTime / (60*60);
  int minutes = (currentTime / 60) % 60;
  int seconds = currentTime % 60;
  
  printOLED(0, 0, "Time:");
  sprintf(text, "%02d:%02d:%02d", hours, minutes, seconds);
  printOLED(16, 0, text);

  hours = sunsetWebBase / (60*60);
  minutes = (sunsetWebBase / 60) % 60;
  seconds = sunsetWebBase % 60;
  
  printOLED(0, 1, "Sunset:");
  sprintf(text, "%02d:%02d:%02d", hours, minutes, seconds);
  printOLED(16, 1, text);

  hours = onAfterSunset / (60*60);
  minutes = (onAfterSunset / 60) % 60;
  
  printOLED(0, 2, "On time:");
  sprintf(text, "+%02d:%02d:00", hours, minutes);
  printOLED(15, 2, text);

  hours = onOverride / (60*60);
  minutes = (onOverride / 60) % 60;
  seconds = onOverride % 60;
  
  printOLED(0, 3, "Override:");
  sprintf(text, "+%02d:%02d:%02d", hours, minutes, seconds);
  printOLED(15, 3, text);

  //sprintf(text, "Seconds left:%d", (int)(secondsOLEDOn-(timeNow - timeOLEDActivated)));
  //printOLED(0, 4, text);

  String localIP = GetLocalIP();
  printOLED(6, 5, localIP.c_str());
  timeLastScreenUpdate = timeNow;
}

void setup() 
{
  pinMode(SWITCH_PIN, OUTPUT);
  digitalWrite(SWITCH_PIN, LOW); // start with lights off
#ifdef SERIAL_MONITOR  
  Serial.begin(115200); 
#endif
  initOLED();
  initServer();
  delay(1000);
  webCheck();
  updateDisplay();
}



int overrideLaps = 0;

void loop() 
{
  unsigned long timeNow = millis() / 1000;
  server.handleClient();

  unsigned long secondsSinceLastWebCheck = timeNow - timeLastWebCheck;
  if (secondsSinceLastWebCheck > 24*60*60)
  {
    webCheck();
  }

  // read the sensor and store it in the variable sensorReading:
  inputFromMAX9814 = analogRead(KNOCK_PIN);

  if (activeOLED && (timeNow - timeOLEDActivated > secondsOLEDOn))
  {
    activeOLED = false;
    showOLED(activeOLED);
    updateDisplay();
  }
  else if (inputFromMAX9814 >= threshold) 
  {
#ifdef SERIAL_MONITOR      
    Serial.println(inputFromMAX9814);
#endif
    activeOLED = true;
    showOLED(activeOLED);
    updateDisplay();
    
    // this delay ensures that we only trigger our switch once per second ("debouncing")
    delay(1000);
  }
  else if (timeLastScreenUpdate - timeNow > secondsOLEDRefresh)
  {
    updateDisplay();
  }
  // All of these are in seconds
  // - timeLastWebCheck : millis()/1000 when we last updated timeWebBase and sunsetWebBase
  // - timeWebBase   : current time in seconds the last time we checked
  // - sunsetWebBase : sunset time in seconds the last time we checked
  // - onAfterSunset : delta to keep lights on in seconds
  // - secondsSinceLastWebCheck : millis()/100 since last time we checked

  bool switchOn = false;
  unsigned long currentTime = timeWebBase + secondsSinceLastWebCheck;
  while (currentTime > twentyFourHours)
  {
    currentTime = currentTime - twentyFourHours;
  }
  unsigned long offTime = sunsetWebBase + onAfterSunset;
  if ((currentTime > sunsetWebBase) && (currentTime < offTime))
  {
    switchOn = true;
  }
  else if (onOverride > 0)
  {
    if (overrideLaps <= 0)
    {
      onOverride--;
      overrideLaps = 100;
    }
    else
    {
      overrideLaps--;
    }
    switchOn = (onOverride > 0);
  }
  digitalWrite(SWITCH_PIN, switchOn ? HIGH : LOW);

  // If the endless loop is too tight, we spin our wheels in the call to 'server.handleClient()'
  // If we spend too much time in each loop, then the audio switch won't work (which is why we have overrideLaps)
  delay(10); 
}

Credits

Michael Cartwright

21 projects • 13 followers

Sunset Switch - Overkill