Mario DArrisso
Published © GPL3+

Smart Irrigation system using an IO expander

How to use an ESP8266 12-E with an IO expander to create a smart wifi irrigation system controller with a web interface

AdvancedFull instructions provided6 hours515
Smart Irrigation system using an IO expander

Things used in this project

Hardware components

NodeMCU ESP8266 Breakout Board
NodeMCU ESP8266 Breakout Board
×1
PCF8575 IO Expander Board Module I2C to 16IO
×1
8-Channel Relay Module
×1
AC/DC buck converter
×1

Story

Read more

Schematics

Schematic for irrigation system

Sorry for the hand drawing. But it would have taken me way too long if done with software... The 'NO' stands for 'Normally Open'

Code

Untitled file

C/C++
/*  Irrigation system
    Version 1.0

  PCF8575N & PCF8574N is 'reverse' logic in as much it SINKS current.
	so HIGH is OFF and LOW is ON.
	Turn OFF all pins by sending a high byte (1 bit per byte)

// OFF        B11111111,B11111111     // OFF for all 16 IO
// ON         B00000000,B00000000     // ON  for all 16 IO

*/

#include <Arduino.h>
#include <NodeMCU_Pinouts.h>
#include <Wire.h>
#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <time.h>
#include <EEPROM.h>

const char* ssid     = "MySSID";
const char* password = "Password";

String host_name = "PoC";
int timezone = (4 * 60 * 60);               // For UTC -5.00 : -5 * 60 * 60 : -18000
const int EPOCH_1_1_2019 = 1546300800;      // For NTP - 1546300800 =  01/01/2019 @ 12:00am (UTC)
const char* ntpServer = "pool.ntp.org";
time_t now;

static unsigned long lastGetTimeClock;      // Counter for updating UTC time after a delay
static const int ZoneOthers = 0xFF ;
const long zoneTimerInterval = 350000UL;    // timer ~ 5min
unsigned long zoneTimerPrevious = 0;        // timer will store last time timer was updated
int zoneTimerState = 0;                     // timer
int EEaddress = 0;                          // EEprom address

bool flag_isAutoDay;
bool flag_isAutoDay_Executed;
bool flag_isAutoDay_notExecute = true;       // Reset the flag autoIrrigation to 'Execute' when odd day is coming
bool flag_isAutoHourReady = false;

String thisTime = "none";
String autoLastrunTime = "";

bool autoPilot = true;
int  autoPilotSetZone;
int  allZones_counter;
bool allZones_flag = false;
bool allZonesTimer_flag = false;

ESP8266WebServer server(80);

int address = 0x20; //0100000 (7bit)            //address is |0100|A0|A1|A2|

static const uint8_t ku8TWISuccess    = 0;       //I2C/TWI success (transaction was successful).
static const uint8_t ku8TWIDeviceNACK = 2;       //I2C/TWI device not present (address sent, NACK received).
static const uint8_t ku8TWIDataNACK   = 3;       //I2C/TWI data not received (data sent, NACK received).
static const uint8_t ku8TWIError      = 4;       //I2C/TWI other error.

static const uint8_t Zone_1 = 0b11111110 ;
static const uint8_t Zone_2 = 0b11111101 ;
static const uint8_t Zone_3 = 0b11111011 ;
static const uint8_t Zone_4 = 0b11110111 ;
static const uint8_t Zone_5 = 0b11101111 ;
static const uint8_t Zone_6 = 0b11011111 ;
static const uint8_t Zone_7 = 0b10111111 ;
static const uint8_t Zone_8 = 0b01111111 ;
static const uint8_t Zone_off = 0b11111111 ;

String htmlpage = "";          // Web page 

// ================================= Subroutines 

void Relay_off()
{
	Wire.beginTransmission(address);
	Wire.write(lowByte(Zone_off));
	Wire.write(lowByte(Zone_off));
	Wire.endTransmission();
  
  zoneTimerState = 0;                  // disable the 'zoneTimerState - if condition' in the 'loop' function
	delay(2500);
}

void Execute_Zone(uint8_t zone)
{
  Wire.beginTransmission(address);     // Set the Relay for the Zone
	Wire.write(lowByte(zone));
	Wire.write(lowByte(zone));
	Wire.endTransmission();
  
  zoneTimerState = 1;                  // 0 = off, 1 = ON // Enable the 'zoneTimerState' if condition in the 'loop' function
  zoneTimerPrevious = millis();        // start the countdown using millis to compare with 'ZoneTimerNow' in 'loop' function
}

void autoMode_onORoff(bool val)
{
  if(val)
  {
    autoPilot = true;
  }
  else
  {
    autoPilot = false;
  }
  
  EEaddress = 0;                                  // EEprom address of autoPilotSetting
  EEPROM.write(EEaddress, autoPilot);             // Write to memory
  EEPROM.commit();                                // written to flash                   
  
}

void webpageMain()
{
  htmlpage += "<!DOCTYPE html>";
  htmlpage += "<head><title>IoT Irrigation</title>";
  htmlpage += "<style>";
  htmlpage += "#header  {background-color:blue;      font-family:Tahoma,Verdana,Serif,sans-serif; width:1024px; padding:5px; color:white; text-align:center; }";
  htmlpage += "#section {background-color:#C2DEFF;   font-family:Tahoma,Verdana,Serif,sans-serif; width:1024px; padding:5px; color:blue;  font-size:12px;}";
  htmlpage += "#footer  {background-color:steelblue; font-family:Tahoma,Verdana,Serif,sans-serif; width:1024px; padding:5px; color:white; font-size:9px; clear:both;}";
  htmlpage += "</style></head>";
  htmlpage += "<script type=\"text/javascript\"> function reloadPage() {location.reload(true)} </script>";
  htmlpage += "<body>";
  htmlpage += "<div id=\"header\"><h1>Irrigation System 1.0</h1></div>";
  htmlpage += "<div id=\"section\"><h3>";
  htmlpage += "<form action=\"/\" method=\"POST\">";
  htmlpage += "<center>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone1\">   Zone-1";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone2\">   Zone-2";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone3\">   Zone-3";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone4\">   Zone-4";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone5\">   Zone-5";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone6\">   Zone-6";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone7\">   Zone-7";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zone8\">   Zone-8";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"zoneX\">   Execute all zones";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"stop\">   Stop irrigation";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"radio\" name=\"zone\" value=\"auto-OR-man\">   Automatic or manual mode";
  htmlpage += "<br><br>";
}

void webpage_Execute()
{
  String strAutoPilotMode = "";

  if(autoPilot)
  {
    strAutoPilotMode = "automatic";
  }
  else
  {
    strAutoPilotMode  = "manual";
  }
  
  htmlpage = "";  // reset webpage to this form - else will have multiple pages...
  webpageMain();

  htmlpage += "<br>";
  htmlpage += "<input type=\"submit\">";
  htmlpage += "<br><br>";
  htmlpage += "<input type=\"button\" value=\"Refresh\" onclick=\"reloadPage()\" />";
  htmlpage += "</form>";
  htmlpage += "<br><br>";
  htmlpage += "Irrigation mode : " + strAutoPilotMode + "";
  htmlpage += "<br><br>";
  htmlpage += "Last execution time  " + autoLastrunTime + "";
  htmlpage += "<br><br>";
  htmlpage += "Last check UTC time  " + thisTime + "";
  htmlpage += "<br>";
  htmlpage += "</center>";
  htmlpage += "</h5>";
  htmlpage += "</div></body></html>";

  server.send(200, "text/html", htmlpage);
}


void returnFail(String msg)
{
  server.sendHeader("Connection", "close");
  server.sendHeader("Access-Control-Allow-Origin", "*");
  server.send(500, "text/plain", msg + "\r\n");
}

 void handleSubmit()
{
  if (!server.hasArg("zone")) return returnFail("BAD ARGS");
  String val_Zone = server.arg("zone");

  if (val_Zone == "zone1") {
	  Relay_off();
	  Execute_Zone(Zone_1);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone2") {
	  Relay_off();
	  Execute_Zone(Zone_2);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone3") {
	  Relay_off();
	  Execute_Zone(Zone_3);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone4") {
	  Relay_off();
	  Execute_Zone(Zone_4);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone5") {
	  Relay_off();
	  Execute_Zone(Zone_5);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone6") {
	  Relay_off();
	  Execute_Zone(Zone_6);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone7") {
	  Relay_off();
	  Execute_Zone(Zone_7);
    webpage_Execute();
  }
  
  else if (val_Zone == "zone8") {
	  Relay_off();
	  Execute_Zone(Zone_8);
    webpage_Execute();
  }

  else if (val_Zone == "zoneX") {                          // Execute all zones
	  Relay_off();
    allZones_flag = true;
    allZonesTimer_flag = true;
    allZones_counter = 1;                                  // Execution for all zones will be set to zone 1
    webpage_Execute();
  }
  
  else if (val_Zone == "stop") {
	  Relay_off();
    allZones_flag = false;
    allZonesTimer_flag = false;
    webpage_Execute();
  }

  else if (val_Zone == "auto-OR-man") {                           // Automatic or manual mode
    bool SetAutomode;

    if(autoPilot) 
      {SetAutomode = false;}
    else
      {SetAutomode = true;}

	  autoMode_onORoff(SetAutomode);
    webpage_Execute();
  }
  
  else {webpage_Execute(); }
}

void handleRoot()
{
  if (server.hasArg("zone")) 
  {
    webpage_Execute();
	  handleSubmit();
  }
  else {
    webpage_Execute();
  }
}

void returnOK()
{
  server.sendHeader("Connection", "close");
  server.sendHeader("Access-Control-Allow-Origin", "*");
  server.send(200, "text/plain", "OK\r\n");
}

void handleNotFound()
{
  String message = "File Not Found\n\n";
  message += "URI: ";
  message += server.uri();
  message += "\nMethod: ";
  message += (server.method() == HTTP_GET)?"GET":"POST";
  message += "\nArguments: ";
  message += server.args();
  message += "\n";
  for (uint8_t i=0; i<server.args(); i++){
    message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
  }
  server.send(404, "text/plain", message);
}

void updateClock()
{
  if ( (millis() - lastGetTimeClock) >= 900000UL)       // every 15min = 900000UL - updates clock time every 30min = 1800000UL - update every hour = 3600000UL
  {
    time_t now; 
    struct tm * timeNow;
    time(&now);
    timeNow = localtime(&now);  

    int setDay  = timeNow->tm_mday;
    int setHour = timeNow->tm_hour;         
    int setMin  = timeNow->tm_min;

    char snumDay[5];
    char snumHour[5];
    char snumMin[5];
    
    String thisDay  = itoa(setDay, snumDay, 10);     // use only to display in html page
    String thisHour = itoa(setHour, snumHour, 10);   // use only to display in html page
    String thisMin  = itoa(setMin, snumMin, 10);     // use only to display in html page

    thisTime = "DayOfWeek:" + thisDay + "   Time:" + thisHour + "-" + thisMin;
    
    
    if(setDay % 2 == 0)                       // if day is even (ex.: 2, 4, 8, 10, etc.) disable auto pilot
    {
      flag_isAutoDay = false;                 // autoPilot = false;
      flag_isAutoDay_notExecute = true;       // Reset the flag autoIrrigation to 'Execute' when odd day is coming
      flag_isAutoHourReady = false;
    }
    else                                      // day is odd (ex.: 5, 11, 15, 17, etc.) Set auto Pilot to 'true'
    {
      flag_isAutoDay = true;
      if(setHour == 6)
      {
        flag_isAutoHourReady = true;         
      }
      else{flag_isAutoHourReady = false;}     // change flag value - before and after the 'authorize set time'
    }
  
  lastGetTimeClock = millis();                // Reset lastGetTimeClock counter
  }
    
}

// ================================= End SubRoutines 

void setup()
{
	Serial.begin(115200);                // Serial Window (debugging)
  EEPROM.begin(32);                    
	Wire.begin();                        // I2C Two Wire initialisation

	// PCF8575 - Turn OFF all pins by sending a high byte (1 bit per byte)
	Wire.beginTransmission(address);
	Wire.write(lowByte(Zone_off));
	Wire.write(highByte(Zone_off));
	Wire.endTransmission();

	// ----- wifi 
	WiFi.hostname(host_name);

  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
   	delay(1200);
   	Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println("hostname : ");
  Serial.println(WiFi.hostname());
	// ----- end of wifi 

	// ----- Set Time with UTP
  configTime(timezone, 0, ntpServer);
  while (now < EPOCH_1_1_2019)
  {
    now = time(nullptr);
    delay(500);
    Serial.print("*");
  }
  
  // Read EEProm memory and set irrigation for automatic or manual mode
  EEaddress = 0;
  autoPilot = EEPROM.read(EEaddress);

  // Enable server mode
  server.on("/", handleRoot);
  server.onNotFound(handleNotFound);
	server.begin();                  //Start server
	Serial.println("HTTP server started");

}


void loop(void)
{
  updateClock();
  server.handleClient();

  if(autoPilot)                             // Enable or Disable the 'Automatic irrigation' 
    {
      if(flag_isAutoDay && flag_isAutoDay_notExecute && flag_isAutoHourReady)    // start irrigation system 
      {
        flag_isAutoDay_notExecute = false;  // Prevent re-executing this 'if statement'
        
        allZones_flag = true;               // Ready to Execute all zones (1 to 8)
        allZonesTimer_flag = true;          // Ready - Permit to re-enter the all zones 'if statement' when zone X delay is finish
        allZones_counter = 1;               // Reset order (zone 1 to 8) to start at zone 1
        
        autoLastrunTime = thisTime;  // Record time when AutoPilot is ready to execute all zones
      }

    } // end of if condition

  if(zoneTimerState == 1)                   // if irrigation is running - validate time left from timer
  {
    unsigned long ZoneTimerNow = millis();

    if(ZoneTimerNow - zoneTimerPrevious >= zoneTimerInterval )
    {
        zoneTimerPrevious = ZoneTimerNow;
        Relay_off();
        allZonesTimer_flag = true;    // USED only by allZones_flag 'if condition' in void loop - Will wait until timer is finish 
                                      // before executing another zone...
    }
  }

  
  if(allZones_flag == true && allZonesTimer_flag == true)
  {
    switch (allZones_counter)
    {
      case 1:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_1);
        break;
      
      case 2:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_2);
        break;

      case 3:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_3);
        break;

      case 4:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_4);
        break;

      case 5:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_5);
        break;

      case 6:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_6);
        break;

      case 7:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_7);
        break;

      case 8:
        allZones_counter++ ;              // increment counter for next zone to execute after timer 
        allZonesTimer_flag = false;       // disable 'if condition' because timer is not finished and not starting another zone
        Execute_Zone(Zone_8);
          
        allZones_flag = false;            // All zones are executed.  Now disable the 'if condition - allZones_flag' from void loop
        break;
    }
  } // end for executing allzones

}

Credits

Mario DArrisso

Mario DArrisso

2 projects • 2 followers
Daytime IT consultant and electronic DIY on weekends...

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