Timer SH1106

#define D5 (14)
#define D6 (12)
#define RX (3)

#define PUMP_PIN RX 

//#include <Adafruit_SSD1306.h>
#include "SH1106Wire.h"
//#include <Adafruit_GFX.h>
#include <ESP8266WiFi.h>
//#include <Wire.h>
#include <Timer.h>
#include <SoftwareSerial.h>
//#include <SPI.h>

//Adafruit_SSD1306 display(128, 64, &Wire, -1);
SH1106Wire display(0x3c, SDA, SCL);
SoftwareSerial mySerial(D5, D6);
Timer t;


bool displayOn = true;
int timerCount = 0;
int prevTimerCount = 0;
bool timerStarted = false;
long timerStartMillis = 0;
long timerStopMillis = 0;
long timerDisplayOffMillis = 0;
long serialUpdateMillis = 0;

const byte numChars = 32;
char receivedChars[numChars];
static byte ndx = 0;
char endMarker = '\n';
char rc;

void setup() {
  WiFi.mode(WIFI_OFF);
  Serial.begin(9600);
  mySerial.begin(9600);
  
  
  display.init();
  display.setContrast(255); 
  display.flipScreenVertically();
  display.clear();
  display.display();
  t.every(100, updateDisplay);
  mySerial.write(0x11);


  pinMode(PUMP_PIN, INPUT_PULLUP);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);

  

  memset(receivedChars, 0, numChars );

  
  
}

void loop() {
  t.update();
  detectChanges();
  getMachineInput();
}

void getMachineInput() {
  while (mySerial.available() ) {
    serialUpdateMillis = millis();
    rc = mySerial.read();

    if (rc != endMarker) {
      receivedChars[ndx] = rc;
      ndx++;
      if (ndx >= numChars) {
        ndx = numChars - 1;
      }
    } else {
      receivedChars[ndx] = '\0';
      ndx = 0;
      Serial.println(receivedChars);
    }
  }

  if (millis() - serialUpdateMillis > 5000) {
    serialUpdateMillis = millis();
    memset(receivedChars, 0, numChars );
    Serial.println("Request serial update");
    mySerial.write(0x11);
  }
}

void detectChanges() {
  digitalWrite(LED_BUILTIN, digitalRead(PUMP_PIN));
  if (!timerStarted && !digitalRead(PUMP_PIN)) {
    timerStartMillis = millis();
    timerStarted = true;
    displayOn = true;
    Serial.println("Start pump");
  }
  if (timerStarted && digitalRead(PUMP_PIN)) {
    if (timerStopMillis == 0) {
      timerStopMillis = millis();
    }
    if (millis() - timerStopMillis > 500) {
      timerStarted = false;
      timerStopMillis = 0;
      timerDisplayOffMillis = millis();
      //display.invert(false);
      Serial.println("Stop pump");
    }
  } else {
    timerStopMillis = 0;
  }
  if (!timerStarted && displayOn && timerDisplayOffMillis >= 0 && (millis() - timerDisplayOffMillis > 1000 * 20 * 20)) {
    timerDisplayOffMillis = 0;
    timerCount = 0;
    prevTimerCount = 0;
    displayOn = false;
    Serial.println("Sleep");
  }
}

String getTimer() {
  char outMin[2];
  if (timerStarted) {
    timerCount = (millis() - timerStartMillis ) / 1000;
    if (timerCount > 15) {
      prevTimerCount = timerCount;
    }
  } else {
    timerCount = prevTimerCount;
  }
  if (timerCount > 99) {
    return "99";
  }
  sprintf( outMin, "%02u", timerCount);
  return outMin;
}

void updateDisplay() {
  display.clear();
  if (displayOn) {
    if (timerStarted) {
      display.setFont(DSEG7_Classic_Regular_50);
      display.drawString(25, 2, getTimer());
    } else {
      // draw line
      display.drawVerticalLine(80,0,100);
      // draw time seconds
      display.setFont(DSEG7_Classic_Regular_30);
      display.drawString(82,13, getTimer());
      // draw machine state C/S
       if (receivedChars[0] ) {
        display.setFont(Roboto_Light_13);
        display.drawString(0,2, "MODE");
        display.setFont(DSEG14_Classic_Regular_13);
       if (String(receivedChars[0]) == "C") {
          display.drawString(50,0, "C");
        } else if (String(receivedChars[0]) == "V") {
          display.drawString(50,0, "S");
        } else {
          display.drawString(50,0, "X");
        }
      }
      if (String(receivedChars).substring(18, 22) == "0000") {
        // not in boost heating mode
        // draw fill circle if heating on
        if (String(receivedChars[23]) == "1") {
          display.fillCircle(69, 8, 7);
        }
        // draw empty circle if heating off
        if (String(receivedChars[23]) == "0") {
          display.drawCircle(69, 8, 7);
        }
      } else {
        // in boost heating mode
        // draw fill rectangle if heating on
        if (String(receivedChars[23]) == "1") {
          display.fillRect(63, 2, 14, 13);
        }
        // draw empty rectangle if heating off
        if (String(receivedChars[23]) == "0") {
          display.drawRect(63, 2, 14, 13);
        }
      }
      // draw temperature
      if (receivedChars[14] && receivedChars[15] && receivedChars[16]) {
        display.setFont(Roboto_Light_30);
        //display.setCursor(1, 20);
        if (String(receivedChars[14]) != "0") {
          display.drawString(0,15,(String(receivedChars[14])));
        }
        display.drawString(13,15,(String(receivedChars[15])));
        display.drawString(29,15,(String(receivedChars[16])));
        //display.print((char)247);
        display.setFont(Roboto_Light_30);
        display.drawString(46,16, "°");
        if (String(receivedChars[14]) == "0") {
          display.setFont(DSEG14_Classic_Regular_13);
          display.drawString(58,20, "C");
       
         
        }
      }
      // draw steam temperature
      if (receivedChars[6] && receivedChars[7] && receivedChars[8]) {
        display.setFont(ArialMT_Plain_16);
        //display.setCursor(1, 48);
        if (String(receivedChars[6]) != "0") {
          display.drawString(3,47,(String(receivedChars[6])));
        }
        display.drawString(12,47,(String(receivedChars[7])));
        display.drawString(22,47,(String(receivedChars[8])));
        display.drawString(32,47, "°");
        display.setFont(DSEG14_Classic_Regular_10);
        display.drawString(40,49,"C");
      }
    }
  }
  display.display();
}