How to save sensor value in EEPROM? (ESP8266)?

Question

I would like to save the height of a tank in case of power outage with EEPROM and every time I reboot the board. However, I could not do so after using EEPROM.commit() , EEPROM.get and EEPROM.put as the reading of the height tank changes every time I tried to reboot it . Am I using it wrongly?

I used EEPROM.get , EEPROM.put , EEPROM.commit in the void setup section so that it will save the data during boot up. However, the tank height just change whenever I changed to a different tank with different height after boot up.

How could I recalibrate the height of the tank if I would like to change to another tank one day, can I just click the RST button on the ESP8266 board?

Thank you

#include <LiquidCrystal_I2C.h>  //1602 LCD library
#include <Wire.h>
#include <EEPROM.h>
#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>  //NodeMCU ESP8266 library
#include <BlynkSimpleEsp8266.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);


WidgetLED led1(V2);


 
char auth[] = ""; //Enter your Auth token
char ssid[] = ""; //Enter your WIFI name
char pass[] = ""; //Enter your WIFI password
 
BlynkTimer timer;
bool pinValue = 1;


long duration;
int distance; 
int percentage;
int addr=0;
float tankheight, val;

 
#define trig D7
#define echo D8
#define relay D5
 
void setup() {
  Serial.begin(9600);
  EEPROM.begin(512);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(relay, OUTPUT);
  Wire.begin(D2, D1);
  lcd.init();
  lcd.backlight();
  Blynk.begin(auth, ssid, pass);
  digitalWrite(trig, LOW);
  delayMicroseconds(4);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  duration = pulseIn(echo, HIGH);
  tankheight = duration * 0.034 / 2;
  Serial.print("Tank height");
  Serial.print(tankheight);
  EEPROM.put(addr, tankheight);
  EEPROM.commit();
  val=EEPROM.get(addr, tankheight);
  Serial.print("Addr");
  Serial.print(val);
  timer.setInterval(1L, Wlevel);
  digitalWrite(relay, HIGH);
}
 


BLYNK_CONNECTED(){
  Blynk.syncAll();

  }
 
BLYNK_WRITE(V0) {
  pinValue = param.asInt();

}



void loop() {
  Blynk.run();
  timer.run();
  WiFi.setSleepMode(WIFI_NONE_SLEEP);

}

void Wlevel(){  // Initialize detecting water level and relay)
  {
  digitalWrite(trig, LOW);
  delayMicroseconds(4);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  duration = pulseIn(echo, HIGH);
  distance = duration * 0.034 / 2;
  percentage= map(distance,val,10 ,0, 100);
 
  Blynk.virtualWrite(V1, percentage);  

  if(percentage<0)
  {
    percentage = 0;
  }
  else if(percentage>100)
  {
    percentage = 100;
  }

 }
  

 if (pinValue == 1)
    {
       if (percentage < 100)
       {
          digitalWrite(relay, LOW);
          Serial.print("Water level:");
          Serial.print(percentage);
          Serial.print("%");
          Serial.println(" Pump is ON");
          led1.on();
          lcd.setCursor(0,0);
          lcd.print("Water Lvl:");
          lcd.print(percentage);
          lcd.print("%  ");
          lcd.setCursor(0,1);
          lcd.print("Pump: ON  (AUTO)");
          
       } 
       
       else 
       {
          digitalWrite(relay, HIGH);
          Serial.println("Water level is 100%   Pump is OFF");
          led1.off();
          lcd.setCursor(0, 0);
          lcd.print("Water Lvl:");
          lcd.print(percentage);
          lcd.print("%  ");
          lcd.setCursor(0,1);
          lcd.print("Pump: OFF (AUTO)");
          
       }
    }
   else
    {
      digitalWrite(relay, HIGH);
      Serial.print("Water level:");
      Serial.print(percentage);
      Serial.print("%");
      Serial.println("System is OFF, Check Blynk");
      lcd.setCursor(0,0);
      lcd.print("Water Lvl:");
      lcd.print(percentage);
      lcd.print("%  ");
      lcd.setCursor(0,1);
      lcd.print("System is OFF   ");
      led1.off();
      
    }

   }

Answer 1

Use a different button - you may have to wire something up...

In the loop, read the button and only if it is pressed should you re-calibrate and set the value to eeprom. You can do it in setup too but then you would have to reboot with the button pressed to trigger re-calibration.

You can also read a serial command in the loop. Anything external that can be triggered with a separate intent to re-calibrate would work. A power outage resembles the normal reset too much. To execute different behavior in two different scenarios, you must be able to detect which scenario you are in.