[LORA] Add water counter sensor with example (#1941)

* Add water counter example

examples/LoraWaterCounter/src/main.cpp

@@ -0,0 +1,138 @@
+#include <LoRa.h>
+#include <SPI.h>
+#include <WiFi.h>
+#include <Wire.h>
+#include <stdio.h>
+
+#include "SSD1306.h"
+#include "rom/ets_sys.h"
+#include "soc/rtc_cntl_reg.h"
+#include "soc/sens_reg.h"
+
+#define SCK  5 // GPIO5  -- SX1278's SCK
+#define MISO 19 // GPIO19 -- SX1278's MISnO
+#define MOSI 27 // GPIO27 -- SX1278's MOSI
+#define SS   18 // GPIO18 -- SX1278's CS
+#define RST  23 // GPIO23 -- SX1278's RESET
+#define DI0  26 // GPIO26 -- SX1278's IRQ(Interrupt Request)
+#define BAND 433E6
+
+//OLED pins
+#define OLED_SDA 21
+#define OLED_SCL 22 
+//#define OLED_RST 16
+
+#define LED      25
+
+#define DHT_PIN  12
+#define DHT_TYPE DHT22 
+
+#define CNT_PIN  34
+
+#define BAT_PIN  35
+
+const int MAX_ANALOG_VAL = 4095;
+const float MAX_BATTERY_VOLTAGE = 4.2;
+
+int cntpkt = 0;
+unsigned long counter = 0;
+unsigned long last_interrupt_time = 0;
+int pulse_seen = 0;                                                   // pulse detected by interrupt function
+int bounce_delay_ms = 100;
+
+SSD1306 display(0x3c, OLED_SDA, OLED_SCL);
+String rssi = "RSSI --";
+String packSize = "--";
+String packet;
+
+DHT dht(DHT_PIN, DHT_TYPE); //Inizializza oggetto chiamato "dht", parametri: pin a cui è connesso il sensore, tipo di dht 11/22
+
+void ICACHE_RAM_ATTR bounceCheck ();
+
+void setup() {
+  pinMode(LED, OUTPUT);
+
+  //pinMode(OLED_RST, OUTPUT);
+  //digitalWrite(OLED_RST, LOW); // set GPIO16 low to reset OLED
+  //delay(50);
+  //digitalWrite(OLED_RST, HIGH); // while OLED is running, must set GPIO16 in high
+
+  Serial.begin(115200);
+  while (!Serial);
+  Serial.println();
+  Serial.println("LoRa Sender Test");
+
+  SPI.begin(SCK, MISO, MOSI, SS);
+  LoRa.setPins(SS, RST, DI0);
+  if (!LoRa.begin(BAND)) {
+    Serial.println("Starting LoRa failed!");
+    while (1);
+  }
+
+  Serial.println("init ok");
+  display.init();
+  display.flipScreenVertically();
+  display.setFont(ArialMT_Plain_10);
+
+  pinMode(BAT_PIN, INPUT); 
+  pinMode(CNT_PIN, INPUT_PULLUP);
+  
+  attachInterrupt (CNT_PIN, bounceCheck, RISING);
+
+  delay(1500);
+}
+
+void loop() {
+  display.clear();
+  display.setTextAlignment(TEXT_ALIGN_LEFT);
+  display.setFont(ArialMT_Plain_10);
+
+  display.drawString(0, 0, "Sending packet: ");
+  display.drawString(90, 0, String(cntpkt));
+
+  String NodeId = WiFi.macAddress();
+  float temp = dht.readTemperature();
+  float hum = dht.readHumidity();
+  float battery = getBattery();
+  // send packet
+  LoRa.beginPacket();
+  // Build json string to send
+  //per test rimuovere
+
+  String msg = "{\"model\":\"ESP32CNT\",\"id\":\"" + NodeId + "\",\"count\":\"" + String(counter) + "\",\"tempc\":\"" + String(temp) + "\",\"hum\":\"" + String(hum) + "\",\"batt\":\"" + String(battery) + "\"}";
+  // Send json string
+  LoRa.print(msg);
+  LoRa.endPacket();
+
+  Serial.println(msg);
+  
+  display.drawString(0, 15, String(NodeId));
+  display.drawString(0, 30, "count: " + String(counter));
+  display.drawString(0, 45, "battery: " + String(battery)+ " %");
+  display.display();
+
+  delay(5000);
+
+  cntpkt++;
+
+  digitalWrite(LED, HIGH); // turn the LED on (HIGH is the voltage level)
+  delay(1000); // wait for a second
+  digitalWrite(LED, LOW); // turn the LED off by making the voltage LOW
+  delay(60000); // wait for 60 seconds
+}
+
+void ICACHE_RAM_ATTR bounceCheck (){
+   unsigned long interrupt_time = millis();
+   if (interrupt_time - last_interrupt_time > bounce_delay_ms) counter++;    // void loop() then notes pulse == 1 and takes action      
+   last_interrupt_time = interrupt_time;
+}
+
+float getBattery(void) {
+  int rawValue = analogRead(BAT_PIN);
+
+  float voltageLevel = (rawValue / 4095.0) * 2 * 1.1 * 3.3; // calculate voltage level
+  float perc = voltageLevel / MAX_BATTERY_VOLTAGE * 100;
+
+  return(perc);
+}
+