I am a college undergraduate currently doing my term paper about a iot parking system using an ultrasonic sensor and wifi module. The ultrasonic sensor is used to determine the vacancy of the parking slot and a rgb module is used to indicate the the status (green - vacant, red - occupied). The esp8266 is used to communicate between the prototype and the cloud/app.
I am currently using blynk app to test the connectivity of my prototype and application. I have put 3 leds in the template of the app to indicate also the status of the 3 slots.
Now, I want to add another feature. If i press a button in the blynk app, a yellow led (reserved) will light up and when the ultrasonic detects that the slot is already occupied, the yellow led will turn off and the red led will turn on. Can anyone help me?
//arduino code//
#include <SoftwareSerial.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
SoftwareSerial nodemcu (2,3);
LiquidCrystal_I2C lcd (0x27, 16, 2);
const int trig1 = 13;
const int echo1 = 12;
const int trig2 = 11;
const int echo2 = 10;
const int trig3 = 9;
const int echo3 = 8;
const int r1 = 7;
const int g1 = 6;
const int r2 = 5;
const int g2 = 4;
const int r3 = 3;
const int g3 = 2;
int duration1 = 0;
int distance1 = 0;
int duration2 = 0;
int distance2 = 0;
int duration3 = 0;
int distance3 = 0;
int count = 0;
int freeslot = 0;
int s1 = 0;
int s2 = 0;
int s3 = 0;
String sensor1;
String sensor2;
String sensor3;
String cdata = "";
void setup()
{
pinMode(trig1 , OUTPUT);
pinMode(echo1 , INPUT);
pinMode(trig2 , OUTPUT);
pinMode(echo2 , INPUT);
pinMode(trig3 , OUTPUT);
pinMode(echo3 , INPUT);
pinMode(r1, OUTPUT);
pinMode(g1, OUTPUT);
pinMode(r2, OUTPUT);
pinMode(g2, OUTPUT);
lcd.begin();
lcd.backlight();
Serial.begin(9600);
nodemcu.begin(9600);
}
void loop()
{
cdata = cdata + sensor1+" ,"+sensor2+" ,"+sensor3;
Serial.println(cdata);
nodemcu.println(cdata);
digitalWrite(trig1, HIGH);
delayMicroseconds(1000);
digitalWrite(trig1, LOW);
duration1 = pulseIn(echo1, HIGH);
distance1 = (duration1/2) / 28.5;
delay(1000);
cdata = "";
if (distance1 <= 50) {
s1 = 1;
sensor1 = "0";
digitalWrite(r1, HIGH);
digitalWrite(g1, LOW);
Serial.print ("s1: OCCUPIED");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.print("SLOT1: OCCUPIED");
delay(1000);
lcd.clear();
} else {
s1 = 0;
sensor1 = "255";
digitalWrite(g1, HIGH);
digitalWrite(r1, LOW);
Serial.print ("s1: VACANT");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.print("SLOT1: VACANT");
delay(1000);
lcd.clear();
}
digitalWrite(trig2, HIGH);
delayMicroseconds(1000);
digitalWrite(trig2, LOW);
duration2 = pulseIn(echo2, HIGH);
distance2 = (duration2/2) / 28.5;
delay(1000);
if (distance2 <=50) {
s2 = 1;
sensor2 = "0";
digitalWrite(r2, HIGH);
digitalWrite(g2, LOW);
Serial.print (" ,s2: OCCUPIED");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.print("SLOT2: OCCUPIED");
delay(1000);
lcd.clear();
} else {
s2 = 0;
sensor2 = "255";
digitalWrite(r2, LOW);
digitalWrite(g2, HIGH);
Serial.print (" ,s2: VACANT");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.print("SLOT2: VACANT");
delay(1000);
lcd.clear();
}
digitalWrite(trig3, HIGH);
delayMicroseconds(1000);
digitalWrite(trig3, LOW);
duration3 = pulseIn(echo3, HIGH);
distance3 = (duration3/2) / 28.5;
delay(1000);
if (distance3 <=50) {
s3 = 1;
sensor3 = "0";
digitalWrite(r3, HIGH);
digitalWrite(g3, LOW);
Serial.print (" ,s3: OCCUPIED");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.println("SLOT3: OCCUPIED");
delay(1000);
lcd.clear();
} else {
s3 = 0;
sensor3 = "255";
digitalWrite(r3, LOW);
digitalWrite(g3, HIGH);
Serial.println(" ,s3: VACANT");
lcd.print("INTRAMUROADS");
lcd.setCursor(0,1);
lcd.println("SLOT3: VACANT");
delay(1000);
lcd.clear();
}
count = s1 + s2 + s3;
freeslot = 3 - count;
Serial.print("Free slot :");
Serial.println(freeslot);
}//esp8266 code//
#define BLYNK_PRINT Serial
#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <SoftwareSerial.h>
char auth [] = "authkey";
char ssid [] = "wifiname";
char pass [] = "wifipass";
SimpleTimer timer;
String myString;
char rdata;
int s1, s2, s3;
int led1, led2, led3;
void myTimerEvent () {
Blynk.virtualWrite(V1, millis()/1000);
}
void setup () {
Serial.begin(9600);
Blynk.begin(auth,ssid,pass);
timer.setInterval(100L,sr1);
timer.setInterval(100L,sr2);
timer.setInterval(100L,sr3);
}
void loop () {
if(Serial.available() == 0) {
Blynk.run();
timer.run();
}
if (Serial.available() > 0) {
rdata = Serial.read();
myString = myString+ rdata;
// Serial.println(rdata);
if(rdata == '\n') {
Serial.println(myString);
String l = getValue(myString, ',', 0);
String m = getValue(myString, ',', 1);
String n = getValue(myString, ',', 2);
led1 = l.toInt();
led2 = m.toInt();
led3 = n.toInt();
myString = "";
}
}
}
void sr1() {
int sdata = led1;
Blynk.virtualWrite(V10, sdata);
}
void sr2() {
int sdata = led2;
Blynk.virtualWrite(V11, sdata);
}
void sr3() {
int sdata = led3;
Blynk.virtualWrite(V12, sdata);
}
String getValue(String data, char separator, int index) {
int found = 0;
int strIndex[] = {0,-1};
int maxIndex = data.length() -1;
for (int i = 0; i<= maxIndex && found <= index; i++) {
if (data.charAt(i) == separator || i == maxIndex) {
found++;
strIndex[0] = strIndex[1] +1;
strIndex[1] = (i == maxIndex) ? i+1 : i;
}
}
return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
}