I used two ultrasonic sensors. I want to sense the distance from both ultrasonic sensors and display some text in LCD display. I use arduino mega 2560.
This is my Arduino code
int trigPin=36; //For first sensor
int echoPin=37;
float pingTime;
float targetDistance;
float speedOfSound=776.5;
int trigPin2=38; //For second sensor
int echoPin2=39;
float pingTime2;
float targetDistance2;
// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(30, 31, 32, 33, 34, 35);
String str;
void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(trigPin2, OUTPUT);
pinMode(echoPin2, INPUT);
lcd.begin(16, 2);
lcd.setCursor(0, 2);
}
void loop() {
//Read first sensor
digitalWrite(trigPin, LOW); //Set trigger pin low
delayMicroseconds(2000); //Let signal settle
digitalWrite(trigPin, HIGH); //Set trigPin high
delayMicroseconds(15); //Delay in high state
digitalWrite(trigPin, LOW); //ping has now been sent
delayMicroseconds(10); //Delay in low state
pingTime = pulseIn(echoPin, HIGH); //pingTime is presented in microceconds
pingTime=pingTime/1000000; //convert pingTime to seconds by dividing by 1000000 (microseconds in a second)
pingTime=pingTime/3600; //convert pingtime to hourse by dividing by 3600 (seconds in an hour)
targetDistance= speedOfSound * pingTime; //This will be in miles, since speed of sound was miles per hour
targetDistance=targetDistance/2; //Remember ping travels to target and back from target, so you must divide by 2 for actual target distance.
targetDistance= targetDistance*63360; //Convert miles to inches by multipling by 63360 (inches per mile)
Serial.print(targetDistance);
//Read second sensor
digitalWrite(trigPin2, LOW); //Set trigger pin low
delayMicroseconds(2000); //Let signal settle
digitalWrite(trigPin2, HIGH); //Set trigPin high
delayMicroseconds(15); //Delay in high state
digitalWrite(trigPin2, LOW); //ping has now been sent
delayMicroseconds(10); //Delay in low state
pingTime2 = pulseIn(echoPin2, HIGH); //pingTime is presented in microceconds
pingTime2=pingTime2/1000000; //convert pingTime to seconds by dividing by 1000000 (microseconds in a second)
pingTime2=pingTime2/3600; //convert pingtime to hourse by dividing by 3600 (seconds in an hour)
targetDistance2= speedOfSound * pingTime2; //This will be in miles, since speed of sound was miles per hour
targetDistance2=targetDistance2/2; //Remember ping travels to target and back from target, so you must divide by 2 for actual target distance.
targetDistance2= targetDistance2*63360; //Convert miles to inches by multipling by 63360 (inches per mile)
Serial.println(targetDistance2);
if (Serial.available()) {
str = ""; // clear the current string content
str = Serial.readStringUntil('\n'); // read the string until new line found \n
lcd.setCursor(0, 2); // set the cursor For 0,2
if(str=="Free to park"){ // check for the first condition
lcd.clear(); // clear the LCD
lcd.print("Free to Park..!"); // print the place where cursor set
}
else if(str=="No Space"){
lcd.clear();
lcd.print("No Space..!");
}
delay(100);
}
}
this is my python code
from __future__ import print_function
import pypyodbc
import serial
import time
import datetime
s = serial.Serial('COM31', 9600)
time.sleep(2)
conn = pypyodbc.connect('DRIVER={SQL Server};SERVER=IROSHEN-PC;DATABASE=EasyParkDB')
cur = conn.cursor()
while (1==1):
#if (s.inWaiting()>0):
myData = s.readline()
myData2 = s.readline2()
#print (myData
distance = float(myData)
distance2 = float(myData2)
if(distance < 6 and distance2<6):
#cur.execute ("UPDATE TblBlock SET CurrentState=1 WHERE BlockID='3'")
cur.execute('''UPDATE TblBlock SET CurrentState='1' WHERE BlockID='3';''')
conn.commit()
print (distance)
s.write('No Space\n')
else:
cur.execute('''UPDATE TblBlock SET CurrentState='0' WHERE BlockID='3';''')
conn.commit()
print ("lk")
s.write('Free to park\n')
There is an error in line
myData = s.readline()
I don't know how to read sense data from both sensors at same time..
please help me to solve this problem........
