I have an Arduino UNO R3 that reads a specific value from my Web Page.
I have an LED attached to the PIN 13 & GND of my Arduino.
When the Arduino reads 1 from my Web Page, it should turn the LED ON. When it reads 0, it should turn it off.
Following is the code for that:
#include "SIM900.h"
#include <SoftwareSerial.h>
#include "inetGSM.h"
InetGSM inet;
#define ledPin 13
char msg[165];
char store[2];
char a;
char b;
char* disp;
boolean started=false;
void setup()
{
pinMode(ledPin, OUTPUT);
digitalWrite(ledPin, LOW);
//Serial connection.
Serial.begin(9600);
Serial.println("GSM Shield testing.");
//Start configuration of shield with baudrate.
//For http uses is raccomanded to use 4800 or slower.
if (gsm.begin(2400)) {
Serial.println("\nstatus=READY");
started=true;
} else Serial.println("\nstatus=IDLE");
if(started)
{
//GPRS attach, put in order APN, username and password.
//If no needed auth let them blank.
if (inet.attachGPRS("TATA.DOCOMO.INTERNET", "", ""))
Serial.println("status=ATTACHED");
else Serial.println("status=ERROR");
delay(1000);
//TCP Client GET, send a GET request to the server and
//save the reply.
//Print the results.
}
}
void loop()
{
inet.httpGET("www.boat.esy.es", 80, "/retrieve.php", msg, 165);
disp = strstr(msg,"\r\n\r\n");
disp = disp+4;
a = disp[0];
b = disp[1];
Serial.println(b);
if(b=='1')
{
digitalWrite(ledPin, HIGH);
}
if(b=='0');
{
digitalWrite(ledPin, LOW);
}
}
Problem here is, when I disable the digitalWrite(ledPin,LOW), that is when I comment it out, the LED turns on & stays that way.
But the moment I enable it & load the code on my Arduino, it won't even turn on.
I'm wondering if it's a logical error or something else. Because the turning on & off of the LED depends completely on the conditions being satisfied. And for now, my Web Page returns only 1, hence the LED should stay on. But when I include both digitalWrite(ledPin, HIGH) and digitalWrite(ledPin, LOW) in the same code and run it, it doesn't work. I can see the Serial printing out the messages associated with the LED ON, but I don't see the LED turning ON.
Thank You for your time!!
______________________________________________________nha khoaimplant
Any ideas would be appreciated