How to Free My RAM?

Projects Programming
1

Hi @ All.

First i want to tell u what i need. then i tell u what my project does so u can find a better solution.

I want to Flush or Delete the RAM after every time my loop ends. ( or at least save this till the next stuff comes in ).
i dont know how to describe it better.

i set up a Costum page where my Arduino Mega Connect to with HTTP GET and he gets header Infos and a costum string " {0:0:0} " <- each number lights up an LED.

After X runs the LED all go out and the arduino stops. i dont want to manage my RAM better i want to clean all that not is from my Programm.

kind regarts Kiki

2

No need to do any thing like that. The stack is automatical freed at the end of a function call and the global data is just reused!.

Mark

3

Just open the gate and let him out. First ewe see him, then ewe don't :slight_smile:
Sorry just had to.

Edit: Sorry no offence was intended :frowning:

4

I searched the web for Hours, then i decided to post here to get this answers ...
As i said i need a way to clean my RAM..

holmes4:
No need to do any thing like that. The stack is automatical freed at the end of a function call and the global data is just reused!.

Mark

my RAM is full after X loops around 200-300
I did memoryFree to watch the mem and it drops from 6000free to 200 and then arduino just delivers 0:0:0 cause he cant process more data from server.

but what to say its the INTERNET where people make FUN of PEOPLE....

5

KikiTheOne:
I searched the web for Hours, then i decided to post here to get this answers ...

But you didn't think posting your code might be a good idea?

6

KikiTheOne:
I did memoryFree to watch the mem and it drops from 6000free to 200 and then arduino just delivers 0:0:0

You need to find the memory leak and plug it.

7

.ino

#include <SPI.h>
#include <Ethernet.h>
#include <String.h>


char myserver[] = "www.elohunter.net";
EthernetClient client;
String Input = "";
boolean StartCostum = true;
int LEDROT=53;
int LEDGRUEN=49;
int LEDBLAU=45;
//////////////////////

void setup(){
	pinMode(LEDROT, OUTPUT);
	digitalWrite(LEDROT, LOW);
	
	pinMode(LEDGRUEN, OUTPUT);
	digitalWrite(LEDGRUEN, LOW);
	
	pinMode(LEDBLAU, OUTPUT);
	digitalWrite(LEDBLAU, LOW);

	Ethernet.begin(mac);
	Serial.begin(9600); 
	Serial.println("Connecter Test");
}

void loop(){
  StartCostum = true;
  sendGET(); // call sendGET function below when byte is an e
  Serial.println(freeRam ());
} 

//////////////////////////
int freeRam ()
{
extern int __heap_start, *__brkval;
int v;
return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
}

void sendGET() //client function to send/receive GET request data.
{
	if(StartCostum==true)
	{
		if (client.connect(myserver, 80)) {  //starts client connection, checks for connection
			delay(250);
			client.println("GET /projects/1/index.php HTTP/1.0"); //download text
			client.println("Host: www.elohunter.net");
			client.println("User-Agent: ARD1-MEGA-ELOHUNTER");
			client.println(); //end of get request
		} 
		else {
			Serial.println("connection failed"); //error message if no client connect
			Serial.println();
		}

		while(client.connected() && !client.available()) delay(50); //waits for data
		while (client.connected() || client.available()) { 
			char d = client.read();
			String e = String(d);
			Input += e;
		}
		
		int firstClosingBracket = Input.indexOf('{');
		int lastClosingBracket = Input.indexOf('}');
		
		String Output_Coding = Input.substring(firstClosingBracket+1,lastClosingBracket);
		
		String Rval = getValue(Output_Coding, ':', 0);
		String Gval = getValue(Output_Coding, ':', 1);
		String Bval = getValue(Output_Coding, ':', 2);
		
		if(Rval.toInt()==1){digitalWrite(LEDROT, HIGH);}else{digitalWrite(LEDROT, LOW);}
		if(Gval.toInt()==1){digitalWrite(LEDGRUEN, HIGH);}else{digitalWrite(LEDGRUEN, LOW);}
		if(Bval.toInt()==1){digitalWrite(LEDBLAU, HIGH);}else{digitalWrite(LEDBLAU, LOW);}

		client.stop(); //stop client
		Input = "";
		StartCostum = false;
	}
}

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]) : "";
}

.php

if($_SERVER['HTTP_USER_AGENT']=='ARD1-MEGA-ELOHUNTER')
{
	include(".sql.php");

	print '{';

	$get_color = mysql_query("SELECT * FROM `project1_color_settings`");
	$count = 0;
	while($row = mysql_fetch_assoc($get_color))
	{
		if($count!=0){print ':';}
		print $row['value'];
		$count = $count + 1;
	}
	
	print '}';
}

The Problem is not the Server or the MYSQL in the PHP.
Freemem gives me like i said 6000~ back and then 2xx and then it stops the GET from server, but its still connected

8

Why is String Input = "" a global variable?

You should define this within sendGET Then the valuable memory it is wasting would be recovered as the sendGet function completes.

9

Three things.

  1. Never use String on the Arduinos. Aways use string.

  2. You have very little SRAM and a HTTP response will use it all up very quickly.

  3. String e = String(d);
    This is not the way to add a char to a string and is almost certainly the cause of your memory leak.

Mark

10

KenF:
Why is String Input = "" a global variable?

You should define this within sendGET Then the valuable memory it is wasting would be recovered as the sendGet function completes.

done
thanks for that

holmes4:
Three things.

  1. Never use String on the Arduinos. Aways use string.

  2. You have very little SRAM and a HTTP response will use it all up very quickly.

  3. String e = String(d);
    This is not the way to add a char to a string and is almost certainly the cause of your memory leak.

Mark

#1 what alternative could i use. i have to explode the string i get and the only way i found was this, if u have any ideas let me know :slight_smile:

#2 it can handle the response the header is not that big.

HTTP/1.1 200 OK
Date: Mon, 10 Nov 2014 12:58:19 GMT
Server: Apache/2.2.29 (Unix)
X-Powered-By: PHP/5.3.29
Connection: close
Content-Type: text/html
{1:1:1}

thats why i asked for the flush of RAM but now i already did what KenF said and i will test if that was the trick

#3 "String e = String(d);"
i have to convert the "d" to a String otherwhise it says cant ADD String on CHAR

thx alot so far. i will test this fixxes now and respond shortly

11

i have to convert the "d" to a String otherwhise it says cant ADD String on CHAR

Of course you can add a char to a String.

what alternative could i use. i have to explode the string i get and the only way i found was this, if u have any ideas let me know

There is in C/C++ a huge difference between String and string.!!!

Mark

12

I ran it for nearly 1 hour now and it looks like its still working fine. :slight_smile: i guess the

KenF:
Why is String Input = "" a global variable?

You should define this within sendGET Then the valuable memory it is wasting would be recovered as the sendGet function completes.

done the trick.
i keep watching thx so far :smiley:

13

Well thanks for the feedback. It's surprising how many people just get the answer then never return.

14

KenF:
Just open the gate and let him out. First ewe see him, then ewe don't :slight_smile:
Sorry just had to.

Edit: Sorry no offence was intended :frowning:

Ewe got there before me. But I had only thought of the gate.

...R