delete file from SD and call HTTP

Official Hardware Classic Yún
1

Hello. I have a problem with my arduino yun. I can use the wifi , read and write from the sd without problems but if I cancel a file from the SD after I cant communicate with the internet.

Here is a sketch for test

#include <SPI.h>
#include <Wire.h>
#include <Bridge.h>
#include <HttpClient.h>
#include <FileIO.h>


HttpClient client;
Process mioProcessoLinux;

void setup() {
    Bridge.begin();
  Serial.begin(19200);
  while(!Serial);
    Serial.println("seriale avviata");
   
  if (!FileSystem.begin() ) {    
    Serial.println("Cant use SD!");
  }
  else
    Serial.println("Ok it works");
    
  File mioFile = FileSystem.open("/mnt/sd/valori.txt", FILE_APPEND);
       if (mioFile) {

          mioFile.println("I hope it would work");
          mioFile.close();
          }
}



void loop() {
  // put your main code here, to run repeatedly:
      mioProcessoLinux.begin("curl");
      mioProcessoLinux.addParameter("-i");    //stampo l'header
     
      mioProcessoLinux.addParameter("http://arduino.cc/asciilogo.txt");
      mioProcessoLinux.run();
      while (client.available()) {
        char c = client.read();
        Serial.print(c);
      }
      Serial.flush();
         
      Serial.print("linux ");
      Serial.println(mioProcessoLinux.exitValue());

      FileSystem.remove("/mnt/sd/valori.txt");      //After this HTTP does not work!!!

      mioProcessoLinux.begin("curl");
      mioProcessoLinux.addParameter("-i");    //stampo l'header
     
      mioProcessoLinux.addParameter("http://arduino.cc/asciilogo.txt");
      mioProcessoLinux.run();
      while (client.available()) {
        char c = client.read();
        Serial.print(c);
      }
      Serial.flush();
         
      Serial.print("linux ");
      Serial.println(mioProcessoLinux.exitValue());

      delay(1000);
}

Do anyone have the same problem?
Any idea about how to solve this strange behaviour?

Thanks in advance for any help!

2

I can't help with your issue but I see an error in your code. You wrote

FileSystem.remove("valori.txt");

while it must be

FileSystem.remove("/mnt/sd/valori.txt");
3

You are right. In my real sketch it was ok, in this example I forgot "/mnt/sd/". Thanks!
Anyway the problem is not this one so any other suggestion would be really appreciated.
Thanks in advance

4

Not a solution to your problem as it stands but have you used Process to get the Linux side to delete the file.

mioProcessoLinux.begin("rm");
mioProcessoLinux.addParameter("-f");
mioProcessoLinux.addParameter("/mnt/sd/valori.txt");
mioProcessoLinux.run();

Would identify whether the file can actually be deleted.

5 
#include <FileIO.h>
void setup() {
  Bridge.begin();
  Serial.begin(19200);
  while (!Serial);
  Serial.println("seriale avviata");
  if (!FileSystem.begin() ) {
    Serial.println("Cant use SD!");
  }
  else
    Serial.println("Ok it works");
  File mioFile = FileSystem.open("/mnt/sda1/valori.txt", FILE_APPEND);
  if (mioFile) {
    mioFile.println("I hope it would work");
    mioFile.close();
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  Process mioProcessoLinux;
  mioProcessoLinux.begin("curl");
  mioProcessoLinux.addParameter("-i");    //stampo l'header
  mioProcessoLinux.addParameter("http://arduino.cc/asciilogo.txt");
  mioProcessoLinux.run();
  while (mioProcessoLinux.available()) {
    char c = mioProcessoLinux.read();
    Serial.print(c);
  }
  Serial.flush();
  Serial.print("linux ");
  Serial.println(mioProcessoLinux.exitValue());
  FileSystem.remove("/mnt/sda1/valori.txt");      
  mioProcessoLinux.begin("curl");
  mioProcessoLinux.addParameter("-i");    //stampo l'header
  mioProcessoLinux.addParameter("http://arduino.cc/asciilogo.txt");
  mioProcessoLinux.run();
  while (mioProcessoLinux.available()) {
    char c = mioProcessoLinux.read();
    Serial.print(c);
  }
  Serial.flush();
  Serial.print("linux2 ");
  Serial.println(mioProcessoLinux.exitValue());
  delay(10000);
}
6

thanks sonnyyu and wildpalms. Using sonnyyu solution I have understood that the problem was in calling client.available and client read instead of mioProcessoLinux.available() mioProcessoLinux.read(). Strange...

7

sonnyyu why did you declared "Process mioProcessoLinux" in every loop and not only as global variable used by setup and loop?
thanks

8

cantore:
sonnyyu why did you declared "Process mioProcessoLinux" in every loop and not only as global variable used by setup and loop?
thanks

  1. Variable Scope: mioProcessoLinux declared as local variables, local variables are a useful way to insure that only one function has access to its own variables. This prevents programming errors when one function inadvertently modifies variables used by another function.

  2. delay(10000); : The time to declare mioProcessoLinux compare "10000" is next to nothing.