read file

readfromserial.ino

#include "FS.h"
#include "SD.h"
#include "SPI.h"

File myFile;


bool FILE_IS_OPEN  = false;
int nb_bytes=0;
void setup() {
  Serial.begin(1000000);
  SD.begin(5, SPI, 80000000);
  pinMode(15, INPUT_PULLUP);
}

void loop() {

  if (digitalRead(15) == LOW) {
    Serial.println("we start...");
    while (Serial.available()) Serial.read();
    delay(5000);
    Serial.println("ready ...");
  }

  while (digitalRead(15) == LOW) {
    if (!FILE_IS_OPEN) {
      Serial.println("we open the files...");
      myFile = SD.open("/video1.txt", FILE_WRITE);
      FILE_IS_OPEN = true;
    }
    while (Serial.available() && myFile) {
      nb_bytes++;
      byte b = Serial.read();
      myFile.write(b);
      Serial.write(b);
    }
  }
  if (FILE_IS_OPEN) {
     Serial.println("we close the files...");
    myFile.close();
    Serial.printf("we've cloed with %d bytes\n",nb_bytes);
    FILE_IS_OPEN = false;
  }
}