Whenever i write a file its not existing or empty after next boot.
Using the same sketch on an Wemos D1 mini its works without problems. Actually im only facing this problem on a ESP-01.
I reproduced this problem on several different ESP-01. So seems not to be hardware related
Hardware: ESP-01
Core Version: 2.4.0
Settings in IDE
Module: Generic ESP8266 Module
Flash Size: 1MB (64k SPIFFS), also tried with 512k (64k SPIFFS)
CPU Frequency: 80Mhz
Flash Mode: DIO
Flash Frequency: 40Mhz
Upload Using: SERIAL
Reset Method: ck
Sketch to reproduce
#include <FS.h>
void setup()
{
Serial.begin(115200);
if (!SPIFFS.begin()) Serial.println("error while mounting filesystem!");
readFile();
writeFile();
readFile();
Serial.println("done");
}
void readFile()
{
Serial.println("reading");
File f = SPIFFS.open("/myFile.txt", "r");
if (!f) Serial.println("file not available");
else if (f.available()<=0) Serial.println("file exists but available <0");
else
{
String ssidString = f.readStringUntil('#');
Serial.print("read from file: ");
Serial.println(ssidString);
}
f.close();
}
void writeFile()
{
Serial.println("writing");
File f = SPIFFS.open("/myFile.txt", "w");
if (!f) Serial.println("File creation failed");
else
{
f.print("networkConfig");
f.print("#");
f.flush();
f.close();
}
}
void loop()
{
}
Output of first run:
reading
file not available
writing
reading
read from file: <--- here we see the problem already
done
Output of second run:
eading
file not available
writing
reading
read from file:
done
Output of third run:
reading
read from file:
writing
File creation failed <---- check this!
reading
read from file:
done
Any ideas? Help is realy appreciated
thank you!
Hermann