External EEPROM garbage

[kcpn]

I only get garbage out of my external EEPROM. I don’t think I’m writing garbage in, but I always get garbage out - further outputs are different depending of i2c speed…
My own conclusion is that either writing or reading or both are erroneous.
Can you see where I am wrong?
Any hint is much appreciated.
Thanks

uC: NodeMCU8266
EEPROM: FT24C256A
4k7 pullup on both lines to the EEPROM
I2C device found at address 0x50 ! using i2c scanner
Code for UNO taken from:

Reading and Writing Data to External EEPROM Using Arduino

Modified for NodeMCU8266

Output
Write 77777 to the EEPROM -> 326323732
Write 77777 to the EEPROM -> 326323732
Write 77777 to the EEPROM -> 326323732
Write 77777 to the EEPROM -> 326323732
 means garbage
Code

// Write and Read data to/from an external EEPROM
// My uC: NodeMCU8266
// My EEPROM: FT24C256A

/* EEPROM powered by 8266's 3.3V - 3.2v on the chip
   Write 77777 to the EEPROM
   Read results in this output 326323732 HEX - garbage!
   2 different EEPROMs and 8266's are tested with similar results
   100nF cer. cap directly from VCC to GND on EEPROM chip
*/

/*
  Scanning...
  I2C device found at address 0x50 !
  done
*/

#include <Wire.h>
#define eeprom 0x50 //defines the base address of the EEPROM
int mySDA = 4; // (GPIO04) / D2
int mySCL = 5; // (GPIO05) / D1

void setup()  {
  Wire.begin(mySDA, mySCL);
  Wire.setClock(10000); // Set down to 10000 from default value
  Serial.begin(9600);
}

void loop() {
  delay(1000);
  unsigned int address = 0;
  Serial.println("Write 77777 to the EEPROM");
  for (address = 0; address < 5; address++)
    writeEEPROM(eeprom, address, '7');
  for (address = 0; address < 5; address++) {
    Serial.print(readEEPROM(eeprom, address), HEX);
  }
}

//defines the writeEEPROM function
void writeEEPROM(int deviceaddress, unsigned int eeaddress, byte data ) {
  Wire.beginTransmission(deviceaddress);
  Wire.write((int)(eeaddress >> 8));
  Wire.write((int)(eeaddress & 0xFF));
  Wire.write(data);
  Wire.endTransmission();
}

//defines the readEEPROM function
byte readEEPROM(int deviceaddress, unsigned int eeaddress ) {
  byte rdata = 0xFF;
  Wire.beginTransmission(deviceaddress);
  Wire.write((int)(eeaddress >> 8));
  Wire.write((int)(eeaddress & 0xFF));
  Wire.endTransmission();
  Wire.requestFrom(deviceaddress, 1);
  if (Wire.available())
    rdata = Wire.read();
  return rdata;
}

[gilshultz]

EEPROM does not exist on the ESP8266 however it is generally simulated in external memory. When you have finished writing to it you need to do this: EEPROM.commit(); //Store data to EEPROM. This link will help you.