hop of those help? The String class handles a char array buffer allocated in heap memory. The object of class String only has a pointer to this buffer. If you store a String object to EEPROM, you don't store the buffer and after retrieving the object the pointer is not valid. Use C strings (zero terminated character arrays) of predefined size to store a struct with string in EEPROM.
may help you . Should is not the appropriate word, I would suggest to use the UART (Serial.print() and Serial.read()). Because the ESP has an operating voltage of 3.3V and Arduino 5V, you must use a level shifter.
Arduino BLE Project (esp32)
By : user3676663
Date : March 29 2020, 07:55 AM
wish help you to fix your issue I want to make a device project that perform to receive data(device id) continuously from another four BLE(esp32 module). Can I do this by using one Arduino with one esp32 module? or needs 4 module to receive data from 4 individual device? There will also have 4 led for 4 device, if any device go out of range corresponding led turn off and if get signal led turn on. , A BLE device can have multiple connections, so one should be fine.
esp32 EEPROM read/write cycle
By : d呵呵
Date : August 28 2020, 04:00 PM
will help you The ESP32 doesn’t have an actual EEPROM; instead it uses some of its flash storage to mimic an EEPROM. The specs will depend on the specific SPI flash chip, but they’re likely to be closer to 10,000 cycles than 100,000. Writing to it every couple of seconds will likely wear it out pretty quickly - it’s not a good design choice, especially if you keep rewriting the same location.