* These two functions help us write to the 24LC256 EEPROM chip */ #define EEPROM_ADDR 0x50 void EEPROM_write(unsigned int addr,byte data) Thats about it really. this is the address of the chip on the i2c bus (you can connect more than one i2c thingies on an i2c bus and select which one you want to talk to by changing the address). The output pins are SCL, SDA and GND for each port Wire (pins 20 and 21) and Wire 1 (pins 70 and 71), presented as JST. The resulting shield is stackable, so can be reused in multiple projects. It probably is an ok starting point for the revisions you have in mind. This was a simple build to solve a recurring need to use both I2C ports and both ports to be level shifted to 5V (e.g., for interfaces to Arduino UNO). Note there is a macro definition of 0x50. at 5:44 dsscircuits' Arduino I2C master library webpage shows five revisions of the I2C library that your github link is for.

ArduinoESP32OTA : Firmware update for ESP32.

Firstly, include the Wire library headers somewhere near the top of your sketch: /* Use 24LC256 EEPROM to save settings */ #include Then add some functions to read and write bytes from the EEPROM (I only care about individual bytes but there is a page write feature in the chip too). ArduinoConnectionHandler : Arduino Library for network connection management (WiFi, GSM, NB, Ethernet) ArduinoDebugUtils : Debugging module with different debug levels, timestamps and printf-style output. Here are some snippets of code that I use in my sketches.

Arduino due wire library update