Clock speed for I2C External EEPROM?


I am about to place an order and it occurred to me that I need to select the correct clock speed of the chip.

Microchip 24LC256-I/P in either 0.4, 1 or 10Mhz

Which one is correct?


I2C normally only goes up to 400kHz, I believe. Looks like the 24FC256 goes up to 1MHz (or 400kHz at lower voltages); I don't see any sign that there is a 10MHz version...

So a 400khz one is cool to order?

So a 400khz one is cool to order?

Yes. The Arduino operates at 100kHz. You can hack the Library-sources so it works at 400kHz. 1MHz is not possible with the Arduino hardware. Eberhard