I2C clock frequency?

[Qacer]

Thanks!

Would serial communication with a 400KHz I2C device still work if my PIC oscillator setting is at 4MHz?

[mister_e]

of course yes, if not we should all use 400KHZ or less as oscillator. PBP generate the right clock frequency for you. Look in the manual in the I2CREAD/I2CWRITE

[Qacer]

By the way, I wanted to use the internal 4MHz oscillator. From what I heard, that the frequency of oscillation might not be as stable. Would I2C communications still work if I go this route?

[mister_e]

Unstable yes and no. At least, i would never trust too much a serial communication RS232 or else running with any internal or ceramic resonator. Worst if the final product maybe use in various ambient temperature.

For I2C... i never got issue even by running internal OSC... well as now

[Qacer]

Thanks, mister_e!

Actually, I just want to use a PIC to communicate to one single I2C device. I won't have any external serial communication via a computer or something similar.

I wanted to make my circuit very small, so I wanted to get rid of any components that are not too crucial. My main concern is that if I don't use a crystal then I wouldn't be able to communicate accurately with the I2C device.

But that is good to hear that you haven't had any problems using the internal oscillator with the I2C device.