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How many i2c buses can I use with new RaspberryPi 2 B model?

Posted: Tue Jun 16, 2015 2:54 pm
by alvaro36horas
I am not sure if the second i2C bus (pin 27 BCM0: ID_SD and pin 28 BCM1: ID_SC) is only for use with i2c EEPROM for configuration purposes.
Thank you.

Re: How many i2c buses can I use with new RaspberryPi 2 B mo

Posted: Tue Jun 16, 2015 3:37 pm
by joan
It is not intended for general use. Nothing prevents you from using it at the moment though. I don't know if such use will be compromised by a future update

Re: How many i2c buses can I use with new RaspberryPi 2 B mo

Posted: Tue Jun 16, 2015 7:57 pm
by 6by9
There's no real reason why it can't be used as long as you don't want to use the camera module - that uses the I2C-0 peripheral direct from the GPU, and there is no arbitration between the two processors.
Memory says that there are no pullups fitted to those pins, so you may need to fit your own.

Re: How many i2c buses can I use with new RaspberryPi 2 B mo

Posted: Wed Jun 17, 2015 8:55 am
by alvaro36horas
I understand 6by9. ;)
Thanks 6by9 and Joan, yours answers were very useful.
Best regards,
Álvaro

Re: How many i2c buses can I use with new RaspberryPi 2 B mo

Posted: Sat Jun 27, 2015 5:42 am
by Richard-TX
I use both buses all the time. Works great.

Re: How many i2c buses can I use with new RaspberryPi 2 B mo

Posted: Sat Jun 27, 2015 8:05 am
by joan
Of course it is also possiible to bit-bang I2C on any pair of spare gpios.

Bit-bang does allow for repeated starts and clock stretching.

My offering.