OK, if you read the datasheet, you will see VIH = 2v2 and VIL = 0v8, which means the I2C signals are compatible with a 3v3 pullups. The module you referenced has pullup resistors to 5v0, which means they must be removed. There are voltage convertors from TI for I2C devices, but in this case they are not required. However, if you want to leave the 5v0 pullup resistors on the module, then you must use one of these voltage translators. Here is an example:
https://www.sparkfun.com/products/11955 <https://www.sparkfun.com/products/11955> Regards, John > On Jul 26, 2017, at 3:14 PM, William B <wbbena...@gmail.com> wrote: > > John, I get it. But I do not know how it would be possible to do this in my > DS1307 module which is of this type: > http://www.ebay.com/itm/5-PCS-I2C-RTC-DS1307-AT24C32-Real-Time-Clock-Module-For-AVR-ARM-PIC-/172308340060?epid=846722400&hash=item281e609d5c:g:VxcAAOSwawpXsn0J > > <http://www.ebay.com/itm/5-PCS-I2C-RTC-DS1307-AT24C32-Real-Time-Clock-Module-For-AVR-ARM-PIC-/172308340060?epid=846722400&hash=item281e609d5c:g:VxcAAOSwawpXsn0J> > > > How would It connect to 3.3V hardware instead of 5V? > > Thank you again! > > > > > > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com > <mailto:beagleboard+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/2b99797f-afbb-4408-a47d-3efcbf10b0d4%40googlegroups.com > > <https://groups.google.com/d/msgid/beagleboard/2b99797f-afbb-4408-a47d-3efcbf10b0d4%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/172B3109-D6D8-4358-8133-6F8635C520CC%40gmail.com. For more options, visit https://groups.google.com/d/optout.
