Re: I2C trick?


"larwe" <zwsdotcom@xxxxxxxxx> wrote in message
news:5980266c-d5ab-42e2-8cd5-609ba19d84f9@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Dec 28, 11:27 am, Vladimir Vassilevsky <antispam_bo...@xxxxxxxxxxx>
wrote:

Anything from just not working to a total bus lockup, (if devices
detect a START but not a STOP.)

Would you describe a scenario which can lead to an unrecoverable problem?

If both slaves go on-bus in output mode then both SCL and SDA lines
are being driven hard by the slaves; how is the master going to create
edges?

Hi Larwe,

Thank you for the meaningful response.
The I2C bus is supposed to ignore the incorrect sequences on the bus; so I
don't see a problem there. What you mentioned is possible only if the
hardware is broken.


I can imagine you could do very funky things with voltage dividers to
ensure that the master could always assert its will over both I/Os
regardless of what the other end is trying to do, but this would
result in some horrible non-spec I2C implementation. I can't imagine
shipping such a hack.

There should not be a need for such complication. So far nobody suggested a
valid reason why exactly it is a bad idea to swap the SCL and SDA to
separate the I2C slaves. I tried to do that; everything worked like
expected. This could actually be a good trick.

VLV


.

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