I2C RS485 Chip

[Dave Boland]

A design I was working on was going to use the MAX3140 SPI
<--> RS-485 chip. This is an integrated UART and set of
drivers. The plan has changed and the RS-485 portion moved
to a daughter card. Since all cards will be connected via
I2C, I was looking for a similar chip similar to the 3140,
but with an I2C interface. Can't find any, but perhaps
someone knows of one.

The alternative (and actually a better one in some ways) is
to use a processor with I2C port and a UART port, and
drivers. Problem with this idea is more software needs to
be done (no time) and more board space (not much of that
either).

Help appreciated.

Dave,

 

[PeteS]

You can actually use SPI pins (usually) for I2C. See this page (for
example)

http://www.i2cchip.com/mix_spi_i2c.html

I would also check the datasheet on whatever you are sourcing the SPI
from, as it may support I2C directly (with a little register tweaking).

Cheers

PeteS


Dave Boland wrote:

A design I was working on was going to use the MAX3140 SPI
--> RS-485 chip. This is an integrated UART and set of
drivers. The plan has changed and the RS-485 portion moved
to a daughter card. Since all cards will be connected via
I2C, I was looking for a similar chip similar to the 3140,
but with an I2C interface. Can't find any, but perhaps
someone knows of one.

The alternative (and actually a better one in some ways) is
to use a processor with I2C port and a UART port, and
drivers. Problem with this idea is more software needs to
be done (no time) and more board space (not much of that
either).

Help appreciated.

Dave,