Does number 8 apply when you're changing the TRIS register, as opposed to the
 actual data register?

-- Mitch


------------------------------
Mitch Miller
mdmiller@nque.com
------------------------------


-----Original Message-----
From:   Steve Baldwin [SMTP:steveb@KCBBS.GEN.NZ]
Sent:   Friday, January 23, 1998 4:20 PM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: I2C Read and Write a byte from EEPROM

> 1)Don't rely on the MC app notes.
> 2)The eeprom manufacturer's data sheets should provide you with all the
> info you need (timing diagrams, etc)
> 3)Be aware of the eeproms write time. (Usually around 10 ms)
> 4)Use the tris registers instead of the port registers to make the pins
> go high and low
> 5)The rest of it is just bit banging.
> 6)Be patient and take it one step (bit) at a time.
> 7)The best advice is to forget i2c unless absolutely neccessary, use SPI
> if you can!

I'd add to that,
8) Remember the read-modify-write thing. Reading another port pin can stuff
up your i2c.
9) Addresses wrap on different boundaries for eeprom read and writes.

Steve.

======================================================
  Very funny Scotty.  Now beam down my clothes.
======================================================
Steve Baldwin                Electronic Product Design
TLA Microsystems Ltd         Microcontroller Specialists
PO Box 15-680                email: steveb@kcbbs.gen.nz
New Lynn, Auckland           ph  +64 9 820-2221
New Zealand                  fax +64 9 820-1929
======================================================

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