Forums / ARM Development / I2C Registers - Rickey's World of Microcontrollers & Microprocessors

Discussion in "ARM Development" started by nari Mar 6, 2009.

nari

[ Fresher ]

Fri Mar 06 2009, 04:47 pm

Hay
I need Program help
I have interfaced 6 toggle switches with LPC2114 (In built I2C) using PCF8574A PORT expander by connecting SDA, SCL pins.I completed hard ware part but I am facing problem with software. I Read LPC2114 data sheet but I am unable to understand the concept of How to write the program using I2C Registers.
Please help me how to write program to communicate LPC2114 I2C with PCF8574A PORT expander
Thank you

Regards
naresh

shyam

[ Enthusiast ]

Fri Mar 06 2009, 05:09 pm

have you started yet?

get hold of a lpc21xx user manual, that will solve most of the problem.

nari

[ Fresher ]

Fri Mar 06 2009, 06:20 pm

Hay
I read the user manual, but I just confuse with I2C Status Register (I2STAT). In the Register the least three bits are always 0. The remain bits give 25 status codes correspond to defined I2C states. How to write the program by using these states.

Regards
naresh

ajay_bhargav

Site Owner

Mon Mar 09 2009, 04:40 pm

according to datasheet refer to table 3 and table 6 of this document
http://www.nxp.com/acrobat_download/various/8XC552_562OVERVIEW_2.pdf

to know about all the 25 status codes of I2STAT register. Just go through it. collectively they make a state machine.