Lpc2114

[chandu13]

Hay
I need 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
Chandu

 

[3v0]

It could be that no one here has used these chips.

Have you read TN06005_LPC2000_I2C and looked for other I2C info in the Download All Documentation link on this page.

 

[Ubergeek63]

one question: why?

the LPC2114 has plenty of pins that you could just bring the toggle switches into, with proper protection of course.

Dan

 

[chandu13]

Pcf8574

Hay

I interfaced LPC2114 with PCF8574.
From the data sheet The I/Os should be HIGH before being used as inputs.
How to make PCF8574 as the Input port to read the external inputs.
LPC2114 other pins I used for other applications,

Regards
Chandu

 

[Ubergeek63]

Hay

I interfaced LPC2114 with PCF8574.
From the data sheet The I/Os should be HIGH before being used as inputs.
How to make PCF8574 as the Input port to read the external inputs.
LPC2114 other pins I used for other applications,

Regards
Chandu

then why not use a bigger part like a LPC2361FBD100 100 pinner at $7 instead of a LPC2114 64 pinner at $10 AND a PCF8574 at $1.50? (rounded off digikey single piece prices)

Dan

 

[chandu13]

Lpc2361

In the KeiluVision3 Complier LPC2361 Device is not available

Regards
chandu

 

[Ubergeek63]

it should be and even if it is not it is very close to many of the LPC23xx family and not that far off of many of the others. For your purposes you should be able to compile for a different chip and still have it run fine as long as you do not want to run one of the peripherals they do not have the support for.

Pick the highest one they have support for and compare register locations, I think you will be pleasantly surprised. NXP tends to use the same location and hardware for all the ones in the same family at least and in most cases across the entire ARM line.

Dan