View Full Version : I2C usage (and other capabilities - advantages) on a BS2px

T&E Engineer
01-06-2006, 04:02 AM
Now that I have both a BS2 and BS2px (and SX28)...I want to learn more about the BS2px's capabilities besides just the speed factor. I know that it has built in LCD functions but that is only for parallel versions of LCD (and I have a 2x16 non backlit parallel LCD, 2x16 backlit serial LCD and 4x20 backlit serial LCD). I don't think I will use parallel if serial has so many more benefits to it.

In particular, the I2C capabilites in the BS2px on what it is, why it is to be used vs other conventional methods on the BS2, etc..

I have the BS2p downloaded book but wondering if there was any other or better resources to look at.


Timothy Gilmore

joe from NY
01-06-2006, 04:18 AM
Wow, great post to read. Hope to see some good answers...Been wondering what the·I2C bus was·for...·Ive been wanting to order a BS2 and i have put off buying a BS2P because of differences ive seen with TIMING? (Not that its broken, just different)..

PJ Allen
01-06-2006, 04:23 AM
Here's the I2C-Bus Specification, from the inventors:


T&E Engineer
01-06-2006, 04:26 AM
Thanks PJ Allen!

This should be good weekend reading material.

Timothy Gilmore

joe from NY
01-06-2006, 04:27 AM
From what ive read ( and hear is a start for some info on the I2C http://www.esacademy.com/faq/i2c/general/i2cproto.htm·) I2C is to simplify communication between devices (MASTER and MULTIPLE SLAVES.

One example-

Say if you have an EEPROM hooked up to a BS2P. Suppose you have a BS2 stamp (master device)·that is measuring temperature via inputs, and it needs to store the values (in a EEPROM). It could communicate with·the EEPROM (slave)·with the I2C bus , and the BS2P programming is simplified using I2C commands..

Perhaps someone has some other examples?

Jon Williams
01-06-2006, 05:11 AM
The I2C capabilities of the BS2p family are thoroughly documented in our manual. You can download a PDF from www.parallax.com. In short, the BASIC Stamp acts as the I2C Master and uses 7-bit addressing (I've never seen an I2C component that doesn't use this addressing, even though the spec accommodates other schemes). The only caveat is the pin connections: 0/1 or 8/9. Other than that, it's pretty doggone easy and I use I2C components quite frequently in my projects.

Jon Williams
Applications Engineer, Parallax

T&E Engineer
01-06-2006, 06:46 AM
Thank you Jon!

I appreciate your insight on this. I will read through the manual again over the weekend.

Timothy Gilmore

Loopy Byteloose
01-06-2006, 03:50 PM
Having looked many different places, the PBasic Manual has the best explanation of I2C, One-wire, and SPI ANYWHERE.

Additionally if you are not into C or Assembly, it is a much easier entry point.· I strongly suggest you read it first BEFORE trying to master manufacturer's PDFs.·

"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

·················································· ···················· Warm regards,····· G. Herzog [·黃鶴 ]·in Taiwan