View Full Version : Expanding BSII I/O Ways and recommendations.

02-09-2010, 10:17 PM
During a Google search, I·came across·something·called an I2C device in which you are able to expand inputs and outputs on a BSII module.· However, I would like to ask if there are any other ways to expand inputs and outputs on a BSII module???· Thanks in advance.

02-09-2010, 10:50 PM
Look at "serial-in/parallel out" and "parallel in/serial out" shift registers. They give you the I/O expansion without the headaches of I2C. The drawback is that you need separate chip selects for each chip, but even this can be overcome with a 74HC138 (3-to-8) or 74HC139 (dual 2-to-4) chip.


Mike Green
02-09-2010, 11:24 PM
There are several Nuts and Volts Columns on this subject. Browse the index. Go to the main Parallax webpage and click on the Resources tab. You'll see a link to the Nuts and Volts Columns index.

The BS2 doesn't have built-in support for the I2C protocol. You can still use it and one of the columns has sample code for doing so, but it takes a bit of code to do this. The BS2p series of Stamps have built-in statements for I2C and other columns discuss this.