2nd I2C port

I want to a 2nd I2C port Is there a way to use the

2nd I2C port on Pin 69, 70

The I2C bus can have multiple slaves. You need to ensure that each has an unique ID.

Could this be better than using a 2nd I2C pheripheral function ?

You could also use a software I2C, if speed doesn’t matter too much !


Is it possible to use that 2nd I2C port?

It can have it’s use when a device has a fixed I2C address and you need to use more then 1.

(Software I2C might be an option yes, but why use if there is a 2nd port available)

To my knowledge, USBizi boards only have 1 hardware I2C port… See here http://www.ghielectronics.com/catalog/product/256/ for an example.

True, but the LPC2387 has three of em. Could those be made available? :slight_smile:

What Fez board are you using?

Do yo have an example application on where you need 3?

I have an example where two would be very useful.

We have remote I2C devices using range extenders. The first version of this device had a fixed I2C address, so only one could be used. A newer version has a flexible I2C address, but this needs to be configured manually. We want to use two devices and need to address these devices by hand before they can ship to customers.

If we have 2 busses, we don’t need to configure any of the devices, they both reside on their own bus. This saves a lot of time.

Three is not need (for us) but two would be sweet.

We provide software I2C. Use it on as many pins as you need.

nod But two hardware ports would be sweeter :slight_smile:

How does the Software I2C perform? 100 khz?

I think it is about 100Khz.