The term “I2C Interface” usually refers to means for connecting an I2C bus to a PC. However, there are certainly other I2C interfaces which provide connectivity for this universally used bus to non-PC devices.
Usually this is done via the interface used for almost everything: USB.
A much more reliable, powerful and safe alternative are interfaces which provide their own I2C logic such as Connii MM 2.0 or Tracii XL 2.0. These devices are connected via USB, in addition to being able to operate in multi-master mode they provide a number of important and helpful additional features.
Since they communicate with the PC software on a more efficient level than bit banging, the transfer speed is considerably higher and the load on the PC is much lower.
So what are the considerations when choosing a professional I2C interface?
- An I2C interface should not only consist of wiring to the parallel port of a PC. This approach can cause damage to your PC or notebook and is not very reliable.
- If you intend to use the interface with another I2C master simultaneously, you should opt for a multimaster interface in order to avoid arbitration conflicts on the bus.
- The interface you choose should be capable of running at the same speed as your other I2C devices.
- If you have slaves which are implemented using a microcontroller or if you know that a slave device requires clock stretching, you need to make sure that your interface supports it.
- Choose an interface which has a user interface and programming API which you can easily use and which is supported.
- If possible, a USB interface is preferable over a plug-in card for your PC. This reduces the cable length you need extra on the I2C bus.
- Choose a vendor who offers reliable support and long-term market commitment. As operating systems tend to change from time to time you will need upgrades in order to be able to use such new versions.