The I2C (Inter-Integrated Circuit) bus was designed by Philips in the early '80s to allow easy
communication between components which reside on the same circuit board. TWI stands
for Two Wire Interface and for most marts this bus is identical to I²C. The name TWI was
introduced by Atmel and other companies to avoid conflicts with trademark issues related to
I2C bus consists of two wires, SDA (Serial Data Line) and SCL (Serial Clock Line). Ardu-
ino Yún has I2C/TWI on Digital 2 (SDA) and Digital 3 (SCL).
For testing, I used PCF8591 AD/DA Converter module with sensor and actuator devices.
You can find it on the following online store:
• eBay, http://www.ebay.com
• Aliexpress, http://www.aliexpress.com/
In addition, you can find this device on your local electronics store/online store.