Arduino - Wire

Arduino

Buy | Download | Getting Started | Learning | Reference | Hardware | FAQ

Blog » | Forum » | Playground »

Reference Language (extended) | Libraries | Comparison | Board

## Wire Library

This library allows you to communicate with I2C / TWI devices. On the Arduino, SDA (data line) is on analog input pin 4, and SCL (clock line) is on analog input pin 5.

#### Functions

- begin()
- begin(address)
- requestFrom(address, count)
- beginTransmission(address)
- endTransmission()
- send()
- byte available()
- byte receive()
- onReceive(handler)
- onRequest(handler)

#### Note

There are both 7- and 8-bit versions of I2C addresses. 7 bits identify the device, and the eighth bit determines if it's being written to or read from. The Wire library uses 7 bit addresses throughout. If you have a datasheet or sample code that uses 8 bit address, you'll want to drop the low bit (i.e. shift the value one bit to the right), yielding an address between 0 and 127.

Reference Home

Corrections, suggestions, and new documentation should be posted to the Forum.

The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.

Edit Page | Page History | Printable View | All Recent Site Changes