This library currently only supports the arduino DUE hardware TWI interface

Including this library

When including this library, add these lines to your module's Makefile.due:

#add I2C_library
I2C               ?= ../../../libraries/I2C_library
include              $(I2C)/Makefile.inc

Then you'll be able to include the library like so in your project files:

#include <i2c_bus.hpp>

Using the library

Instantiate the library like so:

auto bus = r2d2::i2c::i2c_bus_c(r2d2::i2c::i2c_bus_c::interface::interface_0, 50000);

You can replace r2d2::i2c::i2c_bus_c::interface::interface_0 with r2d2::i2c::i2c_bus_c::interface::interface_1 if you need to use the secondary interface.

IMPORTANT: while it might seem confusing, the I2C library uses the names as used in the datasheet. This means that if you want to use the scl and sda pins as printed on the DUE, you have to use i2c_bus_c::interface::interface_1 and if you wish to use scl1 and sda1 as printed on the DUE, you have to use i2c_bus_c::interface::interface_0.

Once instantiated you can use the read or the write function like so:

bus.write(address, data, sizeof(data) / sizeof(uint8_t));
bus.read(address, data, n);

Where data is your data array and address is your 7-bit device address (i.e. 0x3C for an OLED display)

In the read example, data is your buffer and n is the amount of bytes you want to read.

Using Repeated Start or Internal Address

Should you have a device that uses repeated start or an internal address, you need to modify your read/write calls.

To use it, you just have to add the internal address and the size in bytes to the read/write calls, like so:

bus.read(address, data, n, internal_address, 2);

where internal_address is the address (maximum size is 3 bytes) and 2 means that the value of internal_address takes up two bytes.

Class Diagram