Setup

This howto is designed to help using the Arduino code

To download it:

git clone --recursive https://github.com/TakkTile/takktile_arduino.git

Fast I2C Communication

(from here: http://arduino.cc/forum/index.php/topic,16793.0.html)

the atmega-hardware can do 400 KHz, but you have to tweak the Wire-library in file hardware/libraries/Wire/utility/twi.h.

Near the top of the file you see :

#ifndef TWI_FREQ

#define TWI_FREQ 100000L

#endif

If you change that to:

#ifndef TWI_FREQ

#define TWI_FREQ 400000L

#endif

The I²C bus should run at 400kHz

But you also have to the delete the files

hardware/libraries/Wire/Wire.o

hardware/libraries/Wire/utility/twi.o

This will force the compiler to recompile these files.