#include "wire_i2c.h"
WireI2C I2C( I2C_NUM_1, 400000 );
...
I2C.begin();
...
I2C.beginTransmission( 0x3C ); // device address
I2C.write(0x80); // send some data
I2C.write(0x00); // send some data
I2C.endTransmission();
...
I2C.end();