18.8.1.3.1 Code

Add to user application main():

while (true) {
    /* Wait for direction from master */
    dir = i2c_slave_get_direction_wait(&i2c_slave_instance);

    /* Transfer packet in direction requested by master */
    if (dir == I2C_SLAVE_DIRECTION_READ) {
        packet.data = read_buffer;
        i2c_slave_read_packet_wait(&i2c_slave_instance, &packet);
    } else if (dir == I2C_SLAVE_DIRECTION_WRITE) {
        packet.data = write_buffer;
        i2c_slave_write_packet_wait(&i2c_slave_instance, &packet);
    }
}