smbus2.py 文件源码

def write_i2c_block_data(self, i2c_addr, register, data):
        # type: (int, int, list) -> None
        """
        Write a block of byte data to a given register
        :param i2c_addr: i2c address
        :param register: Start register
        :param data: List of bytes
        """
        length = len(data)
        if length > I2C_SMBUS_BLOCK_MAX:
            raise ValueError("Data length cannot exceed %d bytes" % I2C_SMBUS_BLOCK_MAX)
        self._set_address(i2c_addr)
        msg = i2c_smbus_ioctl_data.create(
            read_write=I2C_SMBUS_WRITE, command=register, size=I2C_SMBUS_I2C_BLOCK_DATA
        )
        msg.data.contents.block[0] = length
        msg.data.contents.block[1:length + 1] = data
        ioctl(self.fd, I2C_SMBUS, msg)