I2C
Code Example
from periphery import I2C
# Open i2c-0 controller
i2c = I2C("/dev/i2c-0")
# Read byte at address 0x100 of EEPROM at 0x50
msgs = [I2C.Message([0x01, 0x00]), I2C.Message([0x00], read=True)]
i2c.transfer(0x50, msgs)
print("0x100: 0x{:02x}".format(msgs[1].data[0]))
i2c.close()
API
- class periphery.I2C(devpath)[source]
Bases:
object
Instantiate an I2C object and open the i2c-dev device at the specified path.
- Parameters:
devpath (str) – i2c-dev device path.
- Returns:
I2C object.
- Return type:
- Raises:
I2CError – if an I/O or OS error occurs.
- transfer(address, messages)[source]
Transfer messages to the specified I2C address. Modifies the messages array with the results of any read transactions.
- Parameters:
address (int) – I2C address.
messages (list) – list of I2C.Message messages.
- Raises:
I2CError – if an I/O or OS error occurs.
TypeError – if messages type is not list.
ValueError – if messages length is zero, or if message data is not valid bytes.
- property fd
Get the file descriptor of the underlying i2c-dev device.
- Type:
int
- property devpath
Get the device path of the underlying i2c-dev device.
- Type:
str
- class Message(data, read=False, flags=0)[source]
Bases:
object
Instantiate an I2C Message object.
- Parameters:
data (bytes, bytearray, list) – a byte array or list of 8-bit integers to write.
read (bool) – specify this as a read message, where data serves as placeholder bytes for the read.
flags (int) – additional i2c-dev flags for this message.
- Returns:
Message object.
- Return type:
- Raises:
TypeError – if data, read, or flags types are invalid.