Python - Piezo Buzzer Bricklet

This is the description of the Python API bindings for the Piezo Buzzer Bricklet. General information and technical specifications for the Piezo Buzzer Bricklet are summarized in its hardware description.

An installation guide for the Python API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Beep

Download (example_beep.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Piezo Buzzer Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_piezo_buzzer import BrickletPiezoBuzzer

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    pb = BrickletPiezoBuzzer(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Make 2 second beep
    pb.beep(2000)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Morse Code

Download (example_morse_code.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your Piezo Buzzer Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_piezo_buzzer import BrickletPiezoBuzzer

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    pb = BrickletPiezoBuzzer(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Morse SOS
    pb.morse_code("... --- ...")

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

API

Generally, every method of the Python bindings can throw an tinkerforge.ip_connection.Error exception that has a value and a description property. value can have different values:

  • Error.TIMEOUT = -1
  • Error.NOT_ADDED = -6 (unused since Python bindings version 2.0.0)
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12
  • Error.INVALID_UID = -13
  • Error.NON_ASCII_CHAR_IN_SECRET = -14

All methods listed below are thread-safe.

Basic Functions

BrickletPiezoBuzzer(uid, ipcon)
Parameters:
  • uid – Type: str
  • ipcon – Type: IPConnection
Returns:
  • piezo_buzzer – Type: BrickletPiezoBuzzer

Creates an object with the unique device ID uid:

piezo_buzzer = BrickletPiezoBuzzer("YOUR_DEVICE_UID", ipcon)

This object can then be used after the IP Connection is connected (see examples above).

BrickletPiezoBuzzer.beep(duration)
Parameters:
  • duration – Type: int, Unit: 1 ms, Range: [0 to 232 - 1]
Returns:
  • None

Beeps for the given duration.

BrickletPiezoBuzzer.morse_code(morse)
Parameters:
  • morse – Type: str, Length: up to 60
Returns:
  • None

Sets morse code that will be played by the piezo buzzer. The morse code is given as a string consisting of "." (dot), "-" (minus) and " " (space) for dits, dahs and pauses. Every other character is ignored.

For example: If you set the string "...---...", the piezo buzzer will beep nine times with the durations "short short short long long long short short short".

Advanced Functions

BrickletPiezoBuzzer.get_api_version()
Returns:
  • api_version – Type: [int, ...], Length: 3, Range: [0 to 255]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletPiezoBuzzer.get_response_expected(function_id)
Parameters:
  • function_id – Type: int, Range: See constants
Returns:
  • response_expected – Type: bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

  • BrickletPiezoBuzzer.FUNCTION_BEEP = 1
  • BrickletPiezoBuzzer.FUNCTION_MORSE_CODE = 2
BrickletPiezoBuzzer.set_response_expected(function_id, response_expected)
Parameters:
  • function_id – Type: int, Range: See constants
  • response_expected – Type: bool
Returns:
  • None

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

  • BrickletPiezoBuzzer.FUNCTION_BEEP = 1
  • BrickletPiezoBuzzer.FUNCTION_MORSE_CODE = 2
BrickletPiezoBuzzer.set_response_expected_all(response_expected)
Parameters:
  • response_expected – Type: bool
Returns:
  • None

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletPiezoBuzzer.get_identity()
Return Object:
  • uid – Type: str, Length: up to 8
  • connected_uid – Type: str, Length: up to 8
  • position – Type: chr
  • hardware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • firmware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • device_identifier – Type: int, Range: [0 to 216 - 1]

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

BrickletPiezoBuzzer.register_callback(callback_id, function)
Parameters:
  • callback_id – Type: int
  • function – Type: callable
Returns:
  • None

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

def my_callback(param):
    print(param)

piezo_buzzer.register_callback(BrickletPiezoBuzzer.CALLBACK_EXAMPLE, my_callback)

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickletPiezoBuzzer.CALLBACK_BEEP_FINISHED
Callback Parameters:
  • no parameters

This callback is triggered if a beep set by beep() is finished

BrickletPiezoBuzzer.CALLBACK_MORSE_CODE_FINISHED
Callback Parameters:
  • no parameters

This callback is triggered if the playback of the morse code set by morse_code() is finished.

Constants

BrickletPiezoBuzzer.DEVICE_IDENTIFIER

This constant is used to identify a Piezo Buzzer Bricklet.

The get_identity() function and the IPConnection.CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletPiezoBuzzer.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Piezo Buzzer Bricklet.