Python - RGB LED Bricklet

This is the description of the Python API bindings for the RGB LED Bricklet. General information and technical specifications for the RGB LED 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).

Simple

Download (example_simple.py)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your RGB LED Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_rgb_led import BrickletRGBLED

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

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

    # Set light blue color
    rl.set_rgb_value(0, 170, 234)

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

Rainbow

Download (example_rainbow.py)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "zHN" # Change to your UID

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_rgb_led import BrickletRGBLED

import colorsys
import time

SECONDS_PER_ROUND = 1.5
COLORS_PER_ROUND = 256

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

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

    print("Press ctrl+c to exit")

    while True:
        for i in range(COLORS_PER_ROUND):
            r, g, b = colorsys.hsv_to_rgb(1.0*i/COLORS_PER_ROUND, 1, 0.1) # Calculate color
            rl.set_rgb_value(int(r*255), int(g*255), int(b*255)) # Set color

            time.sleep(SECONDS_PER_ROUND/COLORS_PER_ROUND) # Wait for next color change

    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.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

All methods listed below are thread-safe.

Basic Functions

BrickletRGBLED(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

rgb_led = BrickletRGBLED("YOUR_DEVICE_UID", ipcon)

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

BrickletRGBLED.set_rgb_value(r, g, b)
Parameters:
  • r -- int
  • g -- int
  • b -- int
Return type:

None

Sets the rgb value for the LED. The value can be between 0 and 255.

BrickletRGBLED.get_rgb_value()
Return type:(int, int, int)

Returns the rgb value of the LED as set by set_rgb_value().

The returned namedtuple has the variables r, g and b.

Advanced Functions

BrickletRGBLED.get_api_version()
Return type:[int, int, int]

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.

BrickletRGBLED.get_response_expected(function_id)
Parameters:function_id -- int
Return 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.

See set_response_expected() for the list of function ID constants available for this function.

BrickletRGBLED.set_response_expected(function_id, response_expected)
Parameters:
  • function_id -- int
  • response_expected -- bool
Return type:

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 function ID constants are available for this function:

  • BrickletRGBLED.FUNCTION_SET_RGB_VALUE = 1
BrickletRGBLED.set_response_expected_all(response_expected)
Parameters:response_expected -- bool
Return type:None

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

BrickletRGBLED.get_identity()
Return type:(str, str, chr, [int, int, int], [int, int, int], int)

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.

The returned namedtuple has the variables uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Constants

BrickletRGBLED.DEVICE_IDENTIFIER

This constant is used to identify a RGB LED Bricklet.

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

BrickletRGBLED.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a RGB LED Bricklet.