PyGlow

PyGlow is a small Python module for the PiGlow addon by Pimoroni which will let you flex the LED muscles of this fantastic addon. It was started as PiGlow by Jason (@Boeeerb) but I (@ben_leb) decided to fork it to provide a more clean and easier to use module.

Features

• Control a single LED, a single arm, a single color or any combination of these
• Pulsing LED
• Gamma Correction (makes the progression from 0-255 more visually linear)

Installation instructions

Preparation

For instructions on how to setup Raspberry Pi for use with PyGlow, please see https://github.com/pimoroni/piglow#setting-up-your-raspberry-pi

Requirements

PyGlow module requires the smbus Python module. It must be installed before the PyGlow module is used. Example of installation for RASPBIAN:

sudo apt-get install python-smbus

Downloading and testing the PyGlow module

Now create a directory for python modules and then change to that directory:

$ mkdir -p ~/lib/python/
$ cd ~/lib/python/

Next get the latest version of PyGlow python module:

git clone https://github.com/benleb/PyGlow.git

This will download the PyGlow module into the ~/lib/python/PyGlow directory.

In order to make the PyGlow module accessible for other scripts, a system environment variable with a path to the module must be exported (you can add it into your ~/.bashrc):

export PYTHONPATH=$PYTHONPATH:~/lib/python

Now go to the examples directory and run the testing script:

cd ~/lib/python/PyGlow/examples/
python test.py

If the script loads, you can set the brightness of each LED color group by typing a number between 0 (off) and 255 (brightest).

See the other files in the examples directory for more examples of how to use PyGlow.

Install using pip

If you just want to install the PyGlow library for use in your own project, you can also install it using pip

$ pip install git+https://github.com/benleb/PyGlow.git

The PyGlow.py files will be downloaded and placed in the site-packages directory ready for use.

Usage

Instantiation

In order to be able to use PyGlow module, the PyGlow() class must be imported:

from PyGlow import PyGlow

Then it's possible to instantiate the PyGlow() object:

pyglow = PyGlow()

The PyGlow() object can accept four optional parameters:

• brightness=None - sets default brightness level (value: number from 0 and 255)
• speed=None - sets default pulsing speed in milliseconds (value: number > 0)
• pulse=None - enables pulsing by default (value: True or False)
• pulse_dir=None - sets default pulsation direction (value: UP, DOWN, BOTH)

The default parameter values are used across all functions unless overridden on the function level. If the default parameter value is not set during the object instantiation, it must be set on the function level. The value for the parameter speed and pulse_dir must be set only if the parameter pulse=True.

Functions

Functions provided by the PyGlow() object are:

led(led, brightness=None, speed=None, pulse=None, pulse_dir=None)

Sets the specific led to the brightness level. The led is in the range of 1 to 18. The led parameter can also be a list of individual leds. The other parameters can have the same value like in the case of the object instantiation.

color(color, brightness=None, speed=None, pulse=None, pulse_dir=None)

Sets the specific color group to the brightness level. The color group can be either a number or a name:

• 1 = white
• 2 = blue
• 3 = green
• 4 = yellow
• 5 = orange
• 6 = red

The other parameters can have the same value like in the case of the object instantiation.

arm(arm, brightness=None, speed=None, pulse=None, pulse_dir=None)

Sets the specific LED arm to the brightness level. The arm value can be either 1, 2 or 3. The other parameters can have the same value like in the case of the object instantiation.

all(brightness=None, speed=None, pulse=None, pulse_dir=None)

Sets all LEDs to the brightness level. The parameters can have the same value like in the case of the object instantiation.

set_leds(leds, brightness=None, speed=None, pulse=None, pulse_dir=None)

Prepares the list of leds to be set to the brightness level. The leds list can be composed of numbers from 1 to 18 or connection of color name and arm number (e.g. red1 will light up the red LED in the arm 1). The other parameters can have the same value like in the case of the object instantiation. The set brightness will take effect only after the update_leds() is called (see bellow).

update_leds()

Sets the brightness level of all LEDs specified by the set_leds() function.

leds_odd = [1, 3, 5, 7, 9, 11, 13, 15, 17]
leds_even = [2, 4, 6, 8, 10, 12, 14, 16, 18]
pyglow.set_leds(leds_odd, 150)
pyglow.set_leds(leds_even, 10)
pyglow.update_leds()

Files

• pyglow.py - Python module providing the PyGlow class
• examples/bin_clock.py - binary clock by Jiri Tyr
• examples/clock.py - binary clock by Jason (@Boeeerb)
• examples/cpu.py - CPU percentage indicator by Jason (@Boeeerb)
• examples/pulsetest.py - shows how to use LED pulsing
• examples/set_leds.py - shows how set_leds() and update_leds() works
• examples/test.py - allows to choose the brightness of each LED color group

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

This module is release under the MIT license.