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- Py LED Clock
Py LED Clock
A simple clock & temperature application in Python for a 7-segment LED backpack connected to Raspberry Pi.
The app relies on LED libraries from Adafruit, but uses own, slightly modified/extended files.
Initial Configuration
I2C Address
In clock.py change the I2C address to the one you will be using (if it's different than mine: 0x77).
Daylight (sunrise/sunset) Zone
The application dims the display during the night and brightens it while in daylight, so in clock.py change the value of city_name to best correspond to your time zone. See Astral documentation for list of supported cities.
Weather Information
The city temperature is read from forecast.io weather API. For that you need to specify APIKey, LATITUDE and LONGITUDE values in clock.py. To keep the API usage in the free range (so, under 1000 requests/day), the weather info is refreshed only every 2 minutes. Change this if you have a paid forecast.io API license.
Temperature will be displayed in degrees Celsius unless FAHRENHEIT is set to True.
Script Location
Target init system: SysVinit
In led_clock file (the one used for service) change the APP_HOME value to correspond to the directory you have cloned this project into and where clock.py is run from.
Target init system: Systemd
In led_clock.service file (the one used for service) change the path to correspond to the directory you have cloned this project into and where clock.py is run from.
Installation
Setting up LED clock as service
Even though the program can be run directly (from command line), it is of better use if it automatically boots up with the system. To do so, simply install it as a service.
Target init system: SysVinit
sudo cp led_clock /etc/init.d/
sudo chmod +x /etc/init.d/led_clock
sudo update-rc.d led_clock defaults
Target init system: Systemd
sudo cp led_clock.service /lib/systemd/system/
sudo chmod +x /lib/systemd/system/led_clock.service
sudo systemctl enable led_clock
Installing dependencies
The Py LED Clock program uses some 3rd party modules. First prepare the environment (if not already done) for easy module installation:
sudo apt-get install python-pip
sudo apt-get install python-dev
sudo apt-get install python-smbus
Then install the actual modules:
sudo pip install rpi.gpio
sudo pip install requests
sudo pip install astral
sudo pip install pytz
Running
To run the service, execute sudo /etc/init.d/led_clock start. Additionally, the service will run automatically after a reboot.
Notes
Because of display size limitation, both Celsius and Fahrenheit degree symbols for negative temperature values are displayed as 'E' (should be read as 'C -' for Celsius and 'F -' for Fahrenheit).
If you encounter an error like: /etc/init.d/led_clock: 20: /etc/init.d/led_clock: /home/pi/python/led/clock.py: not found, change the line endings Windows --> Unix.
License
Copyright 2015 Robert Šarić
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.