love-box

• A remotely controllable e-paper display using waveshare's 7.5" e-paper display, a Raspberry Pi Zero W, and Firebase's free-tier real-time database
• A gift meant for leaving meaningful notes/messages for someone you love

Repository Structure

/Api

• Contains a simple flask API to serve requests for updating the message/picture for the display
• message.py serves as a class representing the database objects
• message_repository.py serves as a repository for fetching and updating database values
• api.py serves requests for updating or previewing messages/images from the UI (in the following section)

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/LoveBoxUi

• Contains a React application for easily changing the display picture
• The look:
• Or on mobile:

• The UI allows:
  • Viewing the picture gallery, choose a picture and upload. Pictures are shuffled by default and can be reshuffled
  • Selecting a font size and uploading a message (send button used for uploading)
  • Selecting a font size and previewing where line breaks will be in message (with left preview button)

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/RpiUpdateService

• Update service hosted on the raspberry Pi Zero W which controls the display
• Python script which is run every 10 minutes to check database contents and update display accordingly
• Script is called using a cronjob

/ShellScripts

• auto_update.sh
  • Called every 24 hours using a cronjob to update raspberry pi with remote code
• update_display.sh
  • Called every 10 minutes using a cronjob to update the display with database contents
• install.sh
  • Installs needed dependencies for the raspberry pi

/src

• update_display.py updates the display itself with the contents within the database
  • The time stored within the database is compared with the current time
  • If the database was last updated in the previous 10 minutes, then the display is changed
• format_images.py script allows one to drop JPEG images into the /pic library, and then transforms them to the dimensions required by the display (800x480)
  • These images are also saved to the /public directory for the react app to be displayed on the website
• message.py and message_repository.py are the same as found in the API
• /lib
  • All waveshare libraries - These are taken right from the waveshare/e-paper repo - Contains a c shared library and python example for writing to the 7.5" display
• /pic
  • Where pictures are stored and read from
• /font
  • Stores font for display

Crontab Entries

• */10 * * * * /home/pi/projects/love-box/RpiUpdateService/ShellScripts/update_display.sh >> /home/pi/logs/update_display_log.txt 2>&1
  • Ran every 10 minutes
• 0 0 * * * /home/pi/projects/love-box/RpiUpdateService/ShellScripts/auto_update.sh >> /home/pi/logs/git_log.txt 2>&1
  • Ran once a day
• Keep in mind that these paths are relative and will have to be adjusted based on where the repository files are stored on the raspberry pi

Part List

• Waveshare E-Paper 7.5" Display
• Simple 7"x5.5" picture frame
• Raspberry Pi Zero W
• 3D printed case to hold raspberry pi and waveshare pi hat
• USB power supply for the pi

Final Results

Displaying a Picture

Displaying Text

The Wiring

The Case Designed for the Pi + Waveshare Pi-HAT