Story
After last week’s Pi Zero mod, I thought I’d try a slightly more useful project. Using an Adafruit OLED display, two push buttons, a wifi dongle and a Pi Zero, I made an internet connected information display. The information could be anything: time and date, weather, social media status, etc … The two push buttons are used to cycle through the data and trigger certain actions.
Hardware
The hardware consists of the following components:
- Raspberry Pi Zero
- Adafruit 128×64 SSD1306 OLED
- Edimax wifi dongle
- 2 large push buttons
The wifi dongle is connected the same way as I did previously with the USB hub:
- Pi Zero PP1 to dongle 5V
- Pi Zero PP6 to dongle GND
- Pi Zero PP22 to dongle D+
- Pi Zero PP23 to dongle D-
Finally, to keep everything in place, I designed a simple enclosure just large enough to fit everything in. A back panel is screwed in place to keep all components inside, exposing the power input microUSB port on the side.
A bit of kapton tape prevents exposed contacts to touch each other and keeps the wiring in place. The wifi dongle is positioned at the top for better connectivity. Its bright blue LED shines through the enclosure, giving a clear indication on its status and activity.
The files for the 3D printable enclosure can be found on thingiverse: http://www.thingiverse.com/thing:1193350
Software
For the software side of the project, I started off by creating the microSD card using the latest Raspbian Jessie image available. I booted it from the Pi Zero/USB hub combo with keyboard and wifi dongle connected. I’m using this approach because this project’s Pi Zero’s USB port has been hardwired to a wifi dongle and a keyboard can no longer be connected.
I configured the wifi by adding the correct SSID and passphrase in the /etc/network/interfaces file. After testing the wifi connectivity, I put the microSD card back in the correct Pi. With network connectivity, it is possible to log in using SSH and work on the script to display the desired information.
Using the Adafruit OLED SSD1306 Python Library and some custom Python code, I programmed three different displays:
- Time & date
- Network settings
- Social media subscribers/followers
The left button cycles through the different screens, while the right button triggers a custom action per screen.
In the case of the time and date display, the button simply toggles between 12h and 24h representation. For the network settings, it forces the wifi to reconnect by bringing down the interface and forcing it up again. Finally, to avoid excessive traffic, social media information is only retrieved every five minutes, pressing the button forces the retrieval of information.
For more detail: Raspberry Pi Zero Internet Connected Information Display