Mini Ticker

This project is a purpose-built solution for retrieving and displaying various information that is important to the author.

Additionally, it has configured interfaces (button presses, NFC/RFID card/tag scan) which can trigger arbitrary actions (e.g. send magic packet). It aims to have a small footprint, with minimal maintenance.

The code provided here is based on examples (1, 2) from the pi-rc522 and adafruit-circuitpython-ssd1306 projects.

Requirements

• Raspberry Pi computer with installed header pins and power source
• compatible microSD/SD card
• SSD1306-based 128x64 or 128x32 pixel OLED display (I2C)
• (Optional) RC522 module (for RFID/NFC communication)

Setup

• Install Raspbian (Lite) on a microSD/SD card

• Set up the Raspberry Pi to run headless and connect it to your network (guide)

• ssh into the Raspberry Pi:

• Do sudo raspi-config and set up:

  • "Interfacing Options" > "Interfacing Options" > "I2C" > select "Yes"
  • (Optional) "Localisation Options"
  • (Optional) "Change User Password" Important! Because we're using a Raspberry Pi, the default user is pi with a password of raspberry - it is strongly advised to change the password, at minimum.

• Install dependencies:

  sudo apt update && sudo apt-get install git python3-pip python3-dev libtiff5-dev libopenjp2-7-dev

• (Optional) Enable Wake-on-LAN packet sending sudo apt-get install etherwake

• (Optional) If using a Temperature / Humidity sensor, do sudo apt-get install libgpiod2

• Clone this repo and cd mini-ticker

• Install required packages with pip3 install -r requirements.txt

• (Optional) Edit /boot/config.txt at the line dtparam=i2c_arm=on and replace it with:

  dtparam=i2c_arm=on,i2c_arm_baudrate=400000

• (Optional) If using an RC522 module for RFID/NFC communication, edit /boot/config.txt to include the following settings:

  device_tree_param=spi=on
  dtoverlay=spi-bcm2708
  dtparam=spi=on
  

• Edit or create .env in the same directory as status_display.py with the following contents:

  DHT11_PIN=4

Running the code

Once the ticker.py script is executed, it will continue to run until the process is terminated. You can manually execute the script on demand, or automatically execute on shell start by editing /etc/profile and appending the following to the end of the file (update the file path as needed):

python3 /home/pi/mini-ticker

Alternatively, run any given script as a service:

• Run sudo systemctl --force --full edit mini-ticker.service and enter the config:

  [Unit]
  Description=Mini Ticker
  Requires=network.target
  After=multi-user.target
  
  [Service]
  WorkingDirectory=/home/pi/mini-ticker
  User=pi
  ExecStart=python3 .
  ExecStopPost=python3 -c 'import ticker; ticker.shutdown()'
  
  [Install]
  WantedBy=multi-user.target
  

• Enable the service with sudo systemctl enable --now mini-ticker.service, and start it with sudo systemctl start mini-ticker.service

Other scripts that listen for triggers (e.g. card scan, button press) can be executed in the same way.

Notes

• This build assumes Raspberry Pi Zero hardware - no other Raspberry Pi hardware has been tested with this code.
• Ubuntu Font Family is included in /fonts by default. If you wish to use a different font, add them to the /fonts directory and update the import references in ticker.py (note, line spacing currently presumes Ubuntu fonts and may require adjustments when using other fonts).
• Tip: You can access the the target pi on your network using the pi's network DNS reference (raspberrypi by default). This is particularly useful if your network has dynamic IP address assignment; you can simply ssh pi@raspberrypi.local)

Supported Hardware

name	description
bme280	measures temperature, pressure, altitude, and relative humidity
bmp280	measures temperature, pressure, and altitude
dht11	measures temperature and relative humidity
dht22	measures temperature and relative humidity
RC522	Near-Field Communication (NFC) module
SSD1306	128 x 64 dot matrix OLED