LCD

This repository contains all the code for interfacing with a 16x2 character I2C liquid-crystal display (LCD). This accompanies my Youtube tutorial: Raspberry Pi - Mini LCD Display Tutorial.

You can buy one of these great little I2C LCD on eBay or somewhere like the Pi Hut.

Installation

• Install git

  sudo apt install git
  

• Clone the repo in your pi home directory

  cd /home/pi/
  git clone https://github.com/the-raspberry-pi-guy/lcd.git
  cd lcd/
  

• Run the automatic installation script with sudo permission

  sudo ./install.sh
  

• After rebooting, try one of the demos

  cd /home/pi/lcd/
  ./demo_clock.py
  

Demos

Simple strings

This is a demo developed by user @Tomtom0201, showing how simple text stings could be displayed on LCD:

Extended strings

This is a demo debeloped by @juvus, showing how extended strings could be used. Extended strings can contain special placeholders {0xFF} - hex code of the symbol wrapped with curly bracers. Hex code of the symbol can be found in characters table. For example code of the symbol ö is 0xEF, and so this symbol could be printed by using {0xEF} placeholder in string. Table can be found in /imgs/characters_table.png. If you want to combine placeholder to write a symbol {0xFF} with native python placeholder {0} for inserting dome data into text, escape those placeholders that is using to write a symbol. This is an example: display.lcd_display_extended_string("Symbol:{{0xEF}} data:{0}".format(5), 2)

Custom characters

It is possible to define in CG RAM memory 8 absolutelly custom characters. This characters can be pronted on LCD the same way as any characters from the character table. Codes of the custom characters are unique and the following: 1st - {0x00}, 2nd - {0x01}, 3rd - {0x02}, 4th - {0x03}, 5th - {0x04}, 6th - {0x05}, 7th - {0x06} and 8th - {0x07}. Please, see the demo_lcd_custom_characters.py file for more details, how it is possible to define you own characters. This demo was debeloped by @juvus.

Progress bar

This is a demo of graphical progress bar created with custom characters. This bar could be used, for example, for showing the current level of battery charge. This demo was debeloped by @juvus.

Backlight Control

This is a demo developed by user and watcher @Tomtom0201, showcasing backlight control of the LCD (available on some hardware):

Forex

This is a demo developed by user and watcher @bariskisir. It requires python-pip and the packages requests and bs4 (BeautifulSoup) because it parses web content.

• Install pip

  sudo apt install python-pip
  

• Then install requests and bs4

  pip install requests bs4
  

• Now you should be able to run demo_forex.py:

I haven't been able to test it myself personally, but it looks like a cool Forex stream. If you run into any bugs with it, please feel free to reach out to bariskisir and submit a PR.

IP Address

Another demo developed by @Sierra007117:

Display your Pi's IP address - useful for SSH'ing and more!

NetMonitor

A demo created by @cgomesu that uses ping and nc (netcat) to monitor the network status of hosts and services, respectively. This demo uses built-in tools, so nothing new needs to be installed.

Hosts and services can be modified by editing their respective dictionaries:

hosts = {
    'Internet': '8.8.8.8',
    'Firewall': '192.168.1.1',
    'NAS': '192.168.1.2'
}
services = {
    'Cameras': {'ip': '192.168.1.2', 'port': '8000'},
    'Plex': {'ip': '192.168.1.2', 'port': '32400'}
}

After editing the hosts and services dictionaries, you can run this demo in the background (as a service) as follows:

1. Create a new service file in /lib/systemd/system/ called rpi-netmonitor.service:

nano /lib/systemd/system/rpi-netmonitor.service

2. Copy and paste the following in the new service file:

[Unit]
Description=A RPi network monitor for a 16x2 LCD

[Service]
Type=simple
User=pi

ExecStart=/usr/bin/python /home/pi/rpi-lcd/demo_netmonit.py

Restart=always
RestartSec=5

KillMode=process
KillSignal=SIGINT

[Install]
WantedBy=multi-user.target

3. Enable the service and start it:

sudo systemctl enable rpi-netmonitor.service
sudo systemctl start rpi-netmonitor.service

4. Check that the LCD is displaying the correct information; otherwise, check the service status

sudo systemctl status rpi-netmonitor.service