This page introduces how to use OLED display with ODROID-HC4(-P) and the commands and packages in this page are based on Ubuntu 20.04.

RTC Module for HC4

If you have done the wiring well, you can see the device as the following commands.

sudo apt install i2c-tools

sudo i2cdetect -y -r 0

The simplest way to install the default packages to display date and time on OLED is to install the package prebuilt.

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$ sudo apt update
$ sudo apt install odroid-homecloud-display

Source code of this package : https://github.com/tobetter/odroid-homecloud

If you are willing to use the OLED for a development, you will need to install more packages after 'odroid-homecloud-display'. So please follow the instructions.

Firstly, install the dependency packages.

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$ sudo apt install git python-dev python3-pip libfreetype6-dev libjpeg-dev build-essential
$ sudo apt install libsdl-dev libportmidi-dev libsdl-ttf2.0-dev libsdl-mixer1.2-dev libsdl-mixer1.2 libfluidsynth2 libsdl2-2.0-0 libsdl-image1.2-dev

Secondly, download the example codes from Github.

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$ git clone https://github.com/rm-hull/luma.examples.git
$ cd luma.examples

Finally, install the python packages to run the examples.

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$ sudo -H pip3 install -e .

Please refer to the link for more detail about the examples. https://github.com/rm-hull/luma.examples#running-the-examples

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$ cd examples
$ sudo python3 3d_box.py --i2c-port 0 --rotate 2
Version: luma.oled 3.6.0 (luma.core 1.17.2)
Display: ssd1306
Interface: i2c
Dimensions: 128 x 64
------------------------------------------------------------

This example is to show the current date and time to the display, download the below code as clock.py.

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright (c) 2014-18 Richard Hull and contributors
# See LICENSE.rst for details.
# PYTHON_ARGCOMPLETE_OK
 
"""
An analog clockface with date & time.
"""
 
from luma.core.interface.serial import i2c
from luma.core.render import canvas
from luma.oled.device import ssd1306, ssd1325, ssd1331, sh1106
from time import sleep
from PIL import ImageFont, ImageDraw, Image
import time
import datetime
 
serial = i2c(port=0, address=0x3C)
# device = sh1106(serial, rotate=0)
device = ssd1306(serial, rotate=2)
 
def main():
    today_last_time = "Unknown"
    while True:
        now = datetime.datetime.now()
        today_date = now.strftime("%d %b %y")
        today_time = now.strftime("%H:%M")
        if today_time != today_last_time:
            today_last_time = today_time
            with canvas(device) as draw:
                  font = ImageFont.truetype('/root/fonts-DSEG_v046/DSEG7-Modern/DSEG7Modern-Bold.ttf',36)
                  # font = ImageFont.truetype('/root/luma.examples/examples/fonts/FreePixel.ttf',36)
                  draw.text((0, 27), today_time, font=font, fill=1)
                  font = ImageFont.truetype('/root/fonts-DSEG_v046/DSEG7-Modern/DSEG7Modern-Bold.ttf',20)
                  # font = ImageFont.truetype('/root/luma.examples/examples/fonts/FreePixel.ttf',20)
                  draw.text((0, 0), today_date, font=font, fill=1)
        time.sleep(0.1)
 
if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass

This script uses the true type font that is not included in the library, therefore additional fonts must be downloaded and installed to a directory. We will assume that the font file and python script is copied to /root directory in this example.

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root@odroid ~# wget https://github.com/keshikan/DSEG/releases/download/v0.46/fonts-DSEG_v046.zip
root@odroid ~# unzip fonts-DSEG_v046.zip
root@odroid ~# ls -l
drwxr-xr-x 12 root root    4096 Mar 15  2020 fonts-DSEG_v046

After copying the font files, run the python script clock.py.

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root@odroid ~# ./clock.py

If you want to change the font or its size, change the font name and its size in the script.

font = ImageFont.truetype('/root/fonts-DSEG_v046/DSEG7-Modern/DSEG7Modern-Bold.ttf',36)