Python script to display Raspberry Pi status on SSD1306-based 128x64px OLED connected via I2C

install.sh

#!/bin/bash

# Prerequisite:
# Enable I2C using raspi-config if necessary

# Install I2C support, Python image library, and other support libraries.
sudo apt install -y python3-smbus i2c-tools
sudo apt install -y python3-pil
sudo apt install -y python3-pip
sudo apt install -y python3-setuptools
sudo apt install -y python3-rpi.gpio

# Install Adafruit SSD1306 driver. This is the older version that
# does not depend on the CircuitPython abstraction layer.
git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
cd Adafruit_Python_SSD1306
sudo python setup.py install
cd ..

# Install the process utilities library that is used by the script.
sudo apt install python3-psutil

# Install the font used by the script
wget https://github.com/google/fonts/raw/376ff5c1ab3952ec7d324a2222f1018a09b2a437/apache/roboto/static/Roboto-Regular.ttf -P Roboto
sudo cp -r Roboto /usr/share/fonts/truetype

# Install the script
sudo cp oled_status.py /usr/local/bin/oled_status
sudo chmod +x /usr/local/bin/oled_status

# Create a user to run the script
sudo useradd -r oled
sudo usermod -a -G i2c oled

# Install the service
sudo cp oled.service /lib/systemd/system
sudo systemctl start oled
sudo systemctl enable oled

oled.service

[Unit]
Description=OLED Status Display

[Service]
User=oled
ExecStart=/usr/local/bin/oled_status
SyslogIdentifier=oled
Type=simple
Restart=on-failure
RestartSec=30
Nice=10

[Install]
WantedBy=default.target

oled_status.py

#! /usr/bin/python3

# Loosely based on Adafruit_Python_SSD1306/examples/stats.py
#
# Modified to use psutil instead of spawning shells to run commands to get stats.
# This, plus sleeping to yield after getting stats and updating image, plus
# reducing the update rate to only every 3s, dramatically lowers the CPU usage.
# To further reduce impact on other real-time programs, run with 'nice'.

import time
import psutil
import Adafruit_SSD1306
from PIL import Image, ImageDraw, ImageFont

# 128x64 display with hardware I2C:
disp = Adafruit_SSD1306.SSD1306_128_64(rst=None)

# Initialize and clear the display.
disp.begin()
disp.clear()
disp.display()

# Create a blank 1-bit image and get an associated drawing object.
image = Image.new('1', (disp.width, disp.height))
draw = ImageDraw.Draw(image)

# Load a TTF font from a .ttf file and set the height in pixels.
font = ImageFont.truetype('/usr/share/fonts/truetype/Roboto/Roboto-Regular.ttf', 12)

while True:

    # Draw a black filled box to clear the image.
    draw.rectangle((0, 0, disp.width, disp.height), outline=0, fill=0)

    # Get stats to display.
    ip_addr = psutil.net_if_addrs()['wlan0'][0].address
    cpu_percent = psutil.cpu_percent()
    cpu_load = psutil.getloadavg()
    mem_usage = psutil.virtual_memory()
    disk_usage = psutil.disk_usage('/')
    temperature = psutil.sensors_temperatures()['cpu_thermal'][0].current
    time.sleep(0.1)

    # Write text to the image.
    draw.text((0, 0),   "IP %s" % (ip_addr),  font=font, fill=255)
    draw.text((0, 12),  "CPU %d%% Load %.2f" % (cpu_percent, cpu_load[0]), font=font, fill=255)
    draw.text((0, 24),  "Mem %d/%dM %d%%" % (mem_usage.used/(1<<20), mem_usage.total/(1<<20), mem_usage.percent), font=font, fill=255)
    draw.text((0, 36),  "Disk %d/%dG %d%%" % (disk_usage.used/(1<<30), disk_usage.total/(1<<30), disk_usage.percent), font=font, fill=255)
    draw.text((0, 48),  "Temp %dC" % (temperature), font=font, fill=255)
    time.sleep(0.1)

    # Display image.
    disp.image(image)
    disp.display()
    time.sleep(3)