Display Pi Hostname, IP address, and wlan0 MAC address on an hot swappable I2C SSD1306 OLED

display_pi_info.py

# Modified by: Nik Martelaro 2019
# Changes: Get hostname and MAC address and display on OLED

# THANK YOU ADAFRUIT FOR MAKING SUCH GREAT HARDWARE AND SOFTWARE <3

# Copyright (c) 2017 Adafruit Industries
# Author: Tony DiCola & James DeVito
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
import time

import RPi.GPIO as GPIO

import Adafruit_GPIO.SPI as SPI
import Adafruit_SSD1306

from PIL import Image
from PIL import ImageDraw
from PIL import ImageFont

import subprocess


# Raspberry Pi pin configuration:
RST = None     # on the PiOLED this pin isnt used
# Note the following are only used with SPI:
#DC = 23
#SPI_PORT = 0
#SPI_DEVICE = 0

# Turn Pin 4 high to use as power
GPIO.setmode(GPIO.BCM)
GPIO.setup(4, GPIO.OUT, initial=1)

# Beaglebone Black pin configuration:
# RST = 'P9_12'
# Note the following are only used with SPI:
# DC = 'P9_15'
# SPI_PORT = 1
# SPI_DEVICE = 0

# 128x32 display with hardware I2C:
disp = Adafruit_SSD1306.SSD1306_128_32(rst=RST)

# 128x64 display with hardware I2C:
# disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST)

# Note you can change the I2C address by passing an i2c_address parameter like:
# disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST, i2c_address=0x3C)

# Alternatively you can specify an explicit I2C bus number, for example
# with the 128x32 display you would use:
# disp = Adafruit_SSD1306.SSD1306_128_32(rst=RST, i2c_bus=2)

# 128x32 display with hardware SPI:
# disp = Adafruit_SSD1306.SSD1306_128_32(rst=RST, dc=DC, spi=SPI.SpiDev(SPI_PORT, SPI_DEVICE, max_speed_hz=8000000))

# 128x64 display with hardware SPI:
# disp = Adafruit_SSD1306.SSD1306_128_64(rst=RST, dc=DC, spi=SPI.SpiDev(SPI_PORT, SPI_DEVICE, max_speed_hz=8000000))

# Alternatively you can specify a software SPI implementation by providing
# digital GPIO pin numbers for all the required display pins.  For example
# on a Raspberry Pi with the 128x32 display you might use:
# disp = Adafruit_SSD1306.SSD1306_128_32(rst=RST, dc=DC, sclk=18, din=25, cs=22)

def setup():
    try:
        # Initialize library.
        disp.begin()
        return disp
    except OSError:
        time.sleep(10)
        # try to setup again
        setup()

def draw_info(disp):
    # Create blank image for drawing.
    # Make sure to create image with mode '1' for 1-bit color.
    width = disp.width
    height = disp.height
    image = Image.new('1', (width, height))

    # Get drawing object to draw on image.
    draw = ImageDraw.Draw(image)

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

    # Draw some shapes.
    # First define some constants to allow easy resizing of shapes.
    padding = -2
    top = padding
    bottom = height-padding
    # Move left to right keeping track of the current x position for drawing shapes.
    x = 0


    # Load default font.
    font = ImageFont.load_default()

    # Alternatively load a TTF font.  Make sure the .ttf font file is in the same directory as the python script!
    # Some other nice fonts to try: http://www.dafont.com/bitmap.php
    # font = ImageFont.truetype('Minecraftia.ttf', 8)

    while True:

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

        # Shell scripts for system monitoring from here : https://unix.stackexchange.com/questions/119126/command-to-display-memory-usage-disk-usage-and-cpu-load
        cmd = "hostname"
        HOST = subprocess.check_output(cmd, shell = True ).decode('utf-8')
        cmd = "hostname -I | cut -d\' \' -f1"
        IP = subprocess.check_output(cmd, shell = True ).decode('utf-8')
        # Get MAC address from the Shell: https://askubuntu.com/questions/628383/output-only-mac-address-on-ubuntu
        cmd = "cat /sys/class/net/wlan0/address"
        MAC = subprocess.check_output(cmd, shell = True ).decode('utf-8')

        # Write lines of text.
        draw.text((x, top),      "HOST:{}".format(HOST),  font=font, fill=255)
        draw.text((x, top + 8),  "IP:{}".format(IP),      font=font, fill=255)
        draw.text((x, top+16),   "MAC:{}".format(MAC),    font=font, fill=255)

        # Clear display.
        disp.clear()

        # Display image.
        disp.image(image)
        disp.display()
        time.sleep(10) # only update every so often so we don't use as much CPU

setup()
while True:
    try:
        draw_info(disp)
    except OSError:
        setup()