Category: Technotes

OK, this one is the simps. I have a Raspberry Pi connected to a monitor. Whenever the Pi starts up, I want it to automatically load my air quality dashboard in full-screen (kiosk) mode. I don’t want to use a keyboard, mouse or other user action, I just want it to start up and show a webpage, using the full-screen kiosk mode.

Here’s how to do it:

Edit the lxsession autostart file with the following:

sudo nano /etc/xdg/lxsession/LXDE-pi/autostart

At the bottom of the file, add:

@/usr/bin/chromium-browser --kiosk https://kis.support/h200

That’s it. Whenever your Pi reboots, it’ll load up the webpage (in this case https://kis.support/h200).

Pro Tip: The Rapsberry Pi’s default screensaver can be a pain in the neck. I disabled it by installing xscreensaver with:

sudo apt install xscreensaver

Then, click the Raspberry “Home” button > Preferences > Screensaver. In the top dropdown “Mode” menu, select “Disable Screen Saver”. Then sit back and get ready for some serious burn-in.

Note: This is a draft post - published for Paul to find more easily. It's not complete as long as this paragraph is here, but the initial steps will be needed before progressing further.

Install Linux Mint

Setup VNC Access (per LinuxMint tutorial)

1. Remove the default Vino server:

sudo apt-get -y remove vino

2. Install x11vnc:

sudo apt-get -y install x11vnc

3. Create the directory for the password file:

sudo mkdir /etc/x11vnc

4. Create the encrypted password file:

sudo x11vnc –storepasswd /etc/x11vnc/vncpwd

You will be asked to enter and verify the password.  Then press Y to save the password file.

5. Create the systemd service file for the x11vnc service:

sudo nano /lib/systemd/system/x11vnc.service

Copy/Paste this code into the empty file:

[Unit]
Description=Start x11vnc at startup.
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/x11vnc -auth guess -forever -noxdamage -repeat -rfbauth /etc/x11vnc/vncpwd -rfbport 5900 -shared

[Install]
WantedBy=multi-user.target

6. Reload Daemon

sudo systemctl daemon-reload

7. Enable the x11vnc service at boot time:

sudo systemctl enable x11vnc.service

8. Start the service:

Either reboot or

sudo systemctl start x11vnc.service

Enable ssh access

sudo apt install openssh-server

Nebula VPN Setup

For external VPN access, use node16 (Paul knows)

Static ip Address Setup

Info for setting static ip address and access from off campus

Samba Server Setup

Install Samba

sudo apt update
sudo apt install samba

Samba setup

mkdir /home/<user>/sambashare/
sudo nano /etc/samba/smb.conf

Add the following to smb.conf:

[sambashare]
    comment = Samba on Ubuntu
    path = /home/username/sambashare
    read only = no
    browsable = yes

Restart service and allow firewall traffic:

sudo service smb restart
sudo ufw allow samba

Set up User Accounts

sudo smbpasswd -a username

Hello and welcome to Mr Ericksen’s home on the web. This isn’t so much a portfolio of my work as it is a place for me to archive my projects and processes while providing a convenient way for me to share them with others who may be interested in using them.

If you’re just browsing around, Technotes are tech-related projects I’ve worked on as an IT Director and EdSys Admin, Travel Hacks is a collection of things I’ve found helpful during since moving abroad in 2006, and Pro Tips are some short tips for making daily life a little less stressful.

Edward, one of our 11th grade students on the school’s yearbook team wanted to build an index of page numbers where each student appeared. Traditionally, this would entail multiple students going through every page and recording the page number for each student appearing on that page. Inevitably, some students get missed, errors are made, and some pages get skipped.

Edward, recognizing an opportunity to leverage his programming skills, wrote a Python script to collect the information in a much more efficient manner. His script reads two columns from a Google Spreadsheet into lists named name and nameraw. Then, for each name in the lists, the script searches each page of the yearbook pdf and logs each page number where the name is located. Finally, this data is written back to the Google sheet.

This script leverages Google sheets, but with minor alteration, it could easily use locally stored files instead. Note that this script depends on a number of dependencies, so don’t forget to add those that you may not yet have installed (PyPDF2, re, pathlib, and the relevant Google auth and client libraries). If you’re unfamiliar with the Google python libraries, well, that will need to be another Google search. However, if you use local files rather than reading from a Google sheet, those libraries (and the code between the dashed lines) could be excluded. You would just need to replace those lines with a couple others that would open your csv file with the list(s) of names.

This is Edward’s script and I had no hand in creating or using it. If you want to use it yourself, you’re welcome to do so. If you get stuck, check with one of your programming students or teachers first. If you’re still stuck, comment below and I’ll help out if I can.

from __future__ import print_function
import os.path      
from PyPDF2 import PdfFileReader, PdfFileWriter
from pathlib import Path
import re
import PyPDF2

#-----------------------------------------------------
from google.auth.transport.requests import Request
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from google.oauth2 import service_account

# Note that you will need to set up your own Google API credentials if
# you're using Google Sheets. This part is beyond the scope of this post.
# But you can find how to do this with a quick google search. 
SERVICE_ACCOUNT_FILE = 'keys.json'
SCOPES = ['https://www.googleapis.com/auth/spreadsheets']
creds = None
creds = service_account.Credentials.from_service_account_file(
        SERVICE_ACCOUNT_FILE, scopes=SCOPES)

# The ID and range of the spreadsheet. Note that the ID below is fake
# (we're not going to post the real one on the interwebs)
# Make sure you update the ID to refer to your spreadsheet
SPREADSHEET_ID = '1DQyjh1-7T9jjU7kmg6-TNcjsCtnCspWiMbv3t2mJeM'

service = build('sheets', 'v4', credentials=creds)

# Call the Sheets API
sheet = service.spreadsheets()
result = sheet.values().get(spreadsheetId=SPREADSHEET_ID,
                            range="Sheet1!B1:B508").execute()
result2 = sheet.values().get(spreadsheetId=SPREADSHEET_ID,
                            range="Sheet1!A1:A508").execute()
#------------------------------------------------------------
values = result.get('values')
values2 = result2.get('values')

name = []
nameraw = []
#put names from values and values2 into lists
for x in values:
        for i in x:
                name.append(i)

for x in values2:
        for i in x:
                nameraw.append(i)

#Open the Yearbook pdf file
pdf = PdfFileReader('yearbook1.pdf')

#create a 2-D array for names & associated page numbers
pagesfinal = [[]]

#This is where everything happens. For each name, add it to pagesfinal.
#Then open each page in the pdf file and search it for the current name.
#If a version of the name is found, append the page number to the student's page list.

for i in range(len(name)):
        print(nameraw[i])
        pagesfinal.append([])
        for page_num in range (pdf.numPages):    
                pageobj = pdf.getPage(page_num)
                pageinfo = pageobj.extractText()
                pageinfo = ''.join(pageinfo.split())
                name[i]= ''.join(str(name[i]).split())
                nameraw[i] = ''.join(str(nameraw[i]).split())
                if (re.search(name[i], pageinfo)) or (re.search(nameraw[i], pageinfo)) or (re.search(name[i].upper(), pageinfo)):
                        pagesfinal[i].append(page_num +1)
                        print(pagesfinal[i])

#When the above loop completes, the following line writes the data back to the Google sheet
        request = sheet.values().update(spreadsheetId=SPREADSHEET_ID, range="Sheet1!C1", valueInputOption = "USER_ENTERED", body={"values":pagesfinal}).execute()

Long story short? I made an RPi sound clip player using a tft touchscreen, pygame, and movie quotes found on YouTube. It starts with a small, 3.5″ touchscreen whose drivers are installed using the instructions here. For your convenience, they are replicated below.

Just enter these lines into Terminal to get the screen set up.

sudo rm -rf LCD-show
git clone https://github.com/goodtft/LCD-show.git
chmod -R 755 LCD-show
cd LCD-show/
sudo ./LCD35-show

This should get the screen running properly. If you have issues with axes being reversed on the screen (like you touch the right side and the cursor shows up on the left) the page linked above has some suggestions. If those don’t help, check out Teng Fone’s post on Medium.

OK, now (hopefully) the screen is working and we can work on the code. I used code from Garth Vander Houwen’s Pi tft menu project as a starting point, added some audio files, and came up with a project that presently shows this screen on my Raspberry Pi:

You might guess some (or all) of the audio files I used. If not, you can download them from here.

The Python script to get it all running is below (or access it here). Connect the audio output to your speakers or headphones and click away. Examining the code should make it relatively easy to modify it to change the sounds, number of options, etc.

import sys, pygame, time, subprocess, os
from pygame.locals import *
from pygame import mixer
from subprocess import *

os.environ["SDL_FBDEV"] = "/dev/fb1"
os.environ["SDL_MOUSEDEV"] = "/dev/input/touchscreen"
os.environ["SDL_MOUSEDRV"] = "TSLIB"

# Initialize pygame modules individually (to avoid ALSA errors) and hide mouse
pygame.font.init()
pygame.display.init()
pygame.mouse.set_visible(0)
pygame.display.toggle_fullscreen

# define function for printing text in a specific place with a specific width and height with a specific colour and border
def make_button(text, xpo, ypo, height, width, colour):
    font=pygame.font.Font(None,42)
    label=font.render(str(text), 1, (colour))
    screen.blit(label,(xpo,ypo))
    pygame.draw.rect(screen, blue, (xpo-10,ypo-10,width,height),3)

# define function for printing text in a specific place with a specific colour
def make_label(text, xpo, ypo, fontsize, colour):
    font=pygame.font.Font(None,fontsize)
    label=font.render(str(text), 1, (colour))
    screen.blit(label,(xpo,ypo))

# define function that checks for touch location
def on_touch():
    # get the position that was touched
    touch_pos = (pygame.mouse.get_pos() [0], pygame.mouse.get_pos() [1])
    #  x_min                 x_max   y_min                y_max
    # button 1 event
    if 30 <= touch_pos[0] <= 240 and 30 <= touch_pos[1] <=85:
            button(1)
    # button 2 event
    if 260 <= touch_pos[0] <= 470 and 30 <= touch_pos[1] <=85:
            button(2)
    # button 3 event
    if 30 <= touch_pos[0] <= 240 and 105 <= touch_pos[1] <=160:
            button(3)
    # button 4 event
    if 260 <= touch_pos[0] <= 470 and 105 <= touch_pos[1] <=160:
            button(4)
    # button 5 event
    if 30 <= touch_pos[0] <= 240 and 180 <= touch_pos[1] <=235:
            button(5)
    # button 6 event
    if 260 <= touch_pos[0] <= 470 and 180 <= touch_pos[1] <=235:
            button(6)
    # button 7 event
    if 30 <= touch_pos[0] <= 240 and 255 <= touch_pos[1] <=310:
            button(7)
    # button 8 event
    if 260 <= touch_pos[0] <= 470 and 255 <= touch_pos[1] <=310:
            button(8)

# Define each button press action
def button(number):
    print("You pressed button", number)

    if number == 1:
        #time.sleep(0.2) #do something interesting here
	mixer.init()
	mixer.music.load('Illbeback.mp3')
	mixer.music.set_volume(1)
	mixer.music.play()
	time.sleep(5)
        #sys.exit()

    if number == 2:
        #time.sleep(5) #do something interesting here
        #sys.exit()
	mixer.init()
        mixer.music.load('wickedsmart.mp3')
        mixer.music.set_volume(1)
        mixer.music.play()
        time.sleep(5)

    if number == 3:
        #time.sleep(5) #do something interesting here
        #sys.exit()
	mixer.init()
        mixer.music.load('thatlldopig.mp3')
        mixer.music.set_volume(1)
        mixer.music.play()
        time.sleep(5)

    if number == 4:
        #time.sleep(5) #do something interesting here
        #sys.exit()
	mixer.init()
        mixer.music.load('killingmesmalls.mp3')
        mixer.music.set_volume(1)
        mixer.music.play()
        time.sleep(5)

    if number == 5:
        #time.sleep(5) #do something interesting here
        #sys.exit()
	mixer.init()
        mixer.music.load('failuretocommunicate.mp3')
        mixer.music.set_volume(1)
        mixer.music.play()
        time.sleep(5)

    if number == 6:
        #time.sleep(5) #do something interesting here
        #sys.exit()
	mixer.init()
        mixer.music.load('goodafternoon.mp3')
        mixer.music.set_volume(1)
        mixer.music.play()
        time.sleep(5)

    if number == 7:
        time.sleep(2) #do something interesting here
        #sys.exit()

    if number == 8:
        time.sleep(5) #do something interesting here
        sys.exit()

#colors     R    G    B
white   = (255, 255, 255)
red     = (255,   0,   0)
green   = (  0, 255,   0)
blue    = (  0,   0, 255)
black   = (  0,   0,   0)
cyan    = ( 50, 255, 255)
magenta = (255,   0, 255)
yellow  = (255, 255,   0)
orange  = (255, 127,   0)

# Set up the base menu you can customize your menu with the colors above

#set size of the screen
size = width, height = 480, 320
screen = pygame.display.set_mode(size)

# Background Color
screen.fill(black)

# Outer Border
pygame.draw.rect(screen, blue, (0,0,480,320),10)

# Buttons and labels
# First Row
make_button("I'll be back", 30, 30, 55, 210, blue)
make_button("Wicked Smart", 260, 30, 55, 210, blue)
# Second Row
make_button("That'll Do", 30, 105, 55, 210, blue)
make_button("Killing me", 260, 105, 55, 210, blue)
# Third Row
make_button("Failure", 30, 180, 55, 210, blue)
make_button("Good Night", 260, 180, 55, 210, blue)
# Fourth Row
make_button("Don't do nothin", 30, 255, 55, 210, blue)
make_button("Exit", 260, 255, 55, 210, blue)

#While loop to manage touch screen inputs
while 1:
    for event in pygame.event.get():
        if event.type == pygame.MOUSEBUTTONDOWN:
            pos = (pygame.mouse.get_pos() [0], pygame.mouse.get_pos() [1])
            on_touch()

        #ensure there is always a safe way to end the program if the touch screen fails
        if event.type == KEYDOWN:
            if event.key == K_ESCAPE:
                sys.exit()
    pygame.display.update()
    ## Reduce CPU utilisation
    time.sleep(0.1)

We had tried a few years ago to get some ancient MacBooks up and running with various Linux distros. But our particular model had challenging WiFi hardware which made it impractical.

I recently took another shot at reinvigorating our Early 2011 MacBook Pros with Ubuntu and found that a few terminal commands would get things working. I used Andy Bleaden’s steps from this AskUbuntu answer. I’ve pasted the steps below to ensure I always have ready access to it.

From Andy Bleaden:
I always recommend removing and reinstalling the broadcom drivers using your terminal

In a terminal type the following command

sudo apt-get purge bcmwl-kernel-source

then

sudo apt-get install bcmwl-kernel-source

This will then rebuild your driver.

You can either restart your pc or if this is a pain type the following commands in the terminal which will ‘switch on’ your wireless

sudo modprobe -r b43 ssb wl

then

sudo modprobe wl 

Suppose a student tests positive for COVID-19. Here’s how we quickly identify potentially exposed classmates. There’s a sample spreadsheet here that you can use. Just make a copy, follow the steps below and paste the export into cell A1 of the PS_DataDump tab. If that link breaks, you can download an Excel version here.

1. In DDE, select the CC Table
2. Search for current TermID and StudentID
3. Switch over to Sections Table
4. Search for Sections in current term
5. Match Selection on CC table
6. Switch to CC Table
7. Select all enrollments from current term
8. Match Selection with Sections Table
9. Export Records with the following records:

[1]Student_Number
[1]ID
SectionID
Course_Number
Expression
[2]Course_Name
[1]First_Name
[1]Last_Name
[1]Grade_Level
[1]Gender
[1]Home_Room
[183]Student_EMail
[5]First_Name
[5]Last_Name
[5]Email_Addr
[1]MotherDayPhone
[1]FatherDayPhone
[1]cnt1_email
[1]cnt2_email
[1]GuardianEmail

In our ever increasing efforts to protect student confidentiality and personal information, we password protect student report cards and test results when emailing them to parents. This helps protect the information in the unlikely event that an email gets sent to the incorrect address.

To do this, we generate the reports from PowerSchool or Google Docs, typically in a Firstname Lastname grade # Progress Report.pdf format. These are put into a folder (in this case, the folder is ES_T3_PDFs) there is also a filedata.csv file that has each file’s password in the first column, the original filename in column 8, and the new filename in column 9.

The python script below then runs, opens each report, creates a new file object, password protects it, and writes it to a new folder (Secure_ES_T3_PDFs).

import PyPDF2
import csv
import sys
#Open csv with password,filename,newfilename
c = open('filedata.csv', 'r')
# Create a reader object to store the data in filedata.csv
reader = csv.reader(c, delimiter=',')
# Process each row of data
count = 0
for row in reader:
    # The password located in the first column
    password = str(row[0])
    # The current (original) filename in "firstname lastname grade # Progress Report - Student_Number" format
    currFileName = row[7]
    # New filename is the same as original but without the Student_Number 
    newFileName = row[8]
    # Skip the header row
    if (password != "Password"): # Skip the first row with "Password" in first column
        # print row # every 10th row - just to monitor progress
        if (count % 10 == 0):
            print(count)
        # Open non-encrypted file
        pdfFile = open("PasswordProtect/ES_T3_PDFs/"+currFileName, 'rb')
        #coverLetter = open("PasswordProtect/coverLetter.pdf", 'rb')
        # Create reader and writer objects
        pdfReader = PyPDF2.PdfFileReader(pdfFile)
        #pdfReader02 = PyPDF2.PdfFileReader(coverLetter)
        pdfWriter = PyPDF2.PdfFileWriter()
        # The next 2 lines put the welcome letter at the beginning of the new file
        #print("Inserting Cover Letter")
        #for pageNum in range(pdfReader02.numPages):
        #    pdfWriter.addPage(pdfReader02.getPage(pageNum))
        # Add all pages to writer for each page in input file, add it to the output file
        for pageNum in range(pdfReader.numPages):
            pdfWriter.addPage(pdfReader.getPage(pageNum))
        # Encrypt with password
        pdfWriter.encrypt(password)
        # Write it to an output file
        resultPdf = open("PasswordProtect/Secure_ES_T3_PDFs/"+newFileName, 'wb')
        pdfWriter.write(resultPdf)
        resultPdf.close()
    count += 1

Peculiar enrollment situations can lead to issues when permanently storing grades at the end of a term. For instance, if a student changes from one section of a course to another during a term, one grade could get stored for each section if the “Exclude enrollments” dates are not selected wisely.

While we keep a file of “Special Cases” to review at the end of each term, but there are often such cases that sneak by us. To catch them, I track down all enrollment anomalies before storing grades.

To do this, I use DDE (…/admin/tech/dde/):

In DDE:

• Select the CC table
• TermID >= current year term (2900, 3000, 3001, etc.)
• SchoolID = 200 for MS or 300 for HS (in our case)
• DateEnrolled >= “A couple weeks after the start of the term”
• Export to a spreadsheet
• Sort by course name and delete non-courses: clubs, sports, A-Block, etc.
• Sort by DateEnrolled and look for any peculiar dates later in the term
• Decide appropriate cutoff date for “enrolled… after”
• Note any enrollments that may be improperly included or rejected for later followup
• Repeat above steps changing DateEnrolled to DateLeft and find an appropriate time for “dropped… before”

I typically check “Exclude … dropped before…” about a week before the end of the current term. Checking for outlier dates can help identify individual students and enrollments that may need attention.