This runs a Raspberry Pi as a controller for a school bell.
It makes the school bell ring at the right times taking the calendar into consideration.
Also there is an LCD screen to visualize time, database stats, upcoming rings etc.

Administration of the school bell is done via a web UI.

It is written entirely in python.

It makes use of the Adafruit_Python_CharLCD library. (https://github.com/adafruit/Adafruit_Python_CharLCD)

Also it installs gpio-watch to catch the buttons connected to the Pi's GPIO. (https://github.com/larsks/gpio-watch)

Changed all GPIO pins to make an easier PCB layout possible.
This makes all older electric installs incompatible.
Added KiCad files for new pin layout.

Corrected editing of ring times.

Bug discovered
There was a fault in the database setup.
Instead of updating, you can:
Log in to database

$ sudo mysql -u root -p piSchoolBell

Change column type

MariaDB [piSchoolBell]> ALTER TABLE ringTimes CHANGE weekDays weekDays VARCHAR(7);

• 1 x Raspberry Pi 3 B+, kjell.com Art#88100 (could be any of the later models)

• 1 x LCD display, kjell.com Art#90215 (16x2 characters, based on the HD44780 chip)

• 1 x USB micro power adapter, kjell.com Art#88525

• 1 x Micro SD card, kjell.com Art#97600

• 1 x 10k potentiometer, kjell.com Art#90633

• 1 x 5V relay module, kjell.com Art#87878

• 4 x Push button, kjell.com Art#36023

• 4 x 10k resistor

• 4 x 1k resistor

• 1 x Switch, kjell.com Art#36016

• 1 x Casing for rpi, kjell.com Art#89030

• 1 x Casing for relay, kjell.com Art#89014

• 1 x RTC-module, kjell.com Art#87984

• 1 x CR2032 battery, kjell.com ART#33715

• GPIO header connector, kjell.com Art#87915 (or breakout board)

• Wiring, cables

• PCB board, kjell.com Art#89416 or Art#89435 (or a breadboard, just to set it up)

• Soldering material

Assemble all the parts according to the files and images in the 'Documents' folder.

Download Raspbian Stretch Lite from 'https://www.raspberrypi.org/downloads/raspbian/'.
Choose the Light zip-file.

Cd to where your download is.

$ unzip 2017-11-29-raspbian-stretch-lite.zip

Insert SD-card and find out drive letter.

$ dmesg

For example '/dev/mmcblk0' or '/dev/sdb'.

Unmount if mounted.

$ umount /dev/mmcblk0p1

$ umount /dev/mmcblk0p2

Write image to SD-card.

$ sudo dd bs=4M if=2017-11-29-raspbian-stretch-lite.img of=/dev/mmcblk0 conv=fsync status=progress

Remove SD-card and insert it again to make new partitons visible.

Mount the first partition.

$ sudo mount /dev/mmcblk0p1 /mnt/tmp

Write empty file to boot partition to enable ssh at boot.

$ sudo touch /mnt/tmp/ssh

Unmount.

$ sudo umount /mnt/tmp

Remove SD-card and insert it a Rpi connected to your local network and boot it up.

Connect to Rpi via ssh.
Login with user: 'pi' and password: 'raspberry'.

$ sudo raspi-config

1 Change password
2 N1 Change hostname
2 N2 Set SSID and passphrase
4 I1 Set locales
4 I2 Set time zone
4 I3 Choose keyboard layout
4 I4 Set wifi country
7 A1 Expand file system to use whole SD-card
7 A3 Set memory split to 16

Reboot to set new options.

Connect again.

$ sudo apt-get update && sudo apt-get upgrade

$ sudo apt-get install git

$ cd /home/pi

$ git clone https://github.com/jonsag/piSchoolBell.git

$ cd /home/pi/piSchoolBell

$ sudo ./install.sh

$ sudo mysql_secure_installation

Set root password, and press 'enter' on all remaining questions

Use the same password as login for user pi.
Quit with 'exit;'.

$ sudo /home/pi/piSchoolBell/mysql-setup.sh

$ sudo /home/pi/piSchoolBell/www-secure-setup.sh

$ /home/pi/bin/piSchoolBell/getCalendar.py -v

See 'Issues' below if you get problem with this

$ sudo mysql -u root -p piSchoolBell < /home/pi/piSchoolBell/mysql-test-data.sql

Use the raspi-config you used earlier.

$ sudo raspi-config

5 P5 Enable I2C interface

$ ./install-rtc.sh

Check that time and date is correct

$ date

Set hardware clock

$ sudo hwclock -w

Comment out the following lines in /lib/udev/hwclock-set

if [ -e /run/systemd/system ] ; then  
	exit 0  
fi 

Reboot

Press button on unit to display its IP-address on the second line of the LCD.
Connect to the unit by pointing your browser to

http://\<IP-address\>:8080'.  

Edit or add breaks, ring times and ring patterns.

Remember, you can't really add rings on saturdays or sundays, as this is mainly intended for use on normal school schedules.

At the first of every month cron will download calendar from 'dryg.net', adding data to the database.
Every night cron will delete past breaks and days from the database.

Normally the LCD display shows:
Line 1: HH:MM YYYY-mm-dd, current time and date
Line 2: HH:MM YYYY-mm-dd, the time and date for the next bell ring

By pressing button 1, display will show:
    Line 1: days left in db, last date in db
    Line 2: IP-address
        If it shows 'Not connected' it has not been able to acquire an IP address.
        The first character on line 2 shows if the unit can access internet.
        If it is a '*' it is connected.
        If it is a '-' it is not connected.

Pressing button 2 will make the LCD go back to showing default info.

To dump database and logs to USB-stick:
Format a stick to fat32 and label it 'PISCHOOLBEL'.
Insert into Pi.
    Display will show:
        The USBs label and drive letter
        'USB mounted'
Press button 3.
    Display will confirm writing
    When finished display shows number of files written

Remove USB
    Display will show:
        drive letter
        'USB umounted'

Edit the database file with the highest date and time on the stick.

To read back edited file to database:
Insert the USB-stick.
    Display will show:
        The USBs label and drive letter
        'USB mounted'
Press button 4.
    Display will confirm reading
    ...
Not implemented yet.
For now it only shows how many lines to read back to the database.

If you get problems with Adafruit_Python_CharLCD failing to write to LCD.

$ cd /home/pi/piSchoolBell/Adafruit_Python_CharLCD

$ sudo python setup.py install

Check system time:

$ date

Check HW-time:

$ sudo hwclock -r

Set HW-clock to system time:

$ sudo hwclock -w

Set system clock from HW-clock:

$ sudo hwclock -s

Set system date manually:

$ date +%Y%m%d -s "20120418"

Set system time manually:

$ date +%T -s "11:14:00"

Set HW-clock manually:

$ sudo hwclock --set --date="2011-08-14 16:45:05"

$ rsync -raci ~/Documents/EclipseWorkspace/piSchoolBell/* [email protected]:/home/pi/bin/piSchoolBell/

$ rsync -raci ~/Documents/EclipseWorkspace/piSchoolBell/www/* [email protected]:/var/www/piSchoolBell/

$ ssh [email protected] 'sudo chmod 755 -R /var/www/piSchoolBell'

$ ssh [email protected] 'sudo chown -R pi:www-data /var/www/piSchoolBell'

$ rsync -raci ~/Documents/EclipseWorkspace/piSchoolBell/purgeDatabase.py [email protected]:/home/pi/bin/piSchoolBell/

$ list /home/pi/bin/piSchoolBell/

$ cat /home/pi/bin/piSchoolBell/gpio.service

$ cat /lib/systemd/system/gpio.service

$ list /home/pi/bin/piSchoolBell/gpio-scripts

$ cat /home/pi/bin/piSchoolBell/gpio-scripts/gpio-script

$ list /var/www/piSchoolBell

$ cat etc/cron.d/piSchoolBell

$ ps ax | grep gpio

$ /home/pi/bin/piSchoolBell/printToLcd.py -v

$ i2cdetect -y 1

$ cat /proc/driver/rtc