piring v3

Control a school sound system from a Raspberry Pi with touchscreen

• OS: RaspiOS (based on Debian 11 Bullseye and beyond)

Usage

ring

Hardware and pinout

Raspberry Pi with 3.5" 480x320 touchscreen and a relay that controls the power to the amplifier, and a audio lead from the pi's output to the amplifier's input, so that apart from ringing the various school bells, alarms can be sounded and announcements can be made. The relay is powered from the 5V pin(2) closest to the corner and ground by the pin (39) closest to the opposite corner. The signal pin (37) is next to the ground pin.

Function

The Normal schedule will ring on every weekday, unless that day is marked as a No-Bells day. Special schedules will always ring on any day they are scheduled, but then the Normal schedule will be cancelled, unless at least 1 of the Special schedules is an Additional schedule (having a + after the date in file $ringdates). The (optional) file $ringdates lists the dates for the Special & Additional schedules and for the No-Bells days (Saturdays & Sundays are No-Bells days by default). The time schedules are defined in the file $ringtimes. The touchscreen can be used to turn on the amplifier to make an announcement or play (alarm) sound files.

• The input files $ringdates and $ringtimes are read from the same directory as where the $ring script resides, the $buttons script is in subdirectory $touchscreen together with all images that are part of it, and all the sound files reside in subdirectory $soundfiles.
• The input files $ringtimes and $ringdates are read and checked for proper syntax & semantics.
• The ringtone sound files referenced in $ringtimes are symlinks R.ring in where R is the digit referenced (0 is the default ringtone); when referenced they need to be present in $soundfiles.
• The optional (alarm)button sound files are symlinks B.alarm (B:1..4) which are played when the corresponding touchscreen buttons are selected.
• The temporary file $state also resides in $touchscreen and it is used to pass the touchscreen state that is generated by the python script $buttons (which is started from the $ring script).
• When all is in order the program starts and output is logged to stdout.

Format inputfiles

• All lines starting with # as the first character are skipped as comments.
• $ringtimes: lines with HH:MMsR where s is Schedule (Normal schedule is space/empty, and Special schedule codes have an alphabetic character) and R is the numerical single digit Ringtone code. If R is space/empty it references the default ringtone file 0.ring. If R is - it means that time slot is muted regardless of any other schedules. In general, the R (numeric) refers to the ringtone file R.ring. All characters after position 7 are ignored as a comment.
• $ringdates (optional): lines of YYYY-MM-DDsP or YYYY-MM-DD/YYYY-MM-DDsP where s is either space/empty (for No-Bells dates) or the alphabetical Special schedule code. The P can be empty/space (replace the Normal schedule) or + (in addition to the Normal schedule). The double date format is the beginning and end of an inclusive date range. There can be multiple Special schedules for the same date, and all get rung (even if that date is also a No-Bells date!). All characters after position 12 resp. 23 are ignored as a comment.

Required

raspi-gpio coreutils(sleep fold readlink) sox(play) date [$buttons: python3-pygame] [installation: tmux(optional)]

Deployment

See file INSTALL

License

GPLv3+ https://spdx.org/licenses/GPL-3.0-or-later.html

splay

Play sound files over the amplifier

Usage

splay [<file> ...] if no is given, 0.ring is played