Hexascroller

Hexascroller is the large, hexagonal LED display in the middle of the front room. It ordinarily displays the current local time and Internet Time (in @beats).

Hardware overview

Hexascroller is composed of six 60x7 LED panels. Each pair of panels is controlled by a single Teensy 2.0. Power is supplied to the panels from a PSU that can be switched on and off by a relay attached to a single Teensy (so we can put Hexascroller in low-power mode if we wish).

All three Teensies are controlled by the Home Assistant Raspberry Pi in the mezzanine, using a Home Assistant add-on. The Pi has its own dedicated 5V power supply. The three Teensy 2.0s are connected to a powered USB hub.

Software overview

All software and firmware for Hexascroller can be found in a git repository hosted at [1]. The "hexascroller" directory contains the Arduino sketch that runs on the Teensy 2.0s; the "hexaservice" directory contains the software that runs on the Pi.

Connecting to Hexascroller

Hexascroller runs as a Home Assistant add-on. The logs can be viewed in Settings -> Add-Ons -> Hexascroller -> Logs.

If something goes wrong

• Check if the add-on is running in Home Assistant. Check the logs.
• Restart the add-on
• Restart the teensies by unplugging and replugging the USB hub in hexascroller, then restart the add-on.

MQTT protocol

MQTT topics hexascroller subscribes to

• hexascroller/power/set: set the power state of the display.
  The payload should be "ON" or OFF"
• hexascroller/invert/set: set the invert state of the display.
  The payload should be "ON" or OFF"
• hexascroller/message: set the message to display.
  The payload should be a string of text to display. Easter egg: the tilde character `~` shows the Resistor logo.

MQTT topics this service publishes

• hexascroller/power: the current power state of the display.
  The payload will be "ON" or OFF"
• hexascroller/invert: the current invert state of the display.
  The payload will be "ON" or OFF"

The service also publishes an availability topic:

• hexascroller/available: the availability of the service.
  The payload will be "online" or "offline"

Extending the font

The font is an Nx7 pixel png bitmap. Black elements represent pixels in the character; white elements are blank space. Red pixels (255,0,0) are the character delimiters. If you're adding a character, you'll also need to add it to the inventory string in the conversion script (convert-font.py in the Grab-Bag/Hexascroller directory). To generate the font itself, run convert-font like so:

./convert-font.py >hexascroller/hfont.c

This will regenerate the hfont.c file that contains the converted font data. We keep hfont.c checked in, so be sure to run this after making your modifications.

Obsolete information

Too old to be useful; too charming to delete altogether. Note that Hexascroller no longer has audio capabilities!

Old Protocol

This is the old protocol; it may not apply to anything!

Hexascroller accepts newline-terminated strings.

Any string that does not start with an exclamation point is considered a "message" and is scrolled for approximately a minute before timing out.

Strings that begin with an exclamation point are "commands" which modify the behavior of hexascroller. Commands can include scroll speeds, wipe types, default messages, etc.

Commands

format	function	implemented?
!s[STRING]	Set default message to STRING	Yes!
!d[udlr][SPEED]	Set direction and speed of scrolling.	Yes!
!b[hz]:[duration]	Attention beep	Yes!
!tNOTE[,NOTE...]	Play a tune (see below)	Yes!
!S	Get hexascroller's current status	Yes, currently the message
!Dr	Read the current date in the format YY/MM/DD HH:MM:SS	Yes
!DwYY/MM/DD HH:MM:SS	Set the current date in the format YY/MM/DD HH:MM:SS	Yes
!A[messsage]	Emit the given message at 9600 B on the third UART; these will be routed to the LED strip controller	Yes
!C	Set clock mode	Yes

Tune format

Tunes are expressed as a series of notes of the format: [octave][note][duration], seperated by commas. Notes with the value "r" are rests. For example, here's a recognizable tune expressed as a tune command:

t3e4,r1,3e4,r5,3e4,r5,3c4,r1,3e4,r5,3g5,r15,2g5,r5

Sharps and flats are expressed by appending '#' and 'b', respectively. "2c#" is a C-sharp, and "3bb" is a B-flat.

Song repository

SMB !t4e5,4e5,r6,4e5,r6,4c5,4e5,r6,4g5,r42,4c5,r12,3g5,r12,3e5,r12,4a5,r6,4b5,r6,4a#5,4a5,r6,3g5,4e5,4g5,r6,5a5,r6,4f5,4g5,r6,4e5,r6,4c5,4d5,4b5,r12,4c5,r12,3g5,r12,3e5,r12,4a5,r6,4b5,r6,4a#5,4a5,r6,3g5,4e5,4g5,r6,5a5,r6,4f5,4g5,r6,4e5,r6,4c5,4d5,4b5,r24,4g5,4f#5,4f5,4d#5,r6,4e5,r6,3g#5,4a5,4c5,r6,4a5,4c5,4d5,r12,4g5,4f#5,4f5,4d#5,r6,4e5,r6,5c5,r6,5c5,5c5,r30,4g5,4f#5,4f5,4d#5,r6,4e5,r6,3g#5,4a5,4c5,r6,4a5,4c5,4d5,r12,4d#5,r12,4d5,r12,4c5,r54,4g5,4f#5,4f5,4d#5,r6,4e5,r6,3g#5,4a5,4c5,r6,4a5,4c5,4d5,r12,4g5,4f#5,4f5,4d#5,r6,4e5,r6,5c5,r6,5c5,5c5,r30,4g5,4f#5,4f5,4d#5,r6,4e5,r6,3g#5,4a5,4c5,r6,4a5,4c5,4d5,r12,4d#5,r12,4d5,r12,4c5,r42,4c5,4c5,r6,4c5,r6,4c5,4d5,r6,4e5,4c5,r6,4a5,3g5,r18,4c5,4c5,r6,4c5,r6,4c5,4d5,4e5,r48,4c5,4c5,r6,4c5,r6,4c5,4d5,r6,4e5,4c5,r6,4a5,3g5,r18,4e5,4e5,r6,4e5,r6,4c5,4e5,r6,4g5,r42,4c5,r12,3g5,r12,3e5,r12,4a5,r6,4b5,r6,4a#5,4a5,r6,3g5,4e5,4g5,r6,5a5,r6,4f5,4g5,r6,4e5,r6,4c5,4d5,4b5,r12,4c5,r12,3g5,r12,3e5,r12,4a5,r6,4b5,r6,4a#5,4a5,r6,3g5,4e5,4g5,r6,5a5,r6,4f5,4g5,r6,4e5,r6,4c5,4d5,4b5,r12,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,5a5,5a5,r6,5a5,4g5,4f5,r6,4e5,4c5,r6,4a5,3g5,r18,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,4f5,r6,4f5,4f5,4e5,4d5,r6,4c5,r42,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,5a5,5a5,r6,5a5,4g5,4f5,r6,4e5,4c5,r6,4a5,3g5,r18,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,4f5,r6,4f5,4f5,4e5,4d5,r6,4c5,r42,4c5,4c5,r6,4c5,r6,4c5,4d5,r6,4e5,4c5,r6,4a5,3g5,r18,4c5,4c5,r6,4c5,r6,4c5,4d5,4e5,r48,4c5,4c5,r6,4c5,r6,4c5,4d5,r6,4e5,4c5,r6,4a5,3g5,r18,4e5,4e5,r6,4e5,r6,4c5,4e5,r6,4g5,r42,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,5a5,5a5,r6,5a5,4g5,4f5,r6,4e5,4c5,r6,4a5,3g5,r18,4e5,4c5,r6,3g5,r12,3g#5,r6,4a5,4f5,r6,4f5,4a5,r18,4b5,4f5,r6,4f5,4f5,4e5,4d5,r6,4c5