DEPRECATED

The new version of crosswalk can be found at https://github.com/iwsmith/crosswalk_v2

crossXwalk Sign

This repository holds the code and configuration for running a Raspberry Pi to power one of the crossXwalk signs.

Concepts

The crossXwalk can run in a number of different modes. The modes determine the sign display, audio, and interactivity.

• off - no display or sound
• demo - run one of the demo programs shipped with the LED drivers
• image - display a single image on loop
• walk - main crosswalk interaction mode

When in crossing mode, the signs will react to button presses by generating a scene, composed of an intro, walk, and outro animations. The signs then synchronize and start playing the scene together. Once the scene is over, the sign returns to a standby 'halt' image.

Raspberry Pi Setup

Start by assembling the hat by soldering all connections. Once that is complete, ensure you have run the Adafruit setup scripts to install the drivers for the RGB Matrix plus Real Time Clock Hat.

Log into the pi and set things up, note you may need to use a virtual environment on modern OS versions. The commands below are a simplified overview.

# Upgrade and prepare for Ansible management
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install python

# Download and install drivers
$ wget https://github.com/adafruit/Raspberry-Pi-Installer-Scripts/raw/main/rgb-matrix.py
$ sudo python3 rgb-matrix.py
# Answer (2) for Adafruit RGB Matrix HAT + RTC
# Answer (Y) to enable realtime clock support
# Answer (2) for the 'convenience' optimization level

# Build the image viewer tool
$ cd rpi-rgb-led-matrix/util
$ make led-image-viewer

Deployment

Run ansible from your development machine to configure the host and deploy the code:

$ ansible-playbook site.yml -i inventory.ini [-l crosswalk-x] [-C] [-D]

Content

Creating New Voice Commands

On a Mac say -v Samantha "Walk Sign Is On. Walk Now." --data-format=LEF32@22050 -o walk_now.wav

Creating gifs in Photoshop

Using Photoshop's timeline, create a frame animation. Timing for each walk is set using the frame delay. Even single images need at least two visually distinct frames (for whatever reason, the the software doesn't respect the frame delay if there are two identical frames). Most walks have two frames, one with a dark grey pixel in a corner, and a delay that matches with the length of the audio. Loop count should be set to "Once" in the timeline.

In the config file, the loops attribute should have a value of 1.

Moving to HQ Mode

1. Move the button from pin 18 to pin 19 on the HAT
2. Solder a jumper wire between pin 4 and 18. See this diagram
3. Reinstall the drivers (see above), this time selecting option one in the last step (quality). Make sure you wget the latest script, don't just re-run what's on device.

Improving Quality

echo "isolcpus=3" >> /boot/cmdline.txt

Scheduling

In config.yml we define walks and schedules for when they run:

walks:
  chimchim:
    category: ad
    loops: 1
  gif-dots:
    category: inactive
    loops: 10
    audio: trip.wav

The above defines a walk called chimchim, that is in the ad category and loops only once. It also defines a walk called gif-dots that is in the inactive category, loops 10 times, and plays the audiofile trip.wav. By default walks will attempt to play a sound file matching their name (e.g. chimchim.wav). Similarly the gif that is played will be chimchim.gif.

Weights

Weights are used to set how often walks from a given category are played. By default all walks have a weight of one. You can specify a custom weighting scheme as seen below for demo. Any category not explicitly listed in a weighting scheme will use the default.

weights:
  all:
    _: 1
  demo:
    actions: 18
    actionscharade: 7
    actionsplus: 20
    ad: 0
    airguitar: 2
    animals: 11
    animalsplus: 8
    dance: 10
    fin: 0
    game: 1
    karaoke: 2
    language: 7
    normal: 7
    normalish: 7
    rare: 2
    rps: 2
    silly: 11
    sleep: 0
    social: 10
    trip: 0

Menu

The menu section allows you to define an active weighting scheme by time. The scheme that is the most recently set will be active (that is, the start time is in the most recently passed). In the below example the demo weighting scheme will be activate after 1:45 AM on August 1st, 2021.

menu:
  - start: '2021-08-01T01:45:00'
    weights: demo

Schedule

You can also schedule a walk to play at a specific time. In the below example the workoutWednesday walk will play at 2100 on July 6th, 2019. Ads are automatically generated and run in the hour preceding the event to let people know what's happening and when. The ad_prefix is used in some sort of generation of this ad.

schedule:
  - time: '2019-07-06T21:00:00'
    label: workoutWednesday
    ad_prefix: workout