NYC Subway Time LED Matrix Display

Overview

Capabilities

• Display times for arriving trains at any NYC subway station
• Rotate through time displays for multiple stations
• Image of display
• Video of display
• Disruptions Screen

Materials

• Raspberry Pi (Pi 3 Model B or later recommended) with internet access over ethernet or WiFi
  • Do not overclock it (can cause screen issues)
• SD Card (8GB Class 10 or better)
• LED Matrix. I used this Adafruit one, which is 64 x 32 with a 5mm led spacing
• Adafruit RGB Matrix driver. I used this one with the RTC, but you should be able to use the regular one.
• Adequate power for the display and Pi. This adapter should work great.
  • It's worth noting that my display is configured with 2A to the hat and 500mA to the Pi over USB. It works using lower brightness, but there is some flicker.
• Appropriate peripherals (Display, keyboard, mouse, etc) or SSH enabled by default.

Before You Begin This Guide

• Install Raspbian (No desktop environment needed)
• Keeping the default user "pi" will work best, as that is what's configured in packageinst.sh
  • You may still change the default password
  • If are advanced and you wish to use a different username, modify packageinst.sh for the new paths.
• Enable SSH
• Get an MTA API key here.
• Install Python 3 (likely installed by default) and PIP (you likely will need to install) on the Raspberry Pi (For retrieving packages)
• Follow this Adafruit guide to get the examples running on your display.
  • You can pick between quality and convenience, both work for the purposes of this guide.
  • Ensure that you are able to run example 0 (the rotating cube) before continuing.
  • If the display works for a second and then shuts off, you may not have sufficient power.
  • If there is severe aliasing or flickering, experiment with different values for --led-gpio-slowdown. I used --led-gpio-slowdown=2

Creating the display

• At this point, I'm assuming that you have the rotating cube demo file working. Your file structure should look like /home/pi/rpi-rgb-led-matrix/bindings/python/samples/
• We will be keeping this file structure during this guide for the sake of simplicity.

Transferring Files

• Move the files rundisplay.py , mtacalls2.py (be sure to add your API key in the two places) , stops.csv , and packageinst.sh to /home/pi/rpi-rgb-led-matrix/bindings/python/samples/
  • Using FileZilla over SFTP is the reccommended way to do this.

Installing Python dependencies

• In your SSH window, change directory to our main directory
  • cd /home/pi/rpi-rgb-led-matrix/bindings/python/samples/
• Run packageinst.sh (You may need to make the file executable using the command below)
  • sudo chmod +x packageinst.sh
  • sudo ./packageinst.sh
• Check your work. You should see lots of new folders in the /home/pi/rpi-rgb-led-matrix/bindings/python/ directory.

Running the code

• First, make rundisplay.py executable
  • sudo chmod +x rundisplay.py
• Then, run the code (Modify this code as needed for your display).
  • sudo ./rundisplay.py --led-rows=32 --led-cols=64 --led-slowdown-gpio=2 -b=30
• You should see train times appear after a few minutes of the code running. You should see the times appear on your terminal window as they are loaded by the API as well.
• If this works, jump to the customization section. If not, follow the troubleshooting section.

Troubleshooting

Basic Troubleshooting

• Ensure whatever file you are trying to run is executable
  • sudo chmod +x filename.abc
• Ensure all python packages are loaded
• Ensure you entered your API key probably
• Recheck whether you can run the rotating cube demo file

More Advanced Troubleshooting

• edit mtacalls.py using nano to add the below line:
  • print(totalstationtimes("A41"))
• then, run mtacalls.py
  • sudo python3 mtacalls.py
• you should see train times print out after a few seconds. If you don't, and you see a python error, search the error on stack exchange.

Customization

• Use stops.csv to find the code for your desired station(s). Use only the first three letters.
  • e.g, 232 for Borough Hall, or A41 for Jay St-Metrotech.
  • Note that the station names for some stations in stops.csv have been shortened to fit better on the display.
  • Ensure to change the data links on line 10 of mtacalls.py if your station is not on the 1,2,3,4,5,6,A,B,C,D,E,F,M
  • You may also need to edit the c value in lines 140 and 142 of rundisplay.py to reflect the number of stations if you are not using 3.
• Modify the time filter for how long it takes you to get to your station (change mintoarrival on line 51 of mtacalls2.py)
• Modify the font - I like the font spleen. Change on line 56 of rundisplay.py
• Edit /etc/rc.local to make the display start on boot and run continuously
  • See example rc.local file
  • I also recommend creating a cron job that reboots the pi automatically every day. This will help with stability.