signpi

A subway arrivals sign using an off-the-shelf sign and a Raspberry Pi. Powered by the goodservice.io API.

The ugly part

Each time the display updates, the sign will display Load, ok ok, HC-1, and the display resolution. This process takes about 3 seconds.

signpi.webm

How-to

You will need

• A Raspberry Pi Zero W. These are unfortunately hard to get right now, but should be more widely available soon.
• A 192 x 32 LED sign with a HC-1 controller. These can be found on ebay, aliexpress, amazon.

Now, download the release zip: https://github.com/mdejean/signpi/releases/download/v0.2/signpi-0.2.zip

1. Insert your microSD card into the reader and open up rpi-imager. Choose Raspberry Pi OS Lite

2. Adjust the advanced settings, especially the wireless network settings. Uncheck the eject after complete option.

3. Write the microSD card.

4. Open up the 'bootfs' drive

   i. edit cmdline.txt: After rootwait add modules-load=dwc2
   ii. edit config.txt: At the bottom of the file, under [all] add a line with dtoverlay=dwc2
   iii. Rename firstrun.sh to firstrun2.sh
   iv. Copy signpi.deb and firstrun.sh to it.

5. Eject, put the microSD card in your Pi and plug it in to the sign.

6. Wait about 6 minutes for the first-run process on the Pi to complete. When it's done you should have a functioning sign, displaying northbound arrivals at Nevins Street.

7. To change the station, unplug the Pi from the sign and plug it into your computer. It will appear after 15-20 seconds as a flash drive. Open the config.ini file on the flash drive and edit the station. To find your station's code, go to https://goodservice.io/stations and click on your station. The station's code is at the end of the page's address. For example Nevins Street is https://goodservice.io/stations/234 so the code is 234

How it works

These displays allow the user to program the sign using some software which puts a file (COLOR_01.PRG) on a flash drive which is then plugged in to the sign. signpi makes the Raspberry Pi Zero W pretend to be a flash drive containing that file, and 'unplugs' itself once a minute to get the sign to display the image it has created.

License

Except as otherwise noted, this software is distributed under the terms of the GNU General Public License, version 2 or later. See LICENSE for the full text.