Make a large homebrew LED display for Network Caller ID

NCID Display

B Tod Cox writes in, “My wife wanted to be able to know who was calling without having a phone nearby or going to look at a tiny caller id box. So, I started with John Chmielewski’s NCID (Network Caller ID) project on sourceforge and ported it to the Raspberry Pi. This was not a necessary development step, but the process got me well acquainted with debugging and testing new stuff with NCID. I had tinkered with Arduinos and stumbled across the red LED matrix panels sold by Adafruit; combining them with NCID led to the creation of NCID Display. I would be remiss to not mention that John Chmielewski was a huge help on both the porting NCID to the Raspberry Pi and the development of NCID Display.

In addition to the main webpage for NCID Display, we have a page with a bill of materials and detailed assembly instructions:

Thanks so much for sending in this great project!

NCID Display is a homebrew NCID (Network Caller ID) client designed for easy viewing of telephone calls and short messgaes within a room.

Perfect for:

  • Viewing the Caller ID of the current or last call:
  • Viewing complete or partial text messages
  • Viewing Calls or Messages from different Sources:
  • View incoming calls or messages from multiple gateways; your home phone, iPhones and Android phones! (see the NCID project page for list of supported gateways)


  • Support for 4 to 6 Adafruit LED Matrix Panels. Four Panels is the standard configuration for 2 rows x 16 characters
  • Reads call log upon connection to NCID server and stores recent history.
  • Displays the following information, if provided, by a NCID server:
    • Messages (MSG:)
    • Outgoing calls (OUT:)
    • Smartphone notifications (NOT:)
    • Smartphone caller id (PID:)
    • Hangup calls (HUP:)
  • Display brightness can automatically brighten with incoming call or message and automatically dim after preset time.
  • Debug mode(s) to send information to serial monitor (compile time option).

See more here.

Featured Adafruit Products!


16×24 Red LED Matrix Panel – Chainable HT1632C Driver: These LED panels take care of all the work of making a big matrix display. Each panel has six 8×8 red matrix modules, for a 16×24 matrix. The panel has a HT1632C chip on the back with does all the multiplexing work for you and has a 3-pin SPI-like serial interface to talk to it and set LEDs on or off (you cannot set the LED to be individually dimmed, as in ‘grayscale’). There’s a few extras as well, such as being able to change the brightness of the entire display, or blink the entire display at 1 Hz. Read more.

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