This project is a purpose-built display based on a 64x32 LED matrix and an ESP32. The code can be easily adapted for other purposes, and includes code to fetch web requests, store config, etc.
I have made three displays so far: one that shows the current London Tube departures for my local station with data from TfL, one that shows planes flying over my house with data from Flightradar24 based on this project, and one that shows network statistics for my Unifi-based home network.
Full photo album here.
- Fetches JSON data from an API at a given interval
- Parses the JSON and displays it
- Brightness controlled by MQTT
- "Party Mode" / Screensaver mode, turned on and off by MQTT
- WiFiManager-based hotspot for configuration
- 64x32 P4 LED Matrix (from here)
- D1 Mini 32 (any of these)
- Optional: Brian Lough's Shield PCB (you can wire it yourself instead, but these are much neater) (from here)
- 24V PSU (up to 35W per display) (I picked this one for 3 displays)
- LM2596 Buck Converter to step down to 5V (from here)
- Two-core cable, Wago connectors/screw connectors, etc.
- 6x M3 12mm bolts, 16x 3mm short countersunk screws
You can just use a 5V power supply instead, but 100W+ ones tend to have loud fans in them, which is annoying, whereas my 24V 120W PSU is completely silent. It also helps with voltage drop if you're using long cables.
See the files in the Enclosure folder for the STLs of the two 3D-printed parts of this project, as well as the full Fusion 360 model showing you how it all fits together and what wood is required for the project.
These options are available across all three displays:
- Hostname - what your device will show up in your router admin console as (can't contain spaces, etc)
- MQTT Server - the IP or domain name of your MQTT server
- MQTT Port - defaults to 1833
- MQTT Username
- MQTT Password
Set the room name (in the format living_room for example) in the web config interface, along with your MQTT server and port, etc. This will become the base of the topic when combined with the MQTT_NAME of your device in mqtt.h. Then the device will:
- Publish on
room_name/MQTT_NAME/mqttconnectedordisconnectedas a last will and testament - Listen on
room_name/MQTT_NAME/infor messages in JSON format (e.g.{ "brightness": 160 }and will fade to the new brightness - Listen on
room_name/statefor messages in JSON format (e.g.{ "party_mode": "chill" }(orofforon)
Find your TfL Stop ID here. TfL treats tube stops and bus stops the same, so if you provide the correct route and stop ID, it will work for both.
Config Options:
- TfL Stop ID
- TfL Route (e.g.
northern,circle,H91,9), you can test your route here - Direction (options are
outbound,inbound, or empty for both)
Use Google Maps or similar to find the longitude and latitude of the top left and bottom right points that define the area you want to monitor flights inside.
Config Options:
- Flight Area in the format
51.5672,51.4131,-0.4146,0.1107(for example)
Unlike the other two, this one requires a PHP script running on a web server (because Unifi needs 3 different API requests to fetch the info I wanted to display, and also Unifi returns JSON payloads that are too big to fit in the RAM of the ESP32).
Install the GlowingSquare/Unifi/web/ files on your PHP server, and rename the config.example.php to config.php, filling in the necessary details as outlined by the code comments. Test that your server is working by visiting it in a web browser with ?width=64 appended to the URL to check you can scrape data correctly.
Config Options:
- Script URL as set up above, e.g.
http://10.0.1.9/glowingsquare/?width=64
This project was just started as a passtime during the 2020 COVID-19 lockdown as a bit of fun, happy to take questions but this isn't a long-term open source kinda deal, I'm just open-sourcing an already completed thing.
People have asked me if I'll be selling these, and I'll consider it and come up with a rough price estimate. It's a lot easier if you don't bother with the nice enclosure, which takes roughly 30% of the cost.