Stainless Steel Wi-Fi Word Clock
by aidenvigue in Circuits > LEDs
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Stainless Steel Wi-Fi Word Clock
Hey! I'm a sophomore at Purdue and I've always been fascinated with word clocks since I first saw the QLOCKTWO at an art gallery in New York.
I believe that the ability for a seemingly random grid of letters to tell the time is magical.
Most of the commercially-available ones, however, only tell the time in five minute increments, opting instead to use a "four corners" system in which LEDs on each of the corners indicate how many minutes to add onto the time displayed in words. While this makes the clock simpler, I wanted one that had minute by minute resolution, just by using words.
I wanted to have it controllable over WiFi and to be able to automatically adjust for daylight savings time.
Supplies
For the PCB, you'll need:
- 256x Worldsemi WS2812-5050
- 256x 0603 100nf ceramic cap
- 2x 0603 5.1k smd resistor
- 1x 0603 10k smd resistor
- 1x ESP32S3-WROOM-1 module
Hardware:
- 4x M3 7mm bolts
- 4x M5 5mm bolts
- heat set inserts (4x M3, 4x M5)
Front Plate:
- You'll need access to a powerful laser cutter to cut out the front metal plate. I used a Fablight FL3000 and I chose to use 1.2mm brushed stainless steel. Minimum recommended stock size is 13"
- However, you could also 3D print the front plate or order it from a site like Ponoko.
Design PCB
The clock's main electronics all reside on a single PCB with the lights.
I designed it in Altium Designer. It's a 16x16 grid of addressable LEDs that are controlled by an ESP32-S3. I spaced the LEDs out to a grid of approximately 16mm to fit with the stainless steel panel.
The board source files and gerbers are available at https://github.com/acvigue/wordclock2-pcb
Order PCB
Upload the Gerber files to your board house of choice. I used JLCPCB and I was very happy with how they turned out.
I ordered 5 of the boards along with a solder stencil, and it was about $85 including shipping fees. I still have a few boards left over.
Assemble PCB
Place and solder the components down onto the PCB according to the BOM and CPL files. Alternatively, you can opt to have JLCPCB assemble the front (LED) side of the circuit board and it would make this step a lot easier.
I used solder paste and a hot air rework station as I ended up folding the stencil on accident.
Design & Manufacture Front Panel
I wanted the front panel to look very modern, so I opted to laser cut it out of stainless steel. I designed it in Adobe Illustrator and used the same font that is used on the QLOCKTWO clock, DIN.
While I had manufactured the clockface myself, I went ahead and priced it out online on Ponoko.
Downloads
CAD & 3D Printing
I exported the PCB as a STEP file and imported it into Fusion 360 to work on the structural case for the clock. I also designed clear diffusers to ensure that the letters are evenly lit. The case screws onto the PCB with 4 M3 heat-set inserts, and attaches to the front panel using 4 M5 heat-set inserts.
The case also has a hook on the back for wall-mounting the clock using a nail.
Firmware
The clock runs a custom version of WLED, with a usermod specifically written for this clock.
The Git repository: https://github.com/acvigue/WLED (branch: clocks)
You can clone the repository and choose the PlatformIO environment "WORDCLOCK2-S3" to compile and flash the firmware over the USB-C port on the PCB.
Testing & Finishing Touches
At this point, the clock can be joined to your Wi-Fi network by following the regular WLED setup instructions. It's a good time to test that all the LEDs work as expected by running an effect, and if they do, then go ahead and set the time. Screw on the front cover, and you're done!