SMD component (74HC154D) eliminated in latest hardware design. Easier to solder with improved reliability.

I had started a wiki page on additional information related to the build. Please check it out if you have the kit.

This is a web synchronized clock featuring 24 characters and 12 characters 14 segment LED displays, allowing spelled word time display options, plus various numeric character sets. The clock offers various display format and options. Ad-hoc message can also be post to the clock unit via a built-in web server. Script integration (ex. curl) can easily be done to expand usages.

A single tactile button is used to advance one of the eight present display formats / messages. The same button when press-n-hold allows cycling between various display transition effects.

A countdown timer can also be activated via double tapping the button. Setup is done via a web interface that allow for 8 preset display formats / messages.

By itself, S14Clock shows time and other preset messages. With it's built-in web interface, scripts can be created and expand it usage such as stock tickers, POS display, weather forecast, etc. This is an open source PlatformIO / Arduino project that can be cloned or expanded into other projects.

Please refer to the S14Clock github project page for detailed setup and operating instructions.

Main Features

• Web based WIFI setup, upon initial usage.
• Web based configuration, to preset up to 8 display formats or messages.
• Date time formats via strftime() c library standard.
• Ad-hoc message via web page posting.
• Synchronize date time via ntp.org time server.
• Various setting including automatic cycling of messages, alternate numeric symbols, etc.
• Employs ESP32 S2 Mini, with open source code via my github repository.
• Future firmware update by user via webtools.

Technical Details

• Employs Arduino ESP32 AutoConnect library for entering WIFI credentials.
• Full use of ESP32 S2 Mini IO pins to perform LED multiplexing.
• Access of IO registers directly and timer interrupts for efficient multiplexing.
• S14-24 dimension 200mm x 32mm x 30mm, 100g.
• S14-12 dimension 100mm x 30mm x 30mm, 50g.
• Both units consumes about 100mA at 5V.
• Power via USB-C, power supply and cable not included.
• V3 hardware design introduced since July, 2023. 74HC154D line decoder eliminated via additional charliplexing on top of segment multiplexing.
• V2.02 firmware able to auto-detect all versions of hardware, including V3, V2 12 and 24 characters.

Before You Order

This is a parts kit and will require soldering and assembly, if you do not posses the tools and skills to construct it, select the "assembly" option. All parts are DIP through holes, there are no SMD parts to solder.

Two versions of 12 (S14-12) and 24 (S14-24) characters were created, with same functionality. This product is the 24 character version.

Both S14-12 and S14-24 units have red LED modules. S14-24 has dimmer display as the multiplexing frequency is half that of the 12 character version. Both units display intensity is adequate for indoor use.