I made some internet connected 8 digit 7 segment LED displays using a NodeMCU and Harris semiconductor ICM7228A LED driver ICs the latter of which were salvaged from old aircraft avionics. As the chips would unlikely sell on eBay I decided to make them into a project and made a YouTube statistics counter. There wasn't much interest in that project but I was asked to make a clock only version so here is this project which is just a basic clock that connects to the internet and automatically sets the time. Nothing fancy; just a very accurate clock.
This version uses a 8 digit 0.56″ LED display and shows the current time by default which is obtained and set automatically by querying the NTP servers available on the internet. A button on the rear toggles DST on and off and DST mode active is indicated by the decimal point furthest to the right lighting up.
I fitted the completed PCB into a photo frame to complete the project and able to display it in my home. I have made full instructions available to download if you wanted to make one yourself and sometimes I will list a very limited number of completed or partially completed kit versions for sale on eBay which you can purchase by going to the links down below.
To sum up this unit is an universal 8 digit internet connected display which could be used for a number of things but in this example it is loaded with firmware to display the time from the NTP time service on classic 7 segment red displays. A photo frame completes the look.
The clock works by connecting to the internet through an ESP8266 WiFi module which has a 32 bit RISC-V CPU onboard running at 80Mhz with some spare flash space for user programs which can be programmed in C++ or Python. This is where the firmware for operation is stored. An ICM7218 display driver chip handles the multiplexing and display blanking and drives 8 common anode high efficiency displays directly without the need for current limiting resistors.
There is much more information on my blog at https://www.adrian-smith31.co.uk/blog/2023/04/youtube-statistics-counter-clock-fully-assembled-available-for-sale-again/
I'd recommend reading the setup instructions to see how the firmware works and how it connects to the internet. In a nutshell it broadcasts an SSID which you connect to with your phone and that will bring you to a web configuration page where you can scan for and connect to wireless networks in range. Once the configuration is saved the clock will remember it as it is stored in eeprom.
Setup instructions are here https://www.adrian-smith31.co.uk/blog/wp-content/uploads/2021/04/Instructions-clock-only.pdf