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A simple and eye-catching Dot Matrix Clock/Calendar showing also temperature and Humidity with a practical 3D-printed enclosure

This is a very simple yet large Dot-Matrix Clock-Calendar running MD_Parola library. Many friends seen this clock in my garage and in my Instagram stories: they liked a lot so they convinced me to publish the project here even if a Dot Matrix Clock is nothing new for most of us.

I’ve (very slightly) redesigned the standard font and designed a simple enclosure. I wrote some info here too for making the library used in this project more understandable since probably is not the simplest one for driving led matrixes: it has a lot of features and effects (it manage sprites too!).

So, even if this clock is something you already seen a lot of times, probably you’ll read something new and you’ll have some more clues.

This clock is based on a NodeMCU (ESP8266) so WiFi is used for setting the right time from a NTP server without user intervention. I’ve used a NodeMCU Lolin having dimension of about 31x58mm: this exact model (it has the CH340 as UART/USB adapter) is only needed if you want to 3D-print the enclosure I designed and provided here, otherwise you can use whatever you have in your drawers having an ESP8266 on it. The NTP solution is very simple and gives the more accurate results (but obviously you need the WiFi, this can be the only drawback maybe). Time is kept using the TimeLib library by Paul Stoffregen: this library gives also an easy access to time variables making the whole program easier to manage and update. A DHT22 sensor is used for showing temperature and relative humidity too. I perfectly know this sensor is not the most accurate one and will have a drift during the years but is one of the most used, cheap and available.

Data are showed on n°8 8x8 led matrix displays: first 4 displays are static (meaning that are not used scrolling effects here) and shows the actual time (hours:minutes with the time separator flashing). A second block of 4 displays shows day of week, date, temperature and relative humidity by scrolling them from right to left.”

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