LED weather station with NTP clock and calendar

Colleague efi22 wrote in one of the posts:

I have an AURIOL station (once bought in LIDL), but it has the inconvenience that you have to approach it and make interesting readings up close. Additionally - it measures temperatures only inside and outside (I ignore other readings). I have a need for measurements in several places and I was looking for something suitable.
Intrigued by the topic, the station itself, the aesthetics of its performance, the possibility of measurements from several sensors and the visualization of measurements on LED displays (they ensure good visibility during the day and night), I decided to make this station.
When I made this decision, I was not aware that it would be so time consuming.
Without the help of a friend efi222 it would take even longer. He was very willing to help with the construction of this station, not only substantive, but also suggested many practical solutions. Thanks a lot.
The very launch of the receiver and measurement modules was not a major problem. On the other hand, the assembly and commissioning of the display board was quite a challenge. But thanks to the help of the author - it was possible to do it all.
My station looks like this:


I encourage you to repeat the station (the more so that you can count on the author's help) - the visual effect catches the eyes of visitors - and the satisfaction with doing it yourself is enormous.

Hi,
Very nice design, nicely made and generally interesting. I wonder why you use DS18b20 and an integrated temperature and hygro sensor - not easier on one (SHT30 or DHT22?).
Isn't it nice if the station had an eCO2 and TVOC measurement - as it is already such a combine . If you are interested, see my entries on CCS811 . greetings
Zbyszek

Hello
Congratulations on your perceptiveness ...
The topic of DS18B20 was also raised by my colleague @Gienek , when he was building this station. In fact, the HTU21D sensor has a pretty decent temperature measurement. I gave the DS18B20 a little off the beaten track. I use them a lot and that's why it probably turned out that way. After a bad experience with DHT11 (it's more like a toy), I focused on looking for a humidity sensor with good parameters and a good price. I chose the HTU21D.
Friend's station @Gienek measures the temperature with this sensor (small changes in the transmitter code). Maybe he will say how these "thermometers" work in practice.
The design was mainly about a legible panel and I think it worked. You can always expand the project with additional measurements.

Knowing the capabilities of the HTU21D chip, I thought that the use of additional DS18B20 was unnecessary. That's why I asked a colleague efi222 o changing the software and enabling temperature measurement with HTU21D. As different temperature sensors have different measuring accuracy, a software change was made in an attempt to check the accuracy of the measurement. After checking with the "mercury reference thermometer", it was found that the difference in the readings with the HTU21D was not greater than 0.2 ° C. With this result, the test software remained final
The station has been operating for over two months and, to my satisfaction, it is working perfectly.