In several of my previous projectsI  have presented ways to make weather stations, but this time I decided to make it a specialized device with a strictly defined purpose. Namely, at least in my experience, the basic weather information for planning any activity in the coming days is whether there is a chance of rainfall in that period. Unfortunately, in commercial, and even most DIY weather stations, this information is either not available at all or is quite brief in the form of a current day rainfall forecast. That's why this time I decided to create a specialized weather station with the purpose of providing detailed information about the possibility of precipitation in the current and next five days.     

 For this purpose, data from openweathermap is used where you can create a free API key. The display shows the predicted amount of precipitation in mm, the time of day in which it is predicted, as well as the percentage probability of rain on a specific day. Specifically, in this project I used the CrowPanel ESP32 4.2” E-paper Display module with built-in ESP32S3 MCU. It is very practical in the sense that there is no need to connect components and solder, and it has multiple IO ports, a microSD slot, multiple buttons, and even a battery charger circuit. 

Don't miss the PCBWay Christmast Big Sales from November 28th to December 31st. Get free christmas coupons and Redeem or check value a promo code. You ca also start with a PCB Order for Only $5. Up to 50% off for 3D printing & CNC Machining and Special Sales in PCBWayStore! PCBWayhas all the services to create your project at the best price.
   At first glance, you can see that I didn't pay special attention to the visual part of the display, in the sense that there are no advanced graphic shapes and images, but only rectangles that represent the days, so the required information can be determined very fast and easily.

   Now let's explain how it works and describe the information displayed on the screen.
- In the upper left part of the screen there is the basic information about the current weather. In the first line we have descriptive information about the weather condition, then the temperature in degrees Celsius with one decimal place, then the air pressure value and the air humidity expressed in percent. Next we have the label UT (Update time) which tells us at what time the data was last downloaded.

- In the upper right part there is a space where the current situation regarding rainfall is indicated, as well as the forecast until the end of the current day. The space is divided by horizontal and vertical dashed lines. The vertical ones show the time (24 hours) midnighth, 6AM, noon, 6PM and midnight. The horizontal lines serve for a more precise orientation for the predicted rainfall amounts in mm. The numbers on the left edge show the value of this parameter. It is very important to emphasize that for better visibility this value is variable and depends on the maximum amount of precipitation in a 3-hour period, which is predicted for that day. 

So as I mentioned, the amount of precipitation is predicted at a distance of 3 hours and is expressed through vertical bars. At the top is the day of the week as well as the POP symbol, which in translation means probability of precipitation and is indicated in the unit Percentage.
- The lower half of the display contains the forecasts for the next 5 days of the week. Analogous to the previous description, the day is indicated at the top, and the POP value in percentage at the bottom. The amount of precipitation is expressed on the far left, but now the maximum value is dinamicly adjusted depending on the maximum predicted amount of precipitation throughout the next five days.

 Now in this case each day is divided by four horizontal and two vertical lines. The horizontal lines serve for a more precise visual assessment of the amount of precipitation,...