short-term weather forecast system

The author is located in an area with a lot of convective weather and hot and humid weather. I stared at it silently, going in and out five or six times a day to dry the clothes, and my mind was racing, what is the weather forecast on the mobile app? Weather warning text message? It can only be regarded as a late report. Ji Cao was lazy, doing things by himself, and had plenty of food and clothing. He recalled the proverb that he often heard when he was a child: Swallows fly low and it will rain. Then, after letting the dog out for a while, he learned a sentence: high-pressure divergence, low-pressure convergence. The general meaning is that a drop in air pressure indicates that bad weather is coming. On the contrary, good weather is coming. The greater the slope of the pressure change, the more drastic the weather change will be. Pan it! Then came this stitching monster (work), which actually wanted to predict the possible weather conditions within a few kilometers of the surrounding area.

The outDoor end is placed outdoors, regularly collects air pressure and humidity data, and transmits it everywhere through Bluetooth broadcasts. The indoor end is placed indoors, and continuously scans surrounding Bluetooth devices to obtain the broadcast data of specific devices, and then analyzes and predicts the weather and sends it to the screen for display. Here outDoor and inDoor do not perform Bluetooth connection, but only transmit data through Bluetooth broadcast data in a certain format. Similar to a beacon.

Based on the characteristics of RSL10, it is designed for outdoor solar power harvesting: a combination of BQ25570 + 3v solar epoxy board + 70F farad capacitor. Through the configuration of the feedback resistor, the capacitor charging voltage is set to 3.8v, and the power supply voltage of the rear stage is 1.8v. Sunlight at noon Under sufficient conditions, the charging current is about 20mA. Weather data from BME280 air pressure, humidity, and temperature are collected every 180 seconds, and then a powerful broadcast is performed at intervals of 40ms for 6 seconds. The measured average current is less than 12uA, and the 70F lithium-ion capacitor can maintain With a battery life of more than 80 days, as long as it is not in extreme night conditions, it should be able to continue working until it breaks down.

The indoor end is relatively simple: a combination of 1200mAh lithium battery + charging and LDO circuit + three-way buttons + eink screen. I originally wanted to do some interactions through the three-way buttons, but the display speed of the eink was really unbearable, so I gave up. The indoor device will be configured to scan at intervals of 100ms, with a scanning window of 50ms, continuously. The measured average operating current is about 1mA, and the estimated battery life is about one month.

In fact, this kind of short-term and small-scale weather forecast system is often used in some special fields, such as civil aviation airports. However, more meteorological parameters are considered, and a deeper understanding of the meaning of various meteorological parameters is required.
The project author himself thinks that the Outdoor side is barely usable. If a small blind can be used, the weather data may be more accurate. However, there are certain regrets in the design of the Indoor side, such as the performance of the eink module, RSL standby processing, etc., which should be The standby time can be further improved. In addition, the weather prediction is just a completely out-of-the-box process, and it uses the most basic changes in air pressure to make rough predictions. There are also many factors such as humidity changes that are not taken into account. In fact, if you think about it carefully, maybe build an MPU. , the whole machine learning algorithm, RSL10 is purely responsible for data collection, and broadcasts it to the MPU for calculation, which may have better results.

If you want to communicate with the author of the design work, you can go to the work release post: http://en.eeworld.com/bbs/thread-1171837-1-1.html