This is universal board for ESP8266 (chip ESP12 from AI-Thinker) the board is designed for using (optionally) with LiOn\LiPo charger based on TP4056 and DW01 , DS3231 time chip and bunch of different I2C devices.You can built as solar\battery devices as regular powered devices with battery support(like uninterruptible ).

The device can sleep most of the time then wake up periodically for sending information and fall asleep again. Current consumption starts from 20ua in deep sleep mode and drawns about 75 ma in wifi mode.

You can use a wall charger (DC 5V out) for feeding the device instead of solar panel. You can use LDO 3.3V for providing stable voltage and check the value over A0 (analog input) of ESP8266 .

This board was born as a continue work on wifi Air Environment sensor and wifi Soil Moisture

The board designed for working with Mike Polan's software Am Server(AM Manager) https://sites.google.com/site/mppsuite/. It intended to measure Soil humidity and temperature and send figures over wifi network.

Is a "Sleeper-device" (battery powered or solar powered) to read a sensor I2C soil moisture meter (https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/ has made by Miceuz from Catnip electronics.) with ESP8266 (12F) soldered on my design PCB board. It wakes periodically to report the sensor value, wifi is disabled until needed, and fall asleep.

Sure the device can work with other Iot automatisation systems like Espurna , Tasmota, ESPHome and etc.

(https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/