Use the USB to charge battery

Ultilize the USB charge function, the user can build a USB/solar power bank for outdoor sport

application. Charge the battery with solar panel by daytime and USB at night with cell phone charger

(if it is available). User can also charge small charge current, low power devices, such as smart band

or Bluetooth headset with the USB OUT.

Use USB charger to charge Li battery

Build a low power environment monitor station

This application example use the BME280 environmental sensor to record temperature, humidity

and atmospheric pressure, VEML7700 ambient light sensor to record the the ambient illumination,

and DS1307 RTC module to record time. Use the analog input A1 to monitor the battery voltage

(equivalently the battery capacity). To achieve lower power consumption, use one Arduino digital IO

pin to turn ON the OUT1 power supply, read all the data from the sensors and turn them OFF. Cycle

this pattern for a proper interval T to reduce the average power consumption. This can completely

get rid of the quiescent power of the peripheral modules. Although single peripheral may consume

little power, it can be considerable large for a number of them. This module provides users with

effective methods to drive the peripheral modules into discontinuous (pulse) mode to achieve low

power operation.

Low power environment monitor sta

         https://www.dfrobot.com/wiki/index.php/Sunflower:_Solar_Power_Manager_SKU:_DFR0535 5‐25‐18