README.md

Battery voltage and MQTT

Build

Before compile, create configuration.h file with these lines (fill with your information, WIFI password, etc)

const char *ssid = "";
const char *password = "";
const char *mqtt_server = "";

Solar panel

Connect the solar panel to D32

+ -> USB
- -> GND

More details in G6EJD - Solar Power for Projects (Arduino/ESP8266/ESP32)

Components

• Lolin D32
• Solar Panel 80x100mm 1W
• Lithium Ion Battery - 850mAh

Free public MQTT brokers

• broker.hivemq.com

References

• G6EJD - David - Tech Note 130 - Solar Power for Projects (Arduino/ESP8266/ESP32)
• ESP32 MQTT – Publish and Subscribe with Arduino IDE
• 10 Free Public MQTT Brokers