We can save energy by deep-sleeping the ESP32. During this time, the chips do not consume a lot of energy but also are not responsive. This is why Espressif included a mysterious Ultra Low Power core (ULP) which is active when the main processor sleeps. People say it has to be programmed in Assembler, and nearly nobody was able to program it in the Arduino environment.
Until now.
Links:
Arduino IDE ULP repository: https://github.com/duff2013/ulptool
Sketch: https://github.com/SensorsIot/ESP32-ULP-Arduino-IDE
ESP32 module: http://s.click.aliexpress.com/e/bQwDCLQs
ESP32 Board: https://s.click.aliexpress.com/e/_Dn2tPEf
ULP commands: https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/ulp_instruction_set.html
Technical Reference: https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf
Otii power Supply: https://www.qoitech.com
Supporting Material and Blog Page: http://www.sensorsiot.org
Github: https://www.github.com/sensorsiot
My Patreon Page: https://www.patreon.com/AndreasSpiess
Alternative: https://flattr.com/@andreasspiess
My Bitcoin address: 19FSmqbBzb5zsYB1d8Bq4KbxVmezToDNTV
If you want to support the channel, please use the links below to start your shopping. No additional charges for you, but I get a commission (of your purchases the next 24 hours) to buy new stuff for the channel
For Banggood https://bit.ly/2jAQEf4
For AliExpress: http://bit.ly/2B0yTLL
For ebay.com: http://ebay.to/2DuYXBp
https://www.facebook.com/profile.php?id=100013947273409
https://twitter.com/spiessa
https://www.instructables.com/member/Andreas%20Spiess/
Please do not try to Email me or invite me on LinkedIn. These communication channels are reserved for my primary job