AutoConnect VS InfluxDB-Client-for-Arduino

And for Wifi management on ESP32, this awesome repo that "does it all": https://hieromon.github.io/AutoConnect/ -- this repo creates its own access point you can connect to with your phone to pop-up a "captive portal" (like you see at hotels or airports) to enter your own Wifi credentials -- this is only done once -- after that, the ESP32 will connect to the last known good Wifi network. If you don't want that, just use the built-in Wifi functions to create a local Wifi hotspot to connect to. Then creating web pages on the ESP32 is easy -- you can use the "PageBuilder" JSON syntax, or host regular HTML/JS/CSS files on the SPIFF/LittleFS partition and server those in response to incoming requests.

Or if you don't want to have a hardcoded ssid and password in your program, you can use the AutoConnect library

I want the device to be portable, so I want the esp32 to automatically reconnect to Wi-Fi every time I switch it off and back on. I have used this library, and it serves the exact purpose of what I want to do in my project : https://github.com/Hieromon/AutoConnect

I want to save power on a battery powered sensor but I also want to have AutoConnect set up to set up and configure the wifi. Since having the wi-fi running it can take up a lot of energy I would like to make sure that none of the battery is used during the programming set up. I was thinking that the AutoConnect would only run when it detects that it is plugged into a 5v usb port. I also want a switch so that the usb can power either the sensor (lower power) or the wifi configuration (high power) parts of the program. How would I best accomplish this?

It is this one right: https://github.com/Hieromon/AutoConnect ?

If each ESP has WiFi access, then you can post the sensor readings straight to a database. There are libraries available for the ESP32 that make it easy to upload datapoints to e.g. an InfluxDB database. You can visualize the data in a neat dashboard with software like Grafana. You could setup a Raspberry Pi or an old laptop/pc to run an InfluxDB and Grafana server, but there are cloud options as well. There are many guides and tutorials available for getting InfluxDB and Grafana running on your own machine, often with the intention to store and visualize sensor data from various sensors at home. Then you just have to write some code with a fitting library, e.g. this InfluxDB Client that sends the sensor readings to the database.

Use this https://github.com/tobiasschuerg/InfluxDB-Client-for-Arduino