Method 1: As far as I know the pulse goes from 1ms to 2ms (1.5ms is middle position). It should be possible to "analogify" or mathematically say "integrate" the PWM signal using a R-C combination on the input pin and read the voltage from this. But the voltage level will be low due the duty cycle which goes from approx. 1:20 (1ms/20ms) to 1:10 (2ms/20ms). From 5V full scale you read 0.25V to 0.5V. You may add an analog OPAMP amplify it to 5V. This method will slow down the reaction time a little bit

Method 2: Before doing the Method 1 it may be less effort to write it in Arduino and use either a PWM read library or use a interrupt to measure the pulse width. You can also read the low time to determine if the input signal is valid or not eg. to detect signal loss.

Method 3: This is the simple but ugly workaround! Add a small Servo to your signal and drive a potentiometer which ist then read by the M5 analog input.

If you compile the example WiFiAccessPoint then it means the Atom turns into a WiFiAccessPoint. If you entering the same SSID and PW as your home Wifi then it means you are creating an additional access point on the Atom with the same name as the existing one. This may be confusing. The IP Address of 192.168.4.1 is the local address of the Atom now. Change the SSID on the Atom to something else to avoid the confusing.
To connect your Atom to the existing wifi you need a WifiClient sketch or any firmware like UIFlow that has one included. After connection to your home Wifi the Atom gets an IP Adress from your home DHCP Server which is running on the Wifi Router in most cases. This should be one in the 10.0.0.xxx range if this is your home network.

Ok, I see you want to poll the data instead of push.

Blockly, which is great for simple projects or quick test of a sensor, seems to lack of many functions. It is also not very comfortable for extensive projects and you are required to use a cloud service to edit your code or you have to use a very old desktop version with even less functions. My oppinion about that.

I prefer the Arduino environment. There are many libraries and examples including web servers.
It means a bit more of text coding and less drag&drop but copy&paste from examples work for me well.

EZData is just one of the possible data storages. With M5 products it is very easy to use. It is also possibe to use other cloud services. Cloud means "some storage somewhere on the internet". It requires a connection to the internet anyway.

Some ideas:

• Use a separate non interupted connection such as LoRa or mobile internet for your battery measurement. Depends on what is possible at your location and what/how you need to communicate.
• log to a cloud like storage in the local network, powered by battery on mains loss. No access during power loss but all data saved
• Detect the internet connection loss and log to SD card until the connection is back, then upload all missing.

Prüfe die serielle Verbindung zwischen dem StickV und dem Gray. Möglicherweise stimmt da die Verdrahtung nicht (Rx/Tx vertauscht).
Falls das nicht hilft, würde ich am StickV eine Debug-Zeile einfügen die auf dem Bildschirm ausgibt was über die serielle Schnittstelle ankommt (es soll ein "/" sein). Am besten gleich unterhalb von Zeile 35 (if data[2] == "/" :).

Check the WiFi frequency band. ESP32 is only compatible to 2.4GHz WiFi networks. Some iPhone use 5GHz by default but there is a compatibility mode for switching down to 2.4GHz.