Tested with WeMoS D1 Pro (ESP8266) and ESP32 Dev Module.

[cxtal]

Greetings! Here is a short summary of changes that should fix #8 , #4 , addresses some concerns for #5 and perhaps makes #3 somewhat easier to deal with:

• move configurable parameters to the top of the file and add sections.
• turn some configurable parameters into defines rather than variables.
• change from DyanmicJsonDocument to StaticJsonDocument in order to suit arduinojson v6
• allow the user to switch between SSL and plain HTTP (for private servers)
• fix deep sleep support for ESP32 and ESP8266 (ESP8266 is now compatible)
• remove yield() in the main loop since it is redundant
• rename GROUP_NAME -> FAMILY_NAME since that is what is implied (find3 terminology)
• fix defines to include BLE only on ESP32
• fix a startup crash on ESP8266 (wait for WiFI connection)
• use proper NTP client to retrieve timestamp and remove getUnixTimestamp (now compatible with both ESP32 and ESP8266)
• add the UTC offset as a parameter to the NTP client
• shorten the chip ID and add "esp-" to make it clear what device is updating the find server
• use toggle defines rather than "is defined" since it is more elegant for the user to deal with

We have checked with a WeMoS D1 Pro (ESP8266) and an ESP32 Dev Module and both architectures seem to work flawlessly now. I do realize that there are quite some changes but it's a single file so not much one can do. In any case, we have a copy on our development wiki so if you just want to nitpick and keep the things you like and throw away what you do not like, please feel free to do so. Or feel free to just merge! :)

WeMoS D1 Mini Pro with 4MiB (4MiB, 2MiB FS, 1019KiB OtA): 
Sketch uses 282144 bytes (27%) of program storage space. Maximum is 1044464 bytes.

ESP32 Dev Module with Minimal SPIFFS (1.9MB APP / 190KB SPIFFS) and with BLE enabled:  
Sketch uses 1494282 bytes (76%) of program storage space. Maximum is 1966080 bytes.

Very nice sketch and solves a lot of issues with finding cheap, expendable and low-power hardware for FIND3! All thumbs up and many thanks for your contribution! :+1:

[cxtal]

More on #8 - I think this should be left as being optional to the user since it does not seem like a developer choice. Oh well, what's one more #if going to harm? :sweat_smile: Perhaps a follow-up commit.

[kabili207]

I tested this with the TinyPico using the Minimal SPIFFS partitioning and it worked quite well. The only change I had to make was on line 150, where I increased the buffer size from 256 to 4096. I live in a dense residential area and smaller buffer was not enough to include all of the wifi APs nearby.

RAM:   [==        ]  17.8% (used 58332 bytes from 327680 bytes)
Flash: [=======   ]  71.4% (used 1403178 bytes from 1966080 bytes)