This code, run on an ESP-01/ESP-01S/ESP8266, joins a WiFi network and responds to ICMP pings. That's it.
I use it to monitor whether a certain power strip at home is powered on or off.
[env:esp01] in platformio.ini is configured to build & run on a 1M ESP-01S board. Note that the board setting is esp12e, per this post. I have confirmed this works correctly on my particular ESP-01S.
MIT; see LICENSE in this repo.
Chris Dzombak