Inspired by your use of the ESP-01’s, I bought a few to play with. I have just released a new version of both of my “SmartThings” and “ST_Anything” libraries (v2.1) that support using the ESP-01 as a WiFi module for an Arduino MEGA. Next step will be to see if I can actually run my ST_Anything library directly on the ESP-01 the way I can with the NodeMCU v1.0 ESP-8266-12e boards.