It seems to be very similar to the ITead Sonoff B1, so it's based on that.

* Works with many different ultrasonic sensor models: HC-SR04, SRF05,
  SRF06, DYP-ME007, JSN-SR04T & Parallax PING)))™.
* Built-in digital filter method ping_median() for easy error correction
  (use SONAR_ITERATIONS build flag to configure).
* Allows setting of a maximum distance where pings beyond that distance
  are read as no ping or clear (use SONAR_MAX_DISTANCE build flag).

This Module has an ESP-07 on it with only 1MB Flash!

*new platform 1.7.3
* changed remaining upload_port/upload_flags to get values from ENV ota.py

fix some extra_script typos: missing curly bracket & duplicate.

- Added new environment 'nodemcu-geiger' to platformio.ini.