Preliminary source code is up at github - https://github.com/alphacharlie/ESPx-Chronograph

Also - finally Starting on the Mark IV version. I've got the timer code working well on the ESP8266 and have recently received some new BPW-34 photodoides. The Mark IV design is an open trap design. Since we're using the ESP8266 which has wifi, I'm also building a web interface into the chronometer. This will allow display of multiple readings and averaging of readings and settings menu.

The first open-trap design will experiment with translucent plastic sheet to diffuse natural sunlight and with LEDs to illuminate the trap area actively to see which works better as a trigger.