Process & Next Steps

I first built the circuit, wrote a single function to let the neopixels fade to red. After this function passed the test, I subscribed to a cloud function, converted the fading function to a responding function to that cloud function. Then I created the integration on IFTTT and let it trigger the cloud function. 

Challenges: I set an event happening 15 minutes later on google calendar for testing, but the IFTTT failed to catch that event and gave any response. I thought there are some problems with my setting and I checked many times but found nothing incorrect. In the end I found that the service will be triggered about 16 minutes before the event happens, not exactly 15 minutes.

I also found that there was a delay when the neopixels began to turn to red. But at last I found that it is because at first the color value in other two channels is so big (255), that the light color is nearly white, so although it is fading, it is hard to be distinguished by our eyes.