I've been working on a smart humidity sensor project that demonstrates the current ThingSpeak and IFTTT workflow. The project uses two ThingSpeak channels and two MATLAB Analyses to send users a notification when the room is too dry or too humid.
I used a NodeMCU ESP8266 programmed with the Arduino IDE to take readings from an Adafruit DHT11 sensor and upload them to the first ThingSpeak channel. The second channel is populated with data from a scheduled MATLAB Analysis that calculates the ideal indoor humidity using outdoor temperature data from the MathWorks weather station.
I've written a tutorial on Hackster.io detailing the steps I took to create the project. If you're just looking to see how to trigger IFTTT from ThingSpeak, feel free to jump to parts 4 and 5c of the story.