Progress with Light Sensor Concept (Week 12 Continued)

In a previous post, I played with code and created a Particle function that made LEDs flicker like a candle whenever the function was called. While experimenting, I had the idea of creating a flickering paper circuit fireplace, or a candle, that might be triggered by data connected to a light sensor.  Ultimately, I wanted to figure out a way to do this as a step toward creating a wifi-connected book containing artwork brought to life with real-time data.

1.  ThingSpeak channel documenting light sensor             2.  Photon connected to a paper circuit

Unlike the Goofy Photon Servo Notifier which used the Particle.subscribe feature (linked to data in my Google Calendar) the function illustrated below is triggered via a web hook that I set up in ThingSpeak, which only calls the function if a sensor on another Photon reports a low light level.

PROOF OF CONCEPT (Video demo)

I'm making progress toward my goal of creating a wifi-connected book that uses data to help tell a story. As a test of concept, I created a Thing HTTP app and a "React" app in ThingSpeak to trigger a Particle function (on one Photon) based upon readings from a Photocell (attached to a second Photon).  To get started, I created a ThingSpeak channel and a Particle web hook by following this tutorial.

Once I created the web hook, my Photon started logging the photocell data on ThingSpeak. In order to make the data more useful, I modified the Photon code in the tutorial by adding the following lines to the loop, just above the line containing the Write API key for the ThingSpeak Channel.)

value = map(value, 0, 4096, 0, 255); //maps values
value = constrain(value, 0, 255); //constrains values between 0 and 255.

Next, I uploaded this code to a second Photon, connecting the Photon to a paper circuit using alligator clips. Lastly, I created the ThingHTTP and React apps.

The React app allowed me to set up a trigger related to the data. I set it up so that a reaction happens any time the sensor picks up a value of 150 or greater (when it's cloudy or dark and the resistance increases). The ThingHTTP app allowed me to post an HTTP request to Particle, triggering the Particle function that illuminates the owl's eyes and the candle flame.