Using two photons and a temperature sensor allows you to measure the temperature every five seconds in your car as it heats up or cools down. Connected with IFTTT and Google Sheets, a notification is sent to your phone every time the sensor reads within the target temperature zone set by the code. Results are graphed over time so that you can see how long it takes your car to reach the target temperature.
The photon reading temperature (Emma's Photon) follows the code and circuit schematic of the Particle Maker Kit Tutorial 4 - Temperature Logger. Additional code was added to this photon to allow for two way communication, where the temperature reading photon both publishes the measured temperature data and subscribes to the second photon (Dylan's Photon), which establishes the value of "above" or "below" the threshold temperature.
Dylan's Photon posts two events, "above" and "below". Emma's Photon subscribes to "below" since the goal was to cool the car down below seventy degrees, but you can easily change the subscription to the "above" event if the car is being heated up. Once Dylan's Photon posts "below" the onboard LED on Emma's Photon flashes (on for 2.5 seconds, off for 2.5 seconds). Since the events are posted every 5 seconds, the timing consistently represents two way communication and the speed of the cloud.
The only hiccup encountered with this project was the WiFi connection during the project testing. The poor connection to Niner Guest Wifi on the UNC Charlotte Campus made it difficult for IFTTT to graph the data on google sheets in real time from inside the car. The testing data was taken from the photon's Events Dashboard and graphed to represent the ability of this project to work correctly, although the live link to google sheets will show the inconsistencies in the data posted from IFTTT.
To view more information on this project and see how it works, watch our youtube video!