This system was created to fulfill the requirements for the Spring 2018 MEGR 3171 Class.
The whole purpose of creating a temperature measuring device was to settle an on going issue between roommates on how hot one room in the house compared to another. One bedroom in the house always seems significantly hotter than the rest of the house. We have created a system that can have two sensors placed in different rooms and the temperature of the rooms will be recorded and graphed.
This project was completed by using two particle photons. Each photon was coded and wired similarly. In this project we used two separate temperature sensors, one sealed and one unsealed. This was selected so that if one wants to compare the inside temperature versus the outside temperature this could be done. When wiring the sensors a 4.7k ohm pull up resistor was used based on the spec of the temperature sensors. The sensors have three pins, a ground, a power, and a return. The ground was wired directly to the ground on the photon. The power and return were bridged with the pull up resistor. The power was then wired to the 3v3 pin and the return was wired to the D4 pin. The only difference in wiring the sealed versus unsealed sensor was determining which pin/wire was which. When wiring the sealed sensor, the red wire was power, yellow was return, and black was ground. Once properly wired, code was created that published the temperature data to the cloud. Once both photons were publishing data we used IFTTT in combination with google sheets to take that published data and input that into a google sheet and create a graph of the data. The graphed data is shown below. This data was recorded over roughly 12 hours sampling every one minute. This sampling rate can be updated in the code to publish at any given time.
This project also uses the subscribe feature. Each photon subscribes to the data that is published by the other. The photon then has a loop that runs every time the other photon publishes the temperature data. Once the loop runs, it illuminates the LED on the D7 pin, and after one second the LED is turned off. This was created to have a visual sight that the other photon is running and publishing data. This is useful so one doesn't have to pull up the console to see if both photons are publishing.
Below is a brief video that shows the general functionality of the Temperature Tester.
Below are pictures of the photons in the separate rooms doing work.