There were two main goals of this project. The first was that we wanted to be able to read the temperature with an accuracy of at least plus or minus 3 percent. The second main goal was that we wanted to be able to open the garage door with our phones. With these two goals combined we decided to place one photon with the temperature sensor on it in the garage and the other photon inside. Once the garage hits a certain temperature, it will notify the other particle and the on board LED will turn on. This will notify us that it is warm enough in the garage to go get in our car.
A major benefit of wiring the particle as shown in this photo, is that there is no code required. To trigger the garage door opener, turn the D1 sensor to HIGH on the Particle app and it will open and close the garage door.
We bought a space heater that has a timer. At a predefined time, the heater will be turned on and the garage will begin to heat up. The window on the car is also rolled down, which will help heat the car as well. This aspect of the project was just an added bonus. It has started to get pretty cold in the morning and I'm tired of facing the brisk cold before my car heats up.
For the particle that needed to be outside, an antenna was attached in order to pick up on the wifi from inside the house. The BME280 sensor is connected to the particle, check the circuit diagram for a more clear understanding. This particle is to be powered by a battery brick, which requires a certain amount of current to be drawn in order to stay on. A diode was attached to keep the battery brick on.
The graph below is from ThingSpeak.com. The plateau in the beginning is when we had the sensor inside. the initial increase in temperature is when I placed my hand over the sensor. The massive drop in temperature is when we took the particle outside to the garage. Then the gradual increase in temperature is when we turned the space heater on in the garage.