How many times have you had a disagreement with your coworkers about the air conditioner?
How many times did a signle person turn off the air conditioner for the entire lecture because he felt too cold?

The idiology behind our idea is democratic air conditioning - Every person in the room has a vote, every vote is equal, and the system decides the optimal temperature of the air conditioner based on the votes everyone cast, and the real temperature in the room.
Our solution is simple - an arduino device will be placed in each classroom/office/etc. and will be configured to work with the room's air conditioners.
Every person entering the room who has the ShAir mobile application, will be able to locate the bluetooth beacon connected to the device, allowing the user to register and vote on the room temperature.
Meanwhile, the arduino device will constantly query the server, checking if it needs to transmit a new command to the air conditioners - and if it does, will transmit the IR codes and change the temperature of the room!
The approach we took allows easy integration with existing air conditioners - installing the device is simple, only requires putting it in the room and configuring it through the administration site. No need to replace existing air conditioners or infrastructure.



Our project consists of three parts:

• • The Arduino device - measuring the temperature, sending telemetry and querying the server for instructions and sending the IR codes to control the AC. The device also has a bluetooth beacon assigned to it - which allows nearby users to locate and recognize it.
• • The Android app - detects the nearby bluetooth beacons, allowing the user to choose his classroom. When connected, allows viewing current air conditioner votes, real temperature, and for the user to vote on his own desired temperature.
• •The Server - Contains a database with all active devices, all user votes and to which device they belong, all the known air conditioners and how to operate them. The server decides for each device, upon request, which signal to transmit to the air conditioners, and communicates with the android app by handling requests and sending data.

The ESP8266 Adaruit HUZZAH Feather

At the Feather HUZZAH's heart is an ESP8266 WiFi microcontroller clocked at 80 MHz and at 3.3V logic. This microcontroller contains a Tensilica chip core as well as a full WiFi stack. You can program the microcontroller using the Arduino IDE for an easy-to-run Internet of Things core.

Infra-Red

IR radiation is radiation in frequencies outside the visible spectrum. IR is transmitted by all bodies that radiate heat. When you use any IR remote, for example a TV remote, an IR LED is used to transmit information to your TV by modulating the information on a frequency in the IR spectrum, and sending it to the TV IR receiver.

A common modulation scheme for IR communication is something called 38kHz modulation. There are very few natural sources that have the regularity of a 38kHz signal, so an IR transmitter sending data at that frequency would stand out among the ambient IR. 38kHz modulated IR data is the most common, but other frequencies can be used.

When you hit a key on your remote, the transmitting IR LED will blink very quickly for a fraction of a second, transmitting encoded data to your appliance:

By controlling the spacing between the transmitted modulated signals, the waveform can be read by an input pin on a microcontroller and decoded as a serial bit stream.

By controlling the spacing between the transmitted modulated signals, the waveform can be read by an input pin on a microcontroller and decoded as a serial bit stream.

How air conditioners remotes work

Unlike TV remotes, which have a signal for each button, and maybe a "repeat" signal for long presses, AC's remotes hold state - for example, when pressing + on the fan speed, not only the button id is transmitted, but also the fact that the AC is on, whether it's in cooling or heating mode, fan speed, temperature, whether the swing is on or off, etc.

Therefore, it's not enough to record every button on the remote once- you either need to record all the possible combinations that you will want to transmit, or you will need to understand how the remote passes information and construct the signal yourself.

Our board

The temperature module, TMP_102 was connected according to it's manual specifications: to the SDA anc SCL connectors of the board.
The LED was connected to pin #16.

Writing the code

The arduino code consists of a few seperated modules:

• • http_handler - This part is in charge of connecting to the WIFI network, and communicating with the server.
• •IR_handler - This part handles the IR communication - transmitting the code the server sends back.
• •TemperatureHandler - This part is in charge of cummunicating with the temperature module and extracring the temperature

The following open source libraries were used while writing the code:

• •ArduinoJson - Parsing JSON responses from the server
• •IRremoteESP8266 - Sending infrared signals with the ESP8266.
• •SparkFunTMP102 - Communicating with the temperature measuring chip

Each device stores it's own unique 'device key' which is a secret used to identify the device when communicating with the cloud, and used by the device admin to configure the device in the cloud(Location name, which AC it's connected to, etc.)
The IR codes are recorded separately and stored into the server database, so the end user device doesn't need to do that- only needs to choose the air conditioner model the device will use and nothing needs to change on the device itself - this is why the server sends the IR codes and they aren't stored locally on the device.

Android app documentation

Data managment

API Interacion

Libraries

UI structure