Help Button for Elderly People on the Arduino Platform

The design and implementation of a system capable of providing elderly people with a fast track to ask for help, remotely, to the person in charge of their care, using the cellular network is reported t. The main functionality is a help button, through which the person in charge of the elderly care will receive a text message when the elder presses the button. Recognizing the little connection between the people of this age group with cellular technology, defining the number to which the messages will be sent (and writing them) is not their task. The system has other features of great value, as a group of automatic alarms, also operating via SMS, generated by a group of sensors included in the system, which facilitates remote decision making from caregivers.


I. Introduction
Cuba is among the oldest nations in Latin America.It has 2,158,703 inhabitants aged 60 and over, representing 19.2% of its population, a figure that, according to experts, continues to increase in an accelerated way.
According to the priority that the Cuban State gives to the current problem of its accelerated population, the regular session of the National Assembly, took up the issue of supervision to repair, enlarge and equip elderly homes and grandparents' houses.
Hence, the State and health authorities design strategies and take actions to ensure that older people are healthier and enjoy a better life quality.Currently, the average survival in Cuba is 78.45 years (Fariñez, 2016).
The Universidad de Pinar del Río is involved in this process.So, in order to improve the life quality of the elderly, it has carried out some research aimed at automating some processes of their daily life.An example is this study, which pretends that the elderly, who are not familiar with the current technologies, can count on a system capable of, at any moment, sending a message to the person in charge of their care, just pressing a button.

II. Materials and Methods
As the main functionality, the proposed system responds to the need exposed, by interconnecting a button to the Arduino Uno programmable board on which a SIM900 GSM / GPRS Shield is already attached.This solution allows the person in charge of the elderly care to receive a previously defined SMS, once the elderly person presses the button, without having to write a text or define a number to send it.It should be noted that the process of defining the number to which the message needs to be sent is totally clear for the elderly.
In addition, the system is able to record several environmental parameters, such as temperature, humidity, and lighting, in order to improve the comfort of the elderly in the room.If any of these parameters are outside the defined range, an alert will also be automatically sent via SMS to the person in charge of caring for the elderly.
This system also allows the person in charge of the elderly care to know all the times and through via SMS, the behavior of each of the variables that are being sensed.After knowing these values, you can act on the equipment designed for the coupling of each of them, remotely, since a relay is used for the control of a higher-level power equipment.
La Universidad de Pinar del Rio no está ajena a este proceso, por lo que, en aras de mejorar la calidad de vida de los ancianos, ha realizado algunas investigaciones encaminadas a automatizar algunos procesos de su vida cotidiana.Un ejemplo de ello es el presente trabajo, con el que se pretende que las personas de la tercera edad, quienes no están familiarizados con las tecnologías celulares actuales -y por tanto, se les hace muy engorroso utilizarlas-, puedan contar con un sistema capaz de, en cualquier momento, con solo presionar un botón enviarle un mensaje a la persona encargada de su cuidado.

A. Arduino UNO programable board
The Arduino Uno (Figure 1) is a board based on an At-mega328 microcontroller.It has fourteen digital input / output pins (which four can be used for PWM [Pulse Width Modulation] outputs), six analog inputs, a 16 MHz ceramic resonator, a USB type female connector, a jack for power source, an ICSP [In Circuit Serial Programming] connector and a reset button (Guerrero, 2014).
The board has everything necessary to operate the controller (Figure 2), it is simply connected to the computer through the USB cable or an external power source, which can be an AC-DC adapter [Alternating Current -Direct Current] or a battery.It should be noted that, if it is powered through the PC USB, it is not necessary to connect to an external source.To program the board you need the Arduino IDE.
• Digital input / output pins: 14 (of which six are PWM outputs).
Arduino is a platform for free hardware and software.Therefore, it is possible to obtain its schematics and its design, and it also has some libraries that are quite enriched thanks to the fact that its community of programmers is growing.
La placa tiene todo lo necesario para manejar el controlador (ver Figura 2), simplemente se conecta al computador por medio del cable USB o a una fuente de poder externa, que puede ser un adaptador AC-DC [Alternating Current -Direct Current] o una batería.Cabe aclarar que, si se alimenta a través del cable USB en el ordenador, no es necesario que se conecte a una fuente externa.
B. Shield GSM/GPRS SIM900 GPRS/GSM shield SIM900 (Figuras 3, 4 y 5) es un escudo ultra compacto y confiable basado en el chip SIM900, 100% compatible con Arduino Uno y Mega.Puede trabajar en frecuencias GPRS/GSM de 850/900/1800/1900 MHz, para realizar llamadas de voz, envío de SMS y fax.Tiene muy bajo consumo de energía y un diseño muy pequeño con grandes posibilidades.Se controla y configura mediante un protocolo UART [Universal Asynchronous Receiver-Transmitter], usando comandos It is controlled and configured through a UART protocol (Universal Asynchronous Receiver-Transmitter), using AT commands.By default, the UART speed is set to 19200 baud.For this function it has a jumper, in order to select the digital pins through which communication is wanted (D0-D3); on the board there is a switch that allows to select between a UART connection or a debug port, which can be configured for the Arduino as well.The SIM900 can be connected directly to a PC through an FTDI232 chip.One of the most interesting functions is that it has a super capacitor with its own power circuit, which can operate as a RTC and give information about the date and time (PatagoniaTec, 2017).
The SIM900 card model that was used does not include the pins to set it up directly on the Arduino, but it will AT.Por defecto, la velocidad UART está configurada en 19200 baudios.Para esta función posee un jumper, para poder seleccionar los pines digitales mediante los que se quiere realizar la comunicación (D0-D3); en la placa hay un switch que permite seleccionar entre una conexión UART o un puerto de debug, que se puede configurar para el Arduino también.El SIM900 se puede conectar directamente a una PC a través de un chip FTDI232.Una de las funciones más interesantes es que posee un súper capacitor con su propio circuito de alimentación, capaz de funcionar como RTC y dar información de la fecha y hora (PatagoniaTec, 2017).
Para la transmisión de datos entre el SIM900 y el Arduino se utilizan los pines 7 y 8, así que, es necesario asegurar que los jumper de la tarjeta GSM están posicionados en D7 y D8, para activar estos pines (HeTPro, 2017).For the data transmission between the SIM900 and the Arduino, pins 7 and 8 are used, so it is necessary to ensure that the jumpers of the GSM card are positioned in D7 and D8 to activate these pins (HeTPro, 2017).

DHT22 temperature and humidity sensor
The DHT22 sensor (Figure 6) is created as a natural evolution of DHT11, with higher temperature and humidity ranges, and more accuracy.
The sensor can be found loose, with a white plastic "case" and four connection pins, or with the same white sleeve, but welded on a plate and with three connection pins, as well as a pull-up resistor (between 3-6 kΩ) and a filtering capacitor, normally 100 nF (Llamas, 2016A, García, 2014).
• Decimal resolution.Humidity and temperature values are numbers with a decimal number.
• Sampling time: 2 seconds, that is, it can only offer data every 2 seconds.
Regarding its benefits, reading temperature: • Range of values: from -40ºC to 80ºC.
• Response time: <10 seconds, that is, on average, it takes less than 10 seconds to reflect a real temperature change in the environment.
• Response time: <5 seconds, that is, on average, it takes less than five seconds to remark a change of real relative humidity in the environment (according to the tests, the air speed must be of 1 m / s for this affirmation).

Flame sensor
An optical flame sensor is a device that detects the existence of combustion from the light emitted by this one.

Sensor de llamas
Un sensor de llama óptico es un dispositivo que permite detectar la existencia de combustión a partir de la luz emitida por la misma.Esta luz puede ser detectada por un sensor óptico y ser capturada por las entradas digitales y las entradas analógicas de Arduino.Algunos sensores comerciales de este tipo se presentan en la Figura 7.
La llama es un fenómeno de emisión de luz asociado a los procesos de combustión.La combustión es un proceso que This light can be detected by an optical sensor and captured by the digital inputs and analog inputs of Arduino.Some commercial flame sensors for Arduino are shown in Figure 7.
The flame is a phenomenon of light emission associated with combustion processes.Combustion is a process that releases large amounts of energy in a heat form.During the reaction, intermediate compounds are generated that release part of their energy through the emission of light.
The spectrum of flame emission depends on the elements that intervene in the reaction.In the case products combustion with carbon in the presence of oxygen, two characteristic peaks are presented in ultraviolet, in 185nm-260nm wavelengths, and in infrared, in 4400-4600nm wavelengths (Llamas, 2016B).
Flame sensors are widely used in the industry.Many machines execute processes that are liable to generate flames, such as, example, machining or electro-erosion processes.Frequently they are carried out in the presence of combustible elements, such as oil or shavings.
Flame sensors are incorporated as safety devices that allow stopping the process in case of detecting any sign of combustion.These devices adjust to the wavelengths characteristic of the flame appearance and usually combine ultraviolet and infrared signals.
The electrical diagram is simple, the module is powered by connecting GND and 5V to the corresponding Arduino pins.Now, if you want to use digital reading, you can connect the DO output to one of the Arduino digital inputs; if you want to use the analog value, simply connect the AO output of the sensor to an analog input of Arduino (Prometec, 2016).

Magnetic sensor for windows and doors
The magnetic sensor for windows and doors (Figure 8) consists of a magnet and a reed switch (magnetic switch).This sensor works like a normally open switch (while there is a magnetic field).When the door or window is opened, the electrical circuit closes and it is possible to detect the respective opening.The sensor comes completely sealed in plastic which makes it extremely resistant ("Sensor ...", 2017).
The connection with other systems is made by cables that are previously installed in the sensor and that will have to be connected with a longer cable.The assembly on the door or window can be done desprende grandes cantidades de energía en forma de calor.Durante la reacción se generan compuestos intermedios que liberan parte de su energía mediante la emisión de luz.

III. Results
The implementation of the system, taking into account the characteristics and the interconnection of each of the components described with the Arduino UNO, is shown in Figure 9.
Besides the help button, its main functionality, the system has other great benefits.In the case of a group of alarms, also via SMS, fully automatic, which attends each of the thresholds values that are defined for each of the sensors used in the system: • When the temperature exceeds 32˚C and or decreases from 20 ˚C; • when the relative humidity goes out of the range between 40 and 60 percent; • when any of the doors or windows are opened; • when the light of the room changes its state; and • when some type of infrared component is detected, mainly fire.
Using the cellular network, through a text message, you can know the status of each of these variables, at any time: • Check the temperature and humidity value; • check the status of doors and windows; and • know if the light is on or off.
The system also facilitates decision making through a text message: • If the temperature or humidity are not at the desired value, an SMS can be sent to turn on the equipment that can affect these parameters; and • the light status can be modified, in order to influence the lighting parameter.

IV. Conclusions
The implementation of this system aimed at helping elderly people provides a fairly complete and fully functional prototype is obtained for its execution, by any person who needs to maintain control of the room parameters where there is an elderly person under his care and who can have a way to ask for help as simple as possible, including any home for the elderly or grandparents, taking into account that in this variant could change the platform of communication for a more economical one like Wi-Fi.

III. Resultados
La implementación del sistema, teniendo en cuenta las características y la interconexión de cada uno de los componentes descritos con el Arduino UNO, se muestra en la Figura 9.

IV. Conclusiones
Con la implementación de este sistema destinado a la ayuda de ancianos de la tercera edad, se obtiene un prototipo bastante completo y totalmente funcional para su puesta en práctica, tanto por cualquier persona que necesite mantener el control de los parámetros de la habitación donde se encuentra un anciano que este bajo su cuidado y que este pueda contar con una vía para pedir ayuda lo más sencilla posible, como en cualquier hogar de ancianos o casa de abuelos, teniendo en cuenta que en esta variante se pudiera cambiar la plataforma de comunicación por una más económica como Wi-Fi.