My team and I designed Reminichair (a smart wheelchair) for old people who live far away from their families. Due to their busy lifestyle and hectic schedule, the working adults don't have time to stay in touch with their old parents or relatives. Therefore, we designed this smart wheelchair, which would establish a sort of connect by sending regular updates about their whereabouts and well-being to the old person's family members.

We installed a GPS module in the wheelchair for tracking the location of the elderly. There is also an emergency button which sends a message to the relatives' phone when pressed. Heart rate sensor and temperature sensor would monitor the health of the person. All these updates can be sent by tapping a button on the app to at most 5 relatives.

Step 1: What You Need

Rectangular box

Glue gun

Bread Board

Black Tape

5 V Battery

White paper (A4)

Push Button

LM 35

Buzzer

Some Resistors

Double Sided Tape

Step 2: How to Begin

First, configure the push button, and send a message to a mobile phone. When the button has pressed a Buzzer is alarmed so that neighbors could hear if any emergency arises.

Then, we tested the temperature sensor. It was working perfectly, but it heated up a lot as we connected it to the 5 V supply. At first, we thought that the better temperature sensor would suffice for showing proper values of temperature without heating up Then heart rate sensor was tested. We detected the pulse by the fingertip. Then, we merged the code of push button and temperature sensor. After that, we merged the code of heart rate sensor, which was actually a pretty daunting task. At this point in time, we realized that the HC05 Bluetooth module would not be enough for the three sensors to work together. Therefore we went for the HC06 module which could transmit all the three separate values together.(heart rate, temperature, push-button signal). Simultaneously, GPS was also being tested. Initially, we were using loose wires(without connector pins), so we had to first go and attach connector pins to the wires. Then too, the GPS sensor was giving strings separated with questions marks and other characters. It was perfectly fine when we were testing it outside of a closed room.

Step 3: Connect to the Breadboard

This is the connecting you are supposed to make on your breadboard.

Step 4: Schematic and PCB Design

In case if you want to fabricate you PCB you can use this file for the same.

circuitreminichair.fzz
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Step 5: Code

This is the code for the temperature sensor and pulse sensor along with push button and HC 05

codefile.ino
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Step 6: Android Application

This is the android app that we have made. It basically links various sensors like pulse sensor and temperature sensor with the Bluetooth of your android device. App interface has been shown in the picture.

codefile.aia
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Step 7: Testing

Here we are testing the temperature sensor, pulse sensor, and GPS Co-ordinates. We are also testing whether this information is being transferred to another android device via SMS.

Step 8: Problems You Might Face

1. Bluetooth module-- HC05 will not transmit the values. HC06 is required as it can transmit more amount of data.

2. GPS module not working properly-- Showing required values combined with question marks and other characters. GPS module works perfectly when tested outside the room.

3. Broken Pipe error-- Loose connections.

4. Heart rate sensor showing abnormal behavior. Running for the same code successfully once, and failed afterward, even though connections were proper.

5. Problem in merging code for all three sensors into one single Arduino.