fall detection and prevention system

I am making a fall detection system for my project using accelerometer sensor of a smartphone. Using the sensoduino android app i am able to transfer the sensor readings from the smartphone to the arduino via the HC-05 bluetooth module. I need guidance on how to proceed further in this project. once i have received the values what should be my next step. i am totally new to arduino. Also if someone has worked on this before so can anyone please help me with the code too. I need to implement a fall detection algorithm which involves comparing acceleration vector sum value to a particular threshold value above which a fall is detected. How to decide the threshold value? thanx in advance :slight_smile:

What purpose does the Arduino serve? Surely the smartphone can detect a fall.

Most accelerometer chips have a 0g ouput. Its used for detecting freefall

I wonder if the phone can send data to the Arduino fast enough for the Arduino to be able to do anything about a fall other than know that it happened?


@jremingtom Well yes a smartphone itself can detect a fall but i wanted to do a both hardware and software related project so had to use an arduino.

Is this a school / college project? It's cropped up in the past and I suspect that Google may be able to help you locate what people have done previously.

@robin2 Have a look at this link :

This is what i have implemented for my project.

@dannable It's a college mini project that i am doing. I searched for previously done work in such projects but mostly people have used an adxl accelerometer rather than using a smartphone sensor. Some had used gyroscope and pressure sensors as well. I am just planning on using an accelerometer sensor. I wish to know once i get correct readings from the smartphone onto the arduino what should be my next step. Also, once the fall is detected i am planning to send an sms to the emergency contacts of the person fallen using a gsm module. I am totally new to this concept of arduino and gsm module ! Also how to decide the threshold value for comparison?

@robin2 Have a look at this link :

It would take a long time to read it all. At first glance it does not seem to address my earlier question.


Have you tried a SW-420 Motion Sensor? It is used for detecting earthquakes. I have never used one my self, but I bet that its information could be graphed and used to detect large movements (ie, a fall) and determine the severity of the fall. Its just a suggestion, but I would do lots of research on it before any actions toward one of these sensors. Also, you could probably make it into a dongle to put on the phone (possibly).

@rooster1420 Actually i need to use a smartphone sensor only, but anyways thanks for your suggestion. Maybe i can try to implement this idea for my next semester project. :slight_smile:

So in short, you don't need an Arduino and are desperately trying to figure out some way of involving a totally unnecessary component.

:astonished: :astonished: :astonished:

@paul Yeah :stuck_out_tongue: that's right, but i will be showing the output by a blinking LED i.e if a fall is detected the LED would start blinking , also a buzzer will start to ring and if it's a minor fall the person can reset and stop the LED from blinking. Though i know it's quite lame to use an LED and buzzer even when i can use the smartphone vibrator for the same purpose, but i want to use an arduino anyhow. Well there many arduino projects that can be done without the use of an arduino but still people use it for learning purpose and that's what i am doing.