₹1000(approx $14 USD) PPG Signal Based Heart Rate Calculator and Temperature Display Using Arduino Uno and Android OS

* Arduino UNO
* Bluetooth Module HC-05
* Batteries 9V
* 16x2 Lcd
* Prototyping board
* ua741
* Resistances
* Capacitors
* Led -red
* 7805 voltage regulator
* IR led
* IR receiver (Phototransistor)
* Wires
* Bug strips
* 28 pin dip IC socket
* 16 Mhz crystal oscillator

The amplifier system is basically a signal conditioning as well as gain providing system. At first it is required to remove the DC component of the input signal by using a high pass filter with frequency 0.8 Hz and then pass it through an amplifier with suitable gain and again pass it through a low pass filter which removes high frequency components of the signal from the sensor. Set it's frequency to 3Hz. Now again provide some gain according to requirements and the feed the signal to the digital input pin 8 of Arduino.

The sensor module consist of one heart rate calculating sensor that's on the finger and a temperature measuring sensor on the wrist.

Just type in as shown in the image.

I used a mobile handset box to assemble all the components and some cardboard to create chambers for battery storage, LCD, Circuit boards etc and a layer of foam to separate all of them to prevent any short circuit.

I did a little short cut here. Rather going for complex programming i used mit app inventer 2 to develop my android application. Here is a screenshot of the blocks i used.

Just adjust the potentiometer to calibrate it against any standard heart rate measuring device.