Blog 2 - HRV

 Blog 2 - HRV
Brendan Mayer

This sensor uses a simple optical technique called PPG to track changes in blood volume as it moves through
your body. It works by shining an LED light onto your skin—some of that light is absorbed, and some bounces
back. A photodiode in the sensor picks up the reflected light and uses it to calculate your heart rate.
By analysing how the light absorption changes over time, the sensor can measure your heart rate and variations
in it.

Heart Rate (HRV) Sensor



Micro:Bit and MakeCode


To take readings from the micro:bit, I connected it to a breadboard, which made it easier to hook up the heart rate sensor. Using block coding in MakeCode, I was able to collect the data and display it in different ways—either as an LED signal on the micro:bit itself or as a graph in the debugging menu.





Challenges:


The main challenge faced was getting an accurate reading from the sensor, since I drive a motorcycle my hands would always be cold and have less blood flow to my fingers making the values of the readings very small. I found that the amount of pressure you put on the sensor also has an effect on the readings as well as movement. The ideal scenario would be a light amount of pressure with warm hands and no movement for an accurate reading.



Conclusion:

In conclusion, I learned a lot about micro:bits and connecting external devices through a breadboard
I had to research the serial blocks in MakeCode in order to get the serial debugging to work and I learned
here is a lot you can do through radio and serial outputs from the micro:bit and is mainly how you can
connect to other devices wirelessly.

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