I need to get into what is probably the most challenging part of this project: the formula that really makes it all work.

So far I have been user testing by changing the songs myself. After my observations on the way Pandora, LastFM, playlists and playlist generators usually work, as opposed to the podcasts that have workout music aimed at reaching a target heart rate or the music that is meant to make you sleepy.

My solution to this problem is a series of playlists, i’m still trying to determine how close together the intervals should be. So for instance I could have playlists set at 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 and so on. My software would go something like this:

void higher (){
Serial.println (“HIGHER is STARTING”);
// get BPM of current song, and chose a song from the next BPM level
}

void lower (){
Serial.println (“LOWER is STARTING”);
// get BPM of current song, and chose a song from the next lower BPM level
}

I’m calling this functions from a switch press in the device.

Other concerns are:

- how often is a change of heart rate relevant?

I’ve been using machines that have heart rate sensing integrated in them. They’ve been Polar brand mostly. This morning at Coles gym I used a bicycle for 40 minutes observing what they do with heart rate. The display alerted me of my current heart rate and also prompted me to hold the sensors for a new reading. They were well placed on two different parts of the handles so that you could chose the most comfortable ones. Then it constantly gave me readings, sometimes they changed in a 10 second interval which makes me wonder how often do they average them out? They have a list heart rate levels similar to this grafic to explain the relationship between age groups and heart rate that represents a cardio workout and an aerobic workout and then specified that it can vary quite a bit from one person to another. I noticed that the pedals changed their resistance to keep me at a certain heart rate once I had reached it. Finally I hit the cool down button and kept going at the same speed. My 5 minute cool down finished with me at the same speed as before it began. There was no promt to actually lower it.