Hi,
I have an Adafruit Flora 2 which has all input pins taken by:
I want to add a heart rate monitor to it. My questions are:
Thanks
With no free input pins you can do nothing.
You could add a port expander but given you are using a Flora then I suspect you are not very skilled in elections and would be unable to do this in a wearable way.
I suppose that this is a port expander. I'll probably need assistance from someone experienced to do that.
What about the heart rate monitor sensor, any suggestions/directions?
If you want to record an ECG or something, then you are going to need 2 input pins for this. Perhaps you can connect a heart rate monitor chest band to the bluetooth module to avoid this?
Well you could use an IR pulse rate meter if that will do you. Exactly what do you want to measure?
I want to find out the pulse from the wrist.
Actually after some reading I understand that wrist heart rate monitors based on IR sensors are not accurate enough, so I'll close the subject here.
george_i:
I want to find out the pulse from the wrist.
You want to find out what about the pulse?
george_i:
Actually after some reading I understand that wrist heart rate monitors based on IR sensors are not accurate enough,
Accurate about what?
Sorry if I was so "mysterious" 
I wanted to measure the heart rate with the help of a sensor.
From what I read, the accuracy of devices which measure the heart rate with a IR sensor is poor.
Accurate enough for what? Keeping a critically ill patient alive, or making a fun wearable costume? I don't think you need high accuracy for the latter!
Your weather sensor is not going to be accurate either. The barometric pressure may read accurately, but both temperature and humidity measurements will be affected by being close to a human body.
Paul
From what I read, the accuracy of devices which measure the heart rate with a IR sensor is poor.
I don't understand that because it is a digital signal so it would have to miss a whole pulse in order for it to be inaccurate or generate a new pulse from nowhere.
PaulRB:
Accurate enough for what? Keeping a critically ill patient alive, or making a fun wearable costume? I don't think you need high accuracy for the latter!Your weather sensor is not going to be accurate either. The barometric pressure may read accurately, but both temperature and humidity measurements will be affected by being close to a human body.
Paul
I'm trying to record environmental data (temperature, pressure and humidity) and correlate with physiological information during exercise.
The environmental data is relatively high accurate, as the sensor will have a decent space between the wrist and sensor.
Grumpy_Mike:
I don't understand that because it is a digital signal so it would have to miss a whole pulse in order for it to be inaccurate or generate a new pulse from nowhere.
The problem with the IR based heart rate sensors seem to be the fact that they are based on light, which require to place the sensor where the skin is more translucent, and even so is not enough, because of the skin pigments, which can obstruct the light.
Since the data is collected while the body is in motion could amplify this accuracy issue.
This is a review of wrist HRM sensors: CNET
The Sparkfun AD8232 sensor works great and gives a lot more information than heart rate. I used one to diagnose my own PVC (premature ventricular contraction). My PVC was later confirmed by a cardiologist reading data from a holter monitor. You can pick up extra sticky conductors on eBay.
Thanks Charlie.
Where did you placed the electrodes?
There exist Bluetooth heart rate monitor sensors. Polar for one makes such a device. This is a chest strap style sensor.
george_i:
Where did you placed the electrodes?
The recommended placement is two electrodes on the chest and one on the leg.