Sunfounder PulseSensor Heart Rate Monitoring Module

To be clear - I give this product 4 stars because of a "you get what you pay for" type analysis. The signal itself is not that great, but it can work, and this is a sensor that is a third the price of the real deal. I made a comparison of all three heart sensors on the right with an oscilloscope, buying 2 of each in order to account for error. This product is actually not that bad if all you need is a heart beat - the signal is very small but it is consistent. You won't get a lot of good information needed for HRV out of this - literally you will just get a little bump every time the heart beats. However if all you need is BPM or just the connection to the heart itself, this sensor is a fraction of the price of the truly amazing original Pulse Sensor. One thing you might be missing is the information that you need to protect the circuitry on the back of the module before you use it - a few drops of hot glue will do the trick.