Originally Posted by jawz101
if a device has the Bluetooth logo, it meets Bluetooth protocol certifications and should work
Actually, Yes, they work -BUT- Android does not work with them.
Most phones do support BLE in their hardware, but android does NOT have the API-calls to access the hardware (until 4.3).
If you have a Bluetooth Smart device ( like your heart rate monitor ) and you try to pair it with any BLE capable device, it will work to a certain point, since it is Bluetooth after all. But bluetooth smart is a "simplified" version of bluetooth, with the intention to cut power usage so you can run on a coin cell battery for months, even years in some cases. The problem is that while they did cut the protocol down they also broke backward compatibility to a certain degree.
So communication from your Bluetooth smart device to your mobile phones bluetooth chip does work, but since "things" have changed, the part behind the bluetooth chip on your phone has to cope with the new differences. That does not happen in android before 4.3 . Some manufacturers like Samsung and HTC and Motorola (SHM) have done their own work (all three different approaches) to cope with the problem.
Me, as an APP developer, could go to all SHM companies and make my app work with their "workarounds" just to support a handfull of phones, coping with the quirks of those workarounds. -OR- I simply wait for google to implement BLE stack on Android in a newer version.
The reason it took Google till Android 4.3 to get BLE working was that google already did want to cleanup the Bluetooth code and waited till all is finished ( that's what I've read online ). I think that was the wrong approach. Since most Handset manufacturers do not update ROMs as fast, the Market share of android devices that truly work flawless with BLE will continue to be low for the next 2-3 years.
I am doing a masters thesis on bluetooth low energy and want to use it with android, although it should be clear that I need a Phone, I am still hessitating to buy a Nexus 4, although I am in need of a BLE compatible Phone.
On the other hand there are reports that the previous nexus phone, the galaxy nexus, has a BLE capable chip and meanwhile did get Android 4.3, but in that case (seemingly) the drivers for the BT-chip do not work with bluetooth smart / BLE. (A good reason to get angry)
To get back to your Heart Rate Monitor (HRM) straps,
most probably the old ones did do some "own development" with older Bluetooth. The point is that BLE has a specific profile for HRM devices, so they will all be mix-n-match / compatible-to-eachother once the market for compatible apps, compatible phones and compatible straps is existent. Earlier HRM straps did implement their own data transmission protocol over the well known bluetooth serial protocol. That is the reason they are compatible with only one or two apps (or one app with a couple of straps).