I have D2 Air but haven’t used GA-related functions much. METAR is displayed but is bound to phone+data connection. It logs the flight. There are many other functions, but all that are also offered by any moving map. SPO2 measurement works but regular readings drains the battery faster. Compared to Apple watch the battery life is better.
AFAIK all smart watches are tied to your phone for any “data” functionality. They don’t have a SIM card… some have wifi but that uses quite a lot of power so forget the “56 day battery life” claims, and anyway the UI is so horrible that you will set it up only for your home wifi.
AFAIK all smart watches are tied to your phone for any “data” functionality. They don’t have a SIM card…
Not entirely true, yes no physical SIM card, but the eSIM in my Apple Watch does cost me five quid a month and does well with cellular connectivity.
Peter wrote:
AFAIK all smart watches are tied to your phone for any “data” functionality. They don’t have a SIM card… some have wifi but that uses quite a lot of power so forget the “56 day battery life” claims, and anyway the UI is so horrible that you will set it up only for your home wifi.
Samsung offers an “LTE” variant of the Galaxy Watch 4 and 5 which has a SIM Card.
As you say, using that will drain the battery even faster.
Does anyone know how the ECG feature of smartwatches can possibly work?
You need two connections to pick up a signal. But in this case you have just one. One watch needed you to touch the top of the watch with your other hand, and then the method is obvious: you can easily pick up a signal (from the depolarisation of the heart muscle) from two hands.
Peter wrote:
Does anyone know how the ECG feature of smartwatches can possibly work?
I can only speak for my cheap chinese L7.
If ECG means pulse, yes, it works just fine. The graph it shows is garbage but the pulse frequency is accurate.
BP is total garbage.
Oxygen saturation works within about 0.5% in comparison with a medical finger oxymeter.
Steps work fine, the counters of the Samsung phone and the watch (not connected!) are pretty close.
ECG is not pulse; it is an electrical signal.
It’s actually possible that all the “ECG” marketing is a big con and it just picks up the blood pressure pulse and presents it as an ECG waveform.
Whereas e.g. this is clearly picking up the electrical signal.
Peter wrote:
ECG is not pulse; it is an electrical signal.It’s actually possible that all the “ECG” marketing is a big con and it just picks up the blood pressure pulse and presents it as an ECG waveform.
Whereas e.g. this is clearly picking up the electrical signal.
Had a chat with a guy that was researching thoroughly – apparently, to do a proper ECG you need multiple contact wires attached and you cannot do that with a smart watch. I think he was saying something in lines of “some smart watch can catch a very few severe problems, but doesn’t come close to the usual GP’s ECG machine”.
It think about it as a selling point, no more.
You need two connections to measure voltage. No way around that.
The “obvious” minimal system is measuring between two hands. With the heart between them, you will get a nice signal. That is what the device I linked above does.
There is no way one could measure the ECG voltage across the tiny patch of skin under the watch. The only way which might possibly work is by using the capacitance between the watch and “the rest of the universe” as the ground return, and I think that will not be possible by several orders of magnitude, at the super-low frequency involved.
I heard of a watch which did ECG if you touched the top of it with your other hand. That is then very possible.
IOW, I have a feeling that the watches which have an “ECG” function, which does not require a second connection, are a con.
For the Apple Watch:
“It does so by using both the electrical heart rate monitor on the underside of the Apple Watch and the Digital Crown, where users need to place a finger from the opposite hand.”
Can’t vouch for the accuracy of the article, but sounds plausible.
