New Apple watch

Hi All,

I want to buy my son an Apple watch so he can see his bg reading from his Dexcom G5 without having to take out his phone. I understand that there is new technology awaiting FDA approval that will allow bg readings to be displayed directly from the G5 to the watch, but this is not available yet.

My question is : does it matter which Apple watch I buy? I know the 3 is more expensive, but are there any benefits to this upgrade, and will the new technology, once approved be able to work with all models or just the 3?


We use an Apple watch version 2, and it works just fine. It is not clear to me if it will be able to connect directly to the Dexcom, (it probably won’t), but in any case, the direct connection is still awaiting software upgrades from Dexcom.

Also, once someone connects directly to the apple watch, it is not clear if share would still work. For us right now, my son shares with both his mom and myself, which is quite helpful. Although, there are times it would be great to not have to bring the phone, like when he runs cross country.

What is the usage you are interested in?


I am still using a series 1 watch. If you don’t need the cellular connection for calls on the watch for another ~$15/no, get the series 1 and save the extra bucks. They will all link directly to the Dexcom once Dexcom released the updated phone app with the feature enabled.

I’ve played with it a bit already on my s1 and the watch detects the Dexcom transmitter - it just won’t make the connection without the Dexcom update.

Sharing would either require the s3 or the phone nearby, if Dexcom adds it to the watch app. But I wouldn’t hold my breath for that.


@mlg, I believe that the new tech can only work on the 3.

The other aspect I would look at is upgrades: the older Apple watches likely will not get upgrades for as long as the 3: Apple obsoletes devices after a while, and they don’t get OS upgrades or patches any more.

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@Chris my son is 17 and I thought it would be good for him to have the watch so he can see his readings without taking out his phone, especially when he is in class. Also when he is at baseball practice and in the weight room, I can envision the software upgrade really helping him because he does not always have his phone close to him in those situations. I do use the Share feature and probably would want to continue using that until he goes to college.

It sounds like from all the comments, I would be better off with the 3?

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Yes, it does sound like the 3 is your best bet. Then most likely when he is going watch only, you won’t get the share. What is not clear yet, is what it takes to switch between the watch and the phone. Hopefully that is easy, otherwise the Share will be “interesting”. I just love new tech.


@Chris But that is with the future software update correct? If I get him the watch now, will the share feature still work for me?

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Yes, it requires a future software upgrade from Dexcom, and today he will have to have his phone near the watch to see it.

But of course, because the path is Dexcom Transmitter - Iphone - Apple Watch (1,2 or 3), you will still get the share information.

My son really loves the watch in school, because he can check his bg anytime without the teachers getting bent out of shape about his phone use.


@Chris Exactly! I am always afraid he will be low during a test and be afraid to take his phone out because the teacher will think he is cheating, so I think this will be great. Can’t wait for the direct connection to watch. That will be so helpful during practices. Thanks for the input!



I guess it’s a knee jerk reaction from the teachers but I wish they’d be sensitive to people’s medical needs.


Oh, they get plenty sensitive when we trot out his 529 and remind them of his rights, but honestly, I wish it didn’t come to that.

One teacher this year even took roll call from the phones being put into numbered boxes, and since my son didn’t put his phone there, was marked absent, even though he took the final…


That is not correct. Literally, the only difference between the 3 watches is faster processors the cellular on the series 3, and slight case adjustments to for the new processors, battery, and cellular.

Direct connect will work on any of the 3. It only uses Bluetooth and the Dexcom update.

I’ve already connected the transmitter to my series 1 - just the is then no data as the Dexcom app doesn’t have the data link between the watch and app.

If Dexcom does allow Share, it is most likely it will have to be set up on the phone, and then data will use the series 3 cellular.

@mlg - keep in mind that not only will a series 3 cost several hundred $ more, but you will have the cellular service to pay - with taxes, roughly double what your mobile provider quotes you. How often do you really expect him to be without his phone?


@kmichel Probably mostly for baseball practices and in the gym, which is most days for 2-4 hours. Last week, he went to a prospect camp at a college. His phone was in his bag on the other side of the stadium. This was a full length indoor football field and he was pitching on the opposite side. Of course, he was low. He would have known sooner if he had this technology. I think it would be really helpful for him.


No, No, No…this type of behavior by a teachers/ school administrators is unacceptable and discriminatory. :face_with_symbols_over_mouth:

@Chris I’m sure you handled this deftly. I would have been in the Principle’s office in a heartbeat but I doubt I would have been able to keep a level head.


Agree completely with you, but deft isn’t my middle name, however, I have learned how to keep my cool since we have about 2-3 instances a year that require intervention.


I get so angry just reading what you are going through: I guess I can really see myself in your shoes…

So far things have been great at school, but this is only middle school. I figure HS is going to be a different ballgame.

@kmichel, are you sure? I was under the impression that the now famous Apple Dexcom demo would only work in the 3?

Really glad everything has been great, in the grand scheme of things we are lucky, i.e. we have never had to go past the assistant principal to get satisfaction, but it does remain frustrating at times.

Thanks for the support.

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Well, @Michel … it isn’t a simple answer to give. A lot depends on how Dexcom implements it. It is technically possible to connect the transmitter to any Apple Watch running Watch OS4. Watch OS4 adds the Core Bluetooth API that Dexcom will use. Per my sources at Apple, they are asking Dexcom to display on any watch running Watch OS4.

It is technically possible to send the data from the sensor directly to any Apple Watch. I have established a connection between my S1 watch and the G5 sensor. However, without the app updates, there is currently no way to display the data (Yeah, my team does BT for a living).

The thing gained on Series 3 watches is the ability to upload data to the cloud (Clarity) directly and to Share without the phone nearby.

For S1 and S2, the watch would need to sync the data to the phone when it came back in range in order to get it into Clarity, and you would lose real-time sharing. Keep in mind the transmitter itself can store a certain amount of data when not connected to the phone, which is how they fill gaps on short disconnects. The Watch has enough memory to store another chunk of data. I haven’t worked out the exact amount of time one could go without the phone.

All that said, Kevin Sayer (Dexcom CEO) claims the G5 can connect to 2 Bluetooth devices at the same time. However, their current implementation only allows 1 device and the receiver. Dexcom’s tech guys claim the receiver channel is not Bluetooth, but I haven’t torn apart a receiver to verify one way or the other. If there are 2 Bluetooth channels, they could easily connect to both a watch and phone/pump/“other device”.

I have to believe they have 2 available channels since Kevin Sayer says setting changes and calibrations would still require a phone. Even with the S3 watch, the phone still needs to be connected.

But then Dexcom does not have a good track record for implementing things that make sense, even when technically feasible. Think of that awful update when they bypassed the vibrate switch on the iPhone. You would be surprised at some of the “possible fixes” their lead firmware engineer considered, before ignoring it all together.

We will have to wait and see.


A new version of the Dexcom iOS app arrived today. It has the ability to mute sounds with the ringer switch (except for urgent low alarms and a couple other ones).

Sadly, I don’t see any evidence of this version being able to connect directly to the Apple Watch.