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Comment by prennert | Hacker News Reader

It is surprisingly difficult to make synchronisation work between two devices that might run different hard- and firmware and even potentially software versions. Cloud based APIs as middleware is soo much easier in comparison.

I am completely with you conceptually, but from experience I can tell you that even if there is a commercial incentive to allow for local communication it takes a few days to get it working with the cloud and months to do it locally only. And you really need to know what you are doing to make it safe and reliable in all eventualities.

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>It is surprisingly difficult to make synchronisation work between two devices

No it isn't. We were doing it for years before "the cloud" or even the modern Internet even existed using Bluetooth, RF, IR, and cables. Have you ever looked at a .fit file on a Garmin watch? It's a binary format, but is straightforward to convert to CSV, and doesn't contain much beyond timestamp, latitude, longitude, altitude, heart rate, cadence, and a few other fields. Calculating distance, duration, training effect, calories burned, etc. is simple summarization and arithmetic, plotting course on a map just requires an offline map and a plotting library. It already does all of this ON THE WATCH itself without needing any connection to anything else, so there's nothing stopping an app from doing the same thing locally on a much more powerful iPhone or Android phone. The Garmin cloud is only inserted in the process here so they can monetize your data.

And even many Garmin devices sync via the phone and app: My Edge bike computer connects via Bluetooth to the Garmin app, which uploads the file to the connect website and then downloads the analysis again. There is no technical hindrance for doing analysis in the app (I wrote my own decoders for the fit file format some time ago for building my own archive) except that this makes it simple to have consistent state and defined usage of things like altitude correction.

Except battery life. Nobody wants an apps that are battery hogs. Sending the data is less computationally expensive and therefore uses less energy. Also, takes out the difficulty figuring out how this processing might impact Various phone models, one word they didn’t care or were lazy both are bad pr.

Not true. It is much, much more energy intensive to run an RF link up to a tower or WiFi than to sum 2000 rows of 10 column wide data. RF works by emitting energy into free space, and there is absolutely no way it is cheaper for this type of thing (especially if it takes the transmitter out of sleep mode, like if you’re really out there and in airplane mode).

I can tell you that I would welcome the option to sync locally the last few days, even if I had to plug in my phone to support the massive power costs. Maybe they could offload the processing to the watch (since it already is able to display a summary of these files).

I used to sync my old 910 via ANT+ to my former Samsung Galaxy which has ANT+.

Using a third party transfer app. and then viewing it with another third party app, directly on my phone. no battery complaints, but those ANT transfers were pretty flakey.

I dont think you can browse files on the watch through bluetooth, but an OTG cable would do the trick.

I imagine it's more difficult to make it so every one of your different devices (Garmin has an extensive lineup) is able to interface appropriately with every other device than it is to code against a straightforward HTTP(S) server sitting somewhere in the cloud under your complete control. Fits Hanlon's Razor better, too.

> It is surprisingly difficult to make synchronisation work between two devices that might run different hard- and firmware and even potentially software versions. Cloud based APIs as middleware is soo much easier in comparison.

Even if that were true (and it's not), it's not how Garmin sync works. The website isn't cloud based middleware, and the watch and phone sync over bluetooth. It really is as dumb and frustrating as the OP describes.

Before syncing with the watch, over bluetooth, the app connects to the Garmin website. If the web connection fails then the transfer fails.

And yet my Timex Datalink did it flawlessly in 1994, using nothing more than the predictable flicker of a CRT raster.

> make it safe and reliable in all eventualities

You mean precisely like it isn't now?

I'd much rather have something fail locally based on conditions that I can affect, than fail remotely and be completely out of my control.

And yet everything from Palm Pilots to iPaqs were able to do it a quarter of a century ago with just a beam of light.

My understanding[1] was that these types of devices sync by sending a blob over bluetooth to the paired cell phone, and then the cell phone uploads this to the cloud to be decrypted. What kinds of devices are you talking about?

[1]: https://hackaday.com/2017/12/29/34c3-fitbit-sniffing-and-fir...

FIT files aren't encrypted. You can copy them directly to your computer are parse them easily.

Last time I checked they hid the format description behind an NDA ... aside from that no issue indeed.

I never understood how that works. All it takes is one person to post it publicly and then everyone has it.

Maybe they are rot13 encrypted.

Quadruple rot13 for enhanced security.

It works by having lawyers :)

And we'll, there seem to be ready to use libraries, you can use without signing the NDA: https://github.com/search?q=fit+garmin&type=

What makes it so difficult? What are some concrete problems you encountered?

It is not intrinsically difficult, it's made difficult by the fact that the companies themselves specifically want to have their infrastructure in the mix to have access to valuable user data. There's no particularly difficult challenge to sync the phone and watch directly, offline. A good chunk of revenue comes from services which rely on the data being in the cloud.

I agree that gathering user data might be a significant factor why even products of large companies do not support cloudless communication and sync.

I just wanted to point out that since cloud based communication is so easy nowadays, doing sync without cloud support is a significantly larger effort. Not unachievable though.

I worked on a competitor.

It was 100% about user expectations, the data was never mined for anything.

People use multiple phones, replace their phone, delete apps to free up space, and still expect their data to be there.

Running a cloud infrastructure for PII isn't exactly low cost, and bundling a life time subscription with a one time device purchase is horrible economics. It isn't done for no reason.

> the data was never mined for anything

Oh I wasn't implying what's generally seen as "data mining". But for such a company to offer many of the features in the paid services they need that data. They don't have to sell it to others, they only have to sell it back to the users as added services even included in the price of the hardware itself. Those added services can be as simple as sync between multiple phones or sharing on social media, or premium features like advanced analytics.

On the other hand this kind of data can be also sold entirely anonymized. Strava does this and many cities' urban planners buy the data to understand better how the city infrastructure is used by the people (running, cycling, etc.) and how to develop it.

I'm not saying there's no value in it, just that without it the value of the product decreases significantly. So it's in the manufacturer's best interest to have it as part of the basis of their offering.

Releasing the clutches of control over user data/devices is a very difficult concept to grasp for particular type of business people.

You need to open a connection, which requires user action. When both devices are already connected to the cloud, the synchronisation can be done "transparently", which is what users today have come to expect.

Another reason is that if you still want to sync with the cloud, you need two synchronisation systems that have to be kept in sync too.

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