Teardown: Tile Mate Bluetooth tracker relies on software

I periodically go through bouts of misplacing my keys. And my wallet. Sometimes at the same time. To address the issue with the disappearing keys, last October (during an Amazon Prime Day promotion) I bought a Tile Mate two-pack (one for my keys, and one for this teardown) for $33.59 versus the normal $47.99.

photo of the Tile mate bluetooth tracker

Source: Tile

Two weeks later, I followed that up with an also-on-sale Starter Pack (also known as the Starter Bundle) of another Tile Mate (for my wife) and a Tile Slim (for my wallet) on sale for $34.99, versus the normal $49.99.

photo of the Tile slim bluetooth tracker

Source: Tile

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I’m not quoting these prices just to show you what a bargain shopper I am; I’m striving to point out that even at the normal prices, these aren’t expensive items. Subtract out the Amazon or other retailer markup (thereby explaining why Tile also sells its products direct on its own website), along with inevitable development, support, returns, inventory, manufacturing, and other costs, and if Tile wants to still turn tangible revenue (and profit!), it needs to do two important things:

  • sell a lot of them, and
  • keep the bill-of-materials cost at a minimum.

Unsurprisingly, therefore (as you’ll soon see), there isn’t much to a Tile device, at least from a hardware standpoint. The bulk of the implementation uniqueness is instead in software, and much of that runs not on the Tile device itself but on the connected mobile device (smartphone or tablet) and from there as a service on the cloud server.

But let’s step back for a minute before we get too far ahead of ourselves. What is a Tile, and how does it work? Some of you might already know, and others of you may have already figured out the answer from my earlier-described usage scenarios. It’s a tracker, attached to or otherwise associated with something else (as you can probably tell from the Slim image, for example, it’s credit-card sized for ease of wallet insertion) and a means by which you can find that “something else” when it’s misplaced.

Often, this class of products is referred to as Bluetooth trackers, and while that qualifier (more specifically Bluetooth Low Energy, i.e., BLE) is accurate in this particular case, it’s increasingly limiting. Samsung’s newly-announced Galaxy SmartTag+ trackers, for example (along with Apple’s long-rumored and recently-introduced AirTags), support both BLE and ultra-wideband (UWB), the latter enabling more precise locating (assuming the connected device also supports UWB, for example). That said, this is a perfect application for BLE versus more power-hungry conventional Bluetooth; the required data payload is scant (conceptually a slightly more elaborate version of a periodic “ping”) but long battery life is critically important.

To wit, when the connected smartphone or tablet and tracker are in range of each other (up to 200 feet in the case of the Tile Mate, for example), the former logs the approximate location of the latter by proxy, leveraging the location-identifying resources and services already built into the mobile device versus requiring power-hungry GPS in the tracker. Can’t find your keys? Fire up the mobile device app and you can send a signal to the tracker, causing it to audibly respond. And the process also works in reverse; if you can’t find your smartphone or tablet, press a button on the tracker and it’ll provoke a ring tone from the mobile device, if they’re in range of each other at the time, of course. The concept works well, but can cause awkward situations if, for example, your keys (or a wayward finger) unintentionally bump the tracker button while the assemblage is in your pocket.

If the tracker’s out of range, the mobile device app can show you the tracker’s last known location (upgrade to the paid Premium service tier and, among other things, you get alerts whenever the tracker’s out of range, as well as a 30-day location tracking history, examples of software-enabled incremental and ongoing service revenue leveraging the same foundation hardware). And if it’s truly lost, you can activate “Notify When Found” in the app. At that point, every mobile device in the Tile network joins the hunt, alerting you (anonymously) whenever any device detects the tracker’s proximity presence. This all assumes the tracker’s battery’s not dead, of course. And it’s an example of the “first mover” advantage; while other companies’ trackers also offer similar capabilities, their customer base (therefore network) is much sparser (per the most-recent edition of The Wirecutter’s review-and-recommendations writeup, Tile has sold 26 million trackers to date, representing approximately 90% of the market).

Enough of the setup, on to the dissection! As usual, I’ll begin with some packaging shots, complete with clever marketing phrases. Since, as I already mentioned, one of the Tile Mates in the two-pack is already in service, the box is already open and one of the “storage bays” inside is already empty:

photo of the front of the Tile mate package

photo of the back of the Tile mate package

photo of the Tile mate directions

photo of the Tile mate in its box

The only other thing inside the box is a scant slip of documentation:

photo of the Tile mate paper documentation

The Tile Mate being analyzed today has dimensions of 35×35×6.2mm and weighs 6 grams; alongside it is an as-usual United States penny (0.75 inches/19.05 mm in diameter) for size-comparison purposes. The Mate’s big brother, the not-shown Tile Pro, has twice the claimed range and a louder ring, but is also notably heftier, at 42×42×6.5mm and 12 grams. In the center is the aforementioned activation button for locating a BLE-tethered smartphone or tablet, along with a hole for attaching to a key ring:

photo of the front of the Tile mate with a penny for scale

On the back you’ll see the replaceable battery compartment “door” along with a three-hole aperture for the speaker. The QR code is, I presume, used for individual device ID logging purposes during the manufacturing process.

photo of the back of the Tile mate with a penny for scale

More on that battery compartment: prior-generation designs had included an embedded (non-user-replaceable) CR2032 lithium coin cell that was soldered to the system-sourced power contacts. Obsolescence by design, indeed! In fairness to Tile, after the battery died you could ship it back for discounted-device replacement under the ReTile program. And now that the company is shipping successor devices that use owner-replaceable CR1632 coin cells (in most cases, the Tile Slim battery is still embedded, although the company estimates a 3-year operating life), if you send in a dead first-gen device, you’ll get a next-gen replacement.

photo of the back of the Tile mate with the door and battery removed

That removable battery compartment “door” (reinforced with a rubberized moisture barrier on its underside) is, along with the speaker holes, a big part of the reason why Tile calls the Mate water resistant, not waterproof.

photo of the back of the Tile mate showing the back of the battery and water resistant battery door

The two halves of the chassis are otherwise held together with sturdy adhesive, which gave me a bit of a struggle but ultimately yielded to the pressure of my thin flat head screwdriver:

photo of prying open the Tile mate with a screwdriver

Immediately visible is the PCB-mounted switch corresponding to the topside activation button:

photo of two halves of the Tile mate showing the PCB

The PCB lifts right off the half-chassis; it’s not held in place with any sort of glue-or-clips-or-screws-or-other retention. Note that the piezoelectric transducer (i.e., “speaker”) is more firmly attached to the half-chassis, however:

photo of the Tile mate speaker and PCB

Let’s take a closer look at that initial side of the PCB:

photo of the Tile mate PCB back

There’s not much to see save for the earlier-mentioned switch and a bunch of test points. The other side, however, is more interesting:

photo of the Tile mate PCB components

The larger of the two ICs is a Nordic Semiconductor nRF52810 Bluetooth 5.2/BLE control SoC, based on an Arm Cortex-M4. Interestingly, at least to me, Tile had previously used the Arm Cortex-M0-based DA14580 from Dialog Semiconductor. Nordic was so pleased about its partner’s supply switch that it even issued a press release.

The function of the other, smaller IC marked P8904, DDA9 initially baffled me, and to this day I can’t find reference to this particular chip (or its supplier, for that matter). But I happened to be perusing the FCC certification documentation for the Tile Mate (2ABXLT9001, if you can’t discern the under-battery-door-marked ID in one of the earlier images) and noticed a different IC in that same PCB location, marked:

6240
GC2
839

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It’s the MAS6240, a piezo driver sold by Micro Analog Systems Oy. Alongside it is one of the two electrical contacts that press-connect to the piezoelectric transducer; the other one is next to one corner of the Nordic Semiconductor chips. And speaking of Bluetooth, the PCB-embedded antenna is prominently visible along one edge of the PCB.

That’s pretty much it, unless you’re into passive components, of course. As I foreshadowed upfront in this writeup, there isn’t much to the device, at least from a hardware standpoint (clearly, software and services are a different story!). And with that, I’ll step away from the keyboard; I look forward to your thoughts in the comments!

Brian Dipert is Editor-in-Chief of the Embedded Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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