Dissecting a POTS-dependent smart home device

Products generally fail in the marketplace, I’ve noticed over the years, for one (or multiple) of a few reasons. Sometimes the fundamental idea is solid, but the implementation is poor. Sometimes both the idea and implementation are solid, but the bill-of-materials cost ends up being too high to turn an adequate profit at whatever price the market will bear (i.e., at whatever price the manufacturer ends up needing to sell the widget it at to convince consumers to pull out their wallets and buy the darn thing). Conversely, however, sometimes the fundamental idea is bad, and no amount of price-cutting will move product out of warehouses and off store shelves no matter how commendable the implementation is.

And sometimes, it’s none of these—idea, implementation, or profit margin. Instead, sometimes the product’s success is inherently dependent on the presence and longevity of a supportive ecosystem which ends up either not emerging or evaporating more quickly than forecasted. This latter scenario is, I wager, what doomed today’s teardown victim, Amazon’s Echo Connect:

As the caption above the “stock” image suggests, Echo Connect’s intent was to act as a “bridge” between a (separate) Amazon Echo smart speaker and a consumer’s plain old telephone service (POTS) or VoIP (in conjunction with a separate POTS “bridge”) connection, enabling the former to make and take phone calls using the latter, and as an adjunct to a conventional phone.

The implementation of the concept was admittedly imperfect (therefore my use of “adjunct” versus “alternative” in the previous paragraph), particularly regarding its lack of support for Caller ID and dual tone multi frequency (DTMF) (for navigating automated menu systems and the like), as this review video notes:

And some folks had setup struggles, judging from a subset of the published reviews. That said, they were only a subset, and a small one at that; more than half of reviewers gave it five stars (out of five), and less than 20% rated it less than three stars. Those are respectable stats, especially considering that generally, folks who have bad experiences are disproportionally motivated to post their perspectives.

So, why’s the device no longer available for sale from its manufacturer, Amazon, after being introduced in late 2017? Well, ask yourself: how many people (other than me, who gravitates toward living in high-elevation rural areas with unreliable cellular coverage and frequent premises power losses, therefore rationalizing paying for a POTS backup) do you know who even have landline phone service anymore? An ever-increasing preponderance of residences are cellular-only, maybe supplemented by broadband-serviced VoIP. Ironically, Echo Connect still requires a mobile phone for setup purposes. And Alexa devices already include support for cellular-based phone services, as this tutorial video from more than four years ago explains:

Echo Connect originally cost $34.99; I bought the refurbished unit I’ll be taking apart today from Amazon subsidiary Woot! in early December 2018 for $16.99. Yes, I finally pulled it off the teardown-candidate shelves, blew off the accumulated dust, and actualized my longstanding dissection aspiration. When I say it came in a plain brown cardboard box, I’m not kidding:

Top:

Front:

Left side:

Back:

Right side:

And bottom:

Open it up, and the Echo Connect is the first thing you see, swathed in retaining clear plastic:

Slip it out, and you’ll find another stratum of protective clear plastic underneath, surrounding it:

Underneath is a bubble-wrapped bundle:

containing all the “extras”: a slip of documentation, a USB power adapter, a USB to micro-USB adapter cable, an RJ11 cable, and a RJ11 splitter (presumably so you can continue using your conventional landline phone, too):

Here’s our victim, both before:

and after removal of the plastic strip protecting the top-side multi-LED display:

Here’s what the LEDs reference (left to right):

Power LED

Solid light: The device is getting power.

Wi-Fi LED

Solid light: Wi-Fi is connected.
Orange blinking light: The device is in setup mode.
No light: Echo Connect isn’t connected to Wi-Fi.

Internet LED

Solid light: The device is connected to the Internet.
No light: The device isn’t connected to the Internet.

Phone LED

Solid light: The phone line is connected.
Slowly blinking light: Echo Connect is on a call.
No light: Your phone service was not detected.
Rapidly blinking light: The line registration failed.

As usual, the device is accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes. Echo Connect has dimensions of 5.1” x 3.5” x 1.2” (130 mm x 90 mm x 29.5 mm) and weighs 4.5 oz. (126.9 grams). Here are some more perspectives, of the comparatively bland front and sides:

The rear is a bit more interesting:

Note the lack of a RJ45 wired Ethernet connectivity option, which some reviewers “dinged” the device for. This stock photo describes what is included:

And last, but not least, the bottom:

I’m betting that underneath those four rubber feet is our pathway inside. What do you think?

Yep!

In earlier side-view photos you might have noticed the “lip” circumnavigating the device at both the top and bottom. The bottom indent is actually purely cosmetic, molded into the plastic. The top indent, conversely, is functional from an entry-path standpoint:

First things first, let’s take a closer look at the antenna, which ended up being one of the more bewildering-to-me aspects of the design:

The specs indicate that Echo Connect supports both 2.4 GHz and 5 GHz Wi-Fi, and FCC documentation (ID 2ANCL-2539) confirms that it also supports Bluetooth (presumably for initial mobile device-pairing and Echo Connect setup and activation purposes). Why, then, can I only find one antenna (albeit seemingly consisting of two separate embedded antennae structures), and more precisely, only one mated wire from it to the PCB? Every other dual-band Wi-Fi device I can recollect having disassembled to date has either two distinct antennae, one for each band, or a unified dual-antenna structure with two wires coming out of it. Sometimes, the 2.4 GHz antenna does double-duty for both Wi-Fi and Bluetooth, but that doesn’t explain the seeming 5 GHz absence. And sometimes one or multiple antennae are embedded in the main system PCB, too (or other times, instead), but I don’t see any of these, either…ideas, readers?

Onward. In that earlier initial photo of the PCB, did you notice the one screw toward the top, holding it in place in the lower half of the chassis? I didn’t, at least at first. PCB extraction works much better after it’s removed, don’cha know…

That’s better:

Let’s look at the underside first:

Not much of note here, aside from a cluster of passives in one corner, located where the RJ11 jack is on the other side of the PCB:

and another toward the middle which, from past experience, I’m guessing is associated with a processor on the other side of the PCB:

Most of the “action”, unsurprisingly, is on that aforementioned “other side of the PCB”:

Note first off, the four LEDs along the bottom edge, corresponding to the top panel indicators mentioned earlier, and one of which is paired with a photodiode for (presumably) ambient light sensing purposes. But I’m betting that most readers’ eyes were instead immediately drawn to the Faraday Cage at lower right. To wit, you know what comes next, right?

That previously mentioned second cluster of passives indeed corresponds to the main system SoC, a DSP Group DVF9918 unified communications processor in the middle of the photo, with a 2007 (!!) copyright stamp up top. To its right is a Zentel A3V56S40GTP-60 256 Mbit 166 MHz SDR SDRAM dating from a decade ago; wow, I haven’t seen one of those in a long while! Between and above them is a Macronix MX25L25635FM 256 Mbit serial NOR flash memory. In the upper left corner is an unknown IC stamped as follows:

3050FM
EMS14J
1732

And below it and toward the bottom left corner of this particular photo is a 25 MHz crystal.

In the earlier overview shot, you might have also noticed a “shiny” IC in the lower left corner, not Faraday Cage-covered. It’s the AMPEK Technology AP6255, a module that implements 802.11ac Wi-Fi and Bluetooth 4.1 functionality (therefore rationalizing the antenna connector right next to it).

And there are additional clusters of passives-and-such in the upper left quadrant, nearby the RJ11 connector and reset switch:

as well as in the upper right quadrant, geographically (and, I’m guessing, also functionally) related to the power input. To wit, the one with a squiggly mark seemingly hand-added on top (for unknown reasons) is a Texas Instruments TPS54231 step-down DC-DC converter.

Some PCB side views to close, starting from the front and sequentially rotating around:

And with that, I’ll step away from the keyboard and await your thoughts in the comments!

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

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