TP-Link’s Tapo P110M smart plug: Matter and energy monitoring matter

A seemingly newer device reverts to a legacy processor architecture, in comparison to one certified earlier that same year. Does it matter? And was it due to Matter?

This is the end
Beautiful friend
This is the end
My only friend, the end
The Doors, “The End”

In quoting those epic song lyric opening lines, I’m not referencing an ex-girlfriend, as Jim Morrison had reportedly done, but instead applying them to my long-running TP-Link smart plug teardown series. This entry, for the Tapo P110M, marks the end of the publication line (at least as currently planned) for this specific content cadence.

I hope you enjoyed reading about the various devices as much as I enjoyed taking them apart, photographing them, and writing about them.

The series, up to this point, began in February and encompasses the following analyses:

Reiterating a frequently uttered mission-statement mantra I most recently chanted last month, my basic aspiration with this project was to ascertain to what degree (if any) differences in the company’s various smart plug products’ feature sets, broadly between the Kasa and Tapo product lines as well as between products within a given line, were due to hardware variability versus (or in addition to) software-implemented inconsistency. Last month’s unveil was a particular hardware-evolution doozy, as it involved the processor architecture (and associated codebase) conversion from Arm (Realtek) to RISC-V (Espressif Systems).

So, what will we find inside the Tapo P110M? Usually, but not always, TP-Link’s Matter smart home and IoT protocol-supportive product variants include “M” as a product name suffix. More generally, in addition to Matter cognizance (or lack thereof), we’ve seen over this past year that the manufacturer also differentiates devices based on parameters such as energy monitoring and reporting capabilities and Apple HomeKit protocol support, not to mention cosmetic variances such as size, shape and weight, switch and activity LED locations, and the like.

The P110M, for example, implements all three aforementioned software enhancements, only one of which (energy tracking) last month’s Tapo P115 shares. Let’s see how, if at all, this differentiation is also reflected in hardware.

Feature set confusion

Here’s a stock shot of the Tapo P110M, to start.

 

Looks curiously familiar, albeit not identical, doesn’t it?

My two-pack came from Amazon’s Resale (formerly Warehouse) website area and set me back $13.77 after a 30%-off promotion active at the time, plus tax. While just now revisiting the product page both there and at TP-Link’s website, I was initially confused, since the latter (not to mention TP-Link’s broader product line overview page) explicitly notates support for Apple’s Home protocol, Siri interface and the like, all absent from the former. However, I suspect Matter cognizance is at the nexus of the discrepancy, as noted at Amazon product page verbiage:

Matter-certified devices, regardless of brand, can work together and are compatible with most major smart home platforms like Amazon Alexa, Apple HomeKit, Google Home, and Samsung SmartThings. Enjoy more flexible and unified control.

Translation, I’m guessing: the Tapo P110M doesn’t support Apple services directly, but instead implicitly via their common Matter-support intermediary.

Here’s the usual suite of outer box shots, complete with the also-as-usual 0.75″ (19.1 mm) diameter U.S. penny accompaniment for size comparison purposes. Top.

Front.

Left side.

Back.

Right side.

And bottom.

Peeling away an edge of the information-obscuring Amazon Resale sticker exposes to view the hardware revision number—v1.6—of what’s inside. And in a rarity, at least from my experience, that’s the only hardware version option listed on the product support page (albeit with multiple to-date associated firmware updates). A refreshing change of pace.

Sticker shock

Let’s now see what’s inside.

One of the two Matter stickers was previously removed from its original backing sheet. Wonder where it went? Hold that thought.

I’ve usually found with returned-and-resold stuff like this that only one of the multiple items in the package has been removed prior to re-placement and shipment back to Amazon. I generally select that same one as my teardown “victim”. But which one was it in this case?

Again, it’s usually the one on the left (or upper left corner for a quad-device box). But the prior owner of this set might have been left-handed; the indent for the device on the right is frayed.

Here’s more visual evidence of the prior owner’s out-of-box device selection preference. There’s the missing sticker, now adhering to the top of the smart plug on the right.

Putting the left-side device aside, let’s continue with the usual overview photo set. Top, again.

Front.

Left side.

Back.

Right….what?

Turns out the Matter QR code and info are already stamped on the device’s right side. Turns out, too, the owner stuck the supplemental sticker on the wrong device, because the info sets don’t match. Truthfully, I don’t think the sticker’s intended for the device at all (unnecessary info redundancy, don’cha know) but if so, it instead should have been stuck on top of the other device.

Maybe owner confusion is at the core of why it ended up getting returned? Dunno. Onward.

As usual, the bottom of the device contains useful info, including the FCC ID (2BCGWBP1100).

Quick aside: the FCC ID for last month’s Tapo P115 is quite similar (2BCGWP110). That’s not confusing at all, right? Its listed “final action date” is February 29, 2024 (a leap year, obviously) while this one’s “final action date” is July 24 of that same year. Therefore the “seemingly newer device…in comparison to one certified earlier that same year” prose in the subhead.

A screw loose

One more stock shot to go: the latest in a line of company-supplied interior concept images:

And that’s enough for the setup; let’s get inside. Practice makes it perfect, apparently; this time not only was no bloodshed, but no tabs were snapped, either.

Voila.

Here’s the half you’re undoubtedly all most interested in.

Device-to-device design consistency takes the form, among other things, of the relay, yet another Churod A16-V-105DA2F.

The bottom and right-side views are equally reminiscent and unmemorable.

And, last but not least, what of the digital PCB on the left? I’ll start with the boring side (unless you’re into traces, test points, and/or embedded antenna silhouettes, that is).

That’s what’s known as a tease. Here’s the side you care about, especially after last month’s reveal that it had captured and encompassed a processor architecture shift.

No such momentous luck this time, alas. We’re back to Realtek’s RTL8720CM at left, previously found on several previous TP-Link smart plug designs, along with a Shanghai Belling BL0937 single-phase energy monitoring IC and Eon Silicon’s EN25Q32B 32 Mbit serial flash memory on the right (not found with the Tapo P115, since the NVM was single-package integrated alongside the processor in that case).

And of course there’s also yet another mysterious five-lead packaged device (I’m still sticking with my guess that these are dual transistor devices), this time marked “TACeE1” in the lower left corner. Plus, we can’t forget the switch alongside an LED smack dab in the center.

Why the seeming chronological advancement but architectural back-step from RISC-V is back to Arm this time? My guess is that it has everything to do with Matter. The specification is in the rapid-evolution early phase of its technology lifecycle, and with no offense intended to Espressif Systems, Realtek is the more mature of the two suppliers in this particular product category.

Sound off with your theories and/or broader thoughts in the comments!

—Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

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