Teardown: Roku Streaming Stick

Article By : Brian Dipert

Roku's Streaming Stick Model 3500 squeezes an abundance of processing and communications into a few ICs.

Back in May, within a teardown of a “hockey puck” style Roku 1 media streamer, I mentioned that I also had a Roku Streaming Stick Model 3500 sitting in my to-disassemble pile. Here it is (the outer box, at least):

Roku box

Clever tagline on the end, huh? The fun continues after you lift the box lid:

Roku open box

In addition to the streaming stick, there are a few other goodies inside, such as the remote control, a “wall wart” power supply with a USB output, a USB-to-micro-USB cable, a set of batteries, and a smattering of documentation:

Roku remote in box

Roku batteries and cables

Roku wall wart and cable

Roku documentation

The remote control for this particular Streaming Stick model, the 3500XR (also variously referred to as the 3500R and the 3500X), exclusively employs the Wi-Fi Direct connectivity protocol that I’ve complained about before. Apparently, judging from the sticker on the back of the remote control’s plastic wrapper, other users have had problems with the approach, too:

activate Roku remote

Here are some shots of the remote control front and back sides, along with a closeup of the battery compartment on the latter (also showing the pairing button inside it):

Roku remote

Roku remote battery terminals

Indicative of the product’s age, one of the four pre-configured front panel buttons, for Rdio, references a service that went bankrupt four years ago!

Now for the Roku itself, beginning with various exterior perspectives, one also including a penny for size comparisons (for readers outside the U.S., a penny is 19.05mm in diameter). Note the single LED at top to communicate various operating modes to the user:

Roku stick top

This particular unit is a factory refurb, therefore the atypical additional stickers on the bottom:

Roku stick bottom

There are passive airflow vents on both sides along with a hardware reset switch on one of them:

Roku stick vents

Roku stick reset switch

One end connects to the TV via HDMI, while the other connects to the aforementioned USB-to-micro-USB cable for device powering purposes:

Roku stick HDMI

Roku stick power port

Time to dive in! Look back at the bottom side view, and you’ll see a slender gap all the way around it. Inserting a thin flat head screwdriver as a lever and gently prying all the way around the device enabled the bottom of the enclosure bottom to pop right off:

Roku stick inside
And the PCB then lifts right out. Looking first at the initially exposed side of the PCB, a single IC dominates the landscape.

Roku PCB

I guessed that the sticker on it referenced a firmware version and, therefore that it was a flash memory. Peeling away the sticker did bring the manufacturer logo portion of the package markings into view: Spansion (now part of Cypress Semiconductor), suggesting that I’d guessed right on the IC type. But I still couldn’t discern any of the other markings. Stay tuned for more here.

Roku Flash memory

Turn the PCB over and you can see the LED, along with the reset switch and two Wi-Fi antennas (one each for 2.4 and 5 GHz 802.11n, labeled ANTEN1 and ANTEN2), on either side.

Roku PCB bottom

But the bulk of the electronics on this side are obscured by a Faraday Cage. As regular readers of my teardowns may already recall, whenever possible I try to return disassembled electronics devices to a condition where they can still be used by myself or someone else via Goodwill donation. Ripping off the Faraday Cage wouldn’t have satisfied that aspiration. Fortunately, thanks to the TC2-R1008 FCC ID, I didn’t need to!

Roku PCB back no shield

The FCC certification documentation photo above reveals Broadcom’s (also now Cypress Semiconductor’s) BCM43236 2.4 GHz/5 GHz IEEE802.11n MAC/PHY/radio chip. Next to it to the right, somewhat obscured by the metal frame, are two ICs that I suspect are the 2.4 GHz and 5 GHz RF front ends. On the other side is a Samsung K4P4G324EQ 4 Gbit (512 MByte) LPDDR2 SDRAM. And not visible in the photo, I suspect because it’s completely under the frame in the upper right corner of the BCM43236, is the system processor, which Wikipedia documents as being the secretive Broadcom BCM2835.

Perusing the BCM2835 documentation reveals that the SoC was designed to interface with eMMC embedded flash memory modules. And indeed (returning back to the other side of the PCB) Spansion made them; Wikipedia suggests that this particular one is 256 MBytes in size. Mystery solved! Sound off in the comments with your thoughts, please!

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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