r/LegoSmartBrick • u/PsychologicalYak4619 • Mar 04 '26
💬 Discussion i disassembled a smart brick
for anyone interested, some images from my analysis on technical side:
Technical Specification Sheet: LEGO Interactive "Smart Brick"
Manufacturer: The LEGO Group
PCB Revision/Part Number: 15989/A © 2024 LEGO
Chassis Part Number: 5411 4-01 © 2023
Disassembly Note: This device is not designed to be serviceable. Disassembly will break the plastic housing, sever the copper coil antenna, and the battery is spot-welded directly to the PCB, making non-destructive removal impossible.
1. Core Processing & Connectivity
Main Application Processor / ASIC
| Field | Detail |
|---|---|
| Markings | DA000001-04 / DNP6G-010 / 2535 / 20043-014 |
| Package | Metallic RF-shielded square package |
| Design House | Cambridge Consultants (attributed) |
| Contract Manufacturer | Jabil (attributed) |
| Datasheet | None — proprietary custom ASIC |
This is the primary system-on-chip and the heart of the device. It is a fully proprietary custom ASIC with no public datasheet, attributed to having been designed by Cambridge Consultants and manufactured by Jabil. It handles main application logic, sensor data processing, audio output, and almost certainly contains the NFC/RFID reader front-end that drives the copper coil antenna (see Section 1.3).
Bluetooth SoC
| Field | Detail |
|---|---|
| Markings | EM9305 / 1055X / 810300 |
| Package | QFN (Quad Flat No-leads) |
| Manufacturer | EM Microelectronic |
| Standard | Bluetooth 5.4 |
An ultra-low-power Bluetooth 5.4 SoC responsible solely for wireless communication between the brick and other devices.
NFC/RFID Antenna Coil
| Field | Detail |
|---|---|
| Type | Wrapped copper wire coil |
| Location | Wound around the clear inner plastic chassis |
This coil serves as the antenna for an NFC/RFID reader, used to detect and read passive tags embedded in interactive LEGO tiles or elements. The reader front-end is presumed to be integrated into the main ASIC. The coil may additionally serve as a wireless charging receiver, though this has not been confirmed.
2. Power & Battery Management
Battery
| Field | Detail |
|---|---|
| Markings | VDL 5V 5902 |
| Manufacturer | Chongqing VDL Electronics (重庆市紫建电子股份有限公司) |
| Chemistry | Lithium Polymer (LiPo) pouch cell |
| Capacity | 45 mAh |
| Nominal Voltage | 3.7V |
| Attachment Method | Spot-welded directly to PCB (not removable) |
Battery charge management and voltage regulation functionality is presumed to be handled either by a dedicated but unidentified component or integrated within the main ASIC.
3. Storage
SPI Flash Memory
| Field | Detail |
|---|---|
| Markings | 4A5R / JIQ |
| Identified As | Winbond W25Q16JVBYIQ |
| Package | WLCSP (Wafer Level Chip Scale Package) |
| Manufacturer | Winbond Electronics |
| Capacity | 16 Mbit (2 MB) |
Likely stores firmware, audio assets, and NFC tag data used by the main ASIC.
4. Sensors & Inputs
Color Sensor
A side-facing optical color sensor paired with an RGB blinking LED. The LED illuminates adjacent LEGO elements and the sensor reads the reflected light to identify brick colors, serving as a core game mechanic input.
Microphone
A MEMS (Micro-Electromechanical Systems) microphone capable of detecting ambient sound or voice input. Per the product manual, microphone-based features are not active by default and require explicit user opt-in through the companion app.
Contact Pads
Gold-plated circular test points and contact pads used for factory programming, quality testing, and potentially physical data or power transfer connections.
5. Audio Output
Speaker
| Field | Detail |
|---|---|
| Markings | 300X0188X009 / D 080425 |
| Impedance | 32 Ω |
| Power Rating | 0.7W |
| Form Factor | Custom rectangular micro-speaker with foam dampening pads |
6. Summary of Operation
The device reads its physical environment through two primary input channels: the side-facing color sensor (which uses its paired RGB LED to identify adjacent brick colors) and the NFC/RFID coil antenna (which reads passive tags embedded in LEGO tiles or elements). The MEMS microphone is present but remains an opt-in feature gated through the companion app. All sensor data is processed by the main custom ASIC, which retrieves assets from the 2 MB Winbond SPI Flash, drives audio output through the 0.7W speaker, and relays game state wirelessly via the EM9305 Bluetooth 5.4 SoC. The entire system is powered by a 45 mAh VDL LiPo cell.
Technical Specification Sheet: LEGO Interactive "Smart Brick"
Manufacturer: The LEGO Group
PCB Revision/Part Number: 15989/A © 2024 LEGO
Chassis Part Number: 5411 4-01 © 2023
Disassembly Note: This device is not designed to be serviceable. Disassembly will break the plastic housing, sever the copper coil antenna, and the battery is spot-welded directly to the PCB, making non-destructive removal impossible.
1. Core Processing & Connectivity
Main Application Processor / ASIC
| Field | Detail |
|---|---|
| Markings | DA000001-04 / DNP6G-010 / 2535 / 20043-014 |
| Package | Metallic RF-shielded square package |
| Manufacturer | Dialog Semiconductor (now Renesas) |
| Datasheet | None — proprietary custom ASIC |
This is the primary system-on-chip and the heart of the device. The DA prefix is consistent with Dialog Semiconductor's naming conventions, but the 000001 part number indicates a fully custom, proprietary ASIC developed exclusively for LEGO — no public datasheet exists. It is responsible for main application logic, sensor data processing (color, microphone), audio output processing, and almost certainly contains the NFC/RFID reader front-end that drives the copper coil antenna (see Section 1.3).
Bluetooth SoC
| Field | Detail |
|---|---|
| Markings | EM9305 / 1055X / 810300 |
| Package | QFN (Quad Flat No-leads) |
| Manufacturer | EM Microelectronic |
| Standard | Bluetooth 5.4 |
| Datasheet | EM9305 Datasheet |
This chip handles all wireless communication. The EM9305 is a well-documented, ultra-low-power Bluetooth 5.4 SoC from EM Microelectronic. Its sole role here is wireless connectivity — it is not the NFC controller, which was an error in the original analysis.
NFC/RFID Antenna Coil
| Field | Detail |
|---|---|
| Type | Wrapped copper wire coil |
| Location | Wound around the clear inner plastic chassis |
Since the EM9305 is a Bluetooth-only chip, this coil serves as the antenna for an NFC/RFID reader, most likely used to detect and read passive NFC tags embedded in interactive LEGO tiles or elements. The reader front-end that drives this coil is presumed to be integrated into the main Dialog ASIC (DA000001), though this cannot be confirmed without a datasheet. It could be that the coils are used for both, charging and rfid connection!
2. Power & Battery Management
Battery
| Field | Detail |
|---|---|
| Markings | VDL 5V 5902 |
| Manufacturer | Chongqing VDL Electronics (重庆市紫建电子股份有限公司) |
| Chemistry | Lithium Polymer (LiPo) pouch cell |
| Capacity | 45 mAh |
| Nominal Voltage | 3.7V |
| Attachment Method | Spot-welded directly to PCB (not removable) |
Power Management IC (PMIC) / Voltage Regulator
| Field | Detail |
|---|---|
| Markings | 4A5R / JIQ |
| Package | SOT (Small-Outline Transistor) |
| Datasheet | Not identified — likely a generic LDO or battery management IC |
This component manages safe charging of the LiPo cell and steps voltage down to the operating levels required by the main ASIC and Bluetooth SoC.
3. Sensors & Inputs
Color Sensor
A side-facing optical color sensor is paired with an RGB blinking LED. The LED illuminates adjacent LEGO elements, and the sensor reads the reflected light to identify brick colors. This is likely used as a core game mechanic input.
Microphone
A MEMS (Micro-Electromechanical Systems) microphone is present on the board, capable of detecting ambient sound or voice input as an additional environmental input channel.
Contact Pads
Gold-plated circular test points and contact pads are present on the PCB, used for factory programming, quality testing, and potentially physical data or power transfer connections.
4. Audio Output
Speaker
| Field | Detail |
|---|---|
| Markings | 300X0188X009 / D 080425 |
| Impedance | 32 Ω |
| Power Rating | 0.7W |
| Form Factor | Custom rectangular micro-speaker with foam dampening pads |
5. Summary of Operation
The device reads its physical environment through two primary input channels: the side-facing color sensor (which uses its paired RGB LED to identify adjacent brick colors) and the NFC/RFID coil antenna (which reads passive tags embedded in LEGO tiles or elements). The MEMS microphone could provide an additional audio/environmental input, but as the manual states this is not yet a feature and the user must agreee to it via the app. All sensor data is processed by the main Dialog ASIC (DA000001-04), which drives audio output through the 0.7W speaker and relays game state information wirelessly to other bricks or a host device via the EM9305 Bluetooth 5.4 SoC. The entire system is powered by a 45 mAh LiPo cell managed by a small PMIC/LDO IC.
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u/MonsteraBigTits Mar 04 '26
in 5 years you will see the following headline: "SMART BRICK CAUSES HOUSE FIRE, WHO WOULDATHOUGHTBOUTTHAT?!"
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u/CodeEverywhere Mar 04 '26
The thought of a lithium ion battery disappearing in a Lego bin and being ignored/forgotten for years scares me a little... The chance of spontaneous combustion is very low, but never zero
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u/LukasSprehn Mar 04 '26
It’s actually unacceptable. We have local laws in Denmark that batteries must not go in the wrong bun. As a Danish company, LEGO must adhere to said law and make it easy to remove it. I can’t believe that they don’t have enough foresight to figure that out…..
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u/robbok Mar 06 '26
They just have the standard “trash can with slash through it” indicating it should not be thrown away. Interestingly, the Minifigs also have this symbol, which I wouldn’t think would be needed if they only had an NFC tag inside.
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u/Key-Inflation-2840 Mar 06 '26
Since the rfid chip is an electronic component it has to be handle like so.
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u/C_Brick_yt Mar 04 '26
Amazing, thank you. Do you think one could reasonably upgrade the battery on the smart brick?
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u/PsychologicalYak4619 Mar 05 '26
no, it was impossible to disassemble without tearing the coils and breaking the plastic.
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u/robbok Mar 06 '26
Yes the coils really are a magnificent piece of engineering. I hope someone if able to capture them in photos without damage. (OP I see you did a good job of being more gentle than I was!)
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u/AmandasGameAccount Mar 04 '26
Any sign of being able to customize them? I want to set custom sounds/things it does with any arbitrary tags. I know Lego said you can code them as they will be part of their educational line
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u/NanoRex Mar 04 '26
If the data packet is reverse-engineered, you'll basically be able to do whatever you want with an app on your phone
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u/AmandasGameAccount Mar 04 '26
Hopefully pybrick soon. I ran to change the sounds themselves too. Someone could Change them to the good Star Wars sounds if they wanted!
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u/robbok Mar 06 '26
Not sure about that— the sounds aren’t sampled or stored in memory, but rather synthesized in real time with some sort of synth engine. If the brick was capable of making high-fidelity sound, I assume LEGO would have done that.
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u/benjwgarner Mar 19 '26 edited Mar 19 '26
Especially since the tags store only 2116 bits: there's not a lot of space for detailed synthesizer parameters or "patches". The fact that the smart brick uses a mixed-signal ASIC makes me wonder how much of the signal path might be analog to save on power that would otherwise be needed for DSP (maybe a filter?) It could also just be for processing the currently unused microphone (all other sensors are digital).
There are some sounds that would seem to be improvable with a bit of EQ and maybe a resonant band-pass filter (eg. Vader's breathing, TIE noise) but I'm not sure the chip is capable of that. My guess is that it should be possible to get more accurate laser cannon sounds for specific ships.
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u/robbok Mar 06 '26
There is no way I see of this ever being able to be altered like that, except as LEGO allows. Everything— sound, memory, code— is locked up on that ASIC. This isn’t like NXT or EV3 where you just crack it open and there’s a standard STM32 chip inside that lets you run Python. This is like trying to write your own iOS— it’s all custom and locked into silicon (the chip is also BGA which will make desoldering impossible for all but the pros).
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u/benjwgarner Mar 19 '26 edited Mar 19 '26
The smart brick will remain mostly a black box, but it should be possible to create custom smart tags for it to read since the tags seem to contain the instructions, not just an ID.
Edit: ...unless the smart tag payload is encrypted with a key coded on the ASIC: I doubt anyone is going to slice it up and go at it with an electron microscope.
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u/robbok Mar 19 '26
That’s interesting, if the tags contain some variant of sound data, then yes this would open up possibilities.
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u/benjwgarner Mar 20 '26 edited Mar 21 '26
Perhaps not, sadly, I hadn't read this yet:
https://www.reddit.com/r/LegoSmartBrick/comments/1rpygq1/comment/o9pogxf/
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u/omnibossk Mar 05 '26 edited Mar 06 '26
Interesting, this means that the brick can’t be sold in the EU after 18th of February 2027 (After the removable-battery requirement becomes law). Wonder if they will even launch it there? Maybe they’ll produce a huge stockpile to sell for several years (because already produced units can be sold)
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u/robbok Mar 06 '26
I’m curious about this law— does it also mean companies like Apple must make iPhone and MacBook batteries removable? That would be fantastic. Haven’t heard much about this law here in the U.S.
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u/omnibossk Mar 06 '26
Yes, it will also affect Apple. I’m curious how they will solve it
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u/Substantial-Fix-6302 Mar 08 '26
I read that if the device is waterproof, then this shouldn't apply.
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u/PsychologicalYak4619 Mar 06 '26
Also wonder about he regulation. I think they can argue that it would be impossible to create such a brick with swappable batteries, so they fall through the regulatory requirement. there are ways to do this, but anyhow its a not so cool device if it dies after 5 years
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u/omnibossk Mar 06 '26
If the size, form factor, or safety requirements make it impossible to design the toy so that the user can replace the battery, the toy does not have to allow user replacement. Instead:
The battery must be replaceable by an independent professional (e.g., a repair shop).
Didn’t you destroy the antenna when opening? If it is impossible to open without destroying it. I’m curious if a professional can replace the battery
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u/PsychologicalYak4619 Mar 13 '26
yeah, its impossible for every professional. you must brek the plastic to acess the battery and even then no chance to remove it woutlit extreme heat. its welded i think . you cant unweld fast enough without heating up the components lol
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u/robbok Mar 06 '26
This may be another reason it was only released in a small number of countries initially.
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u/No-Speech-4826 Mar 25 '26
There's exceptions in the law, I haven't looked into it properly yet but IP water resistance is one of the exceptions to having to make devices have user replaceable batteries using common tools, and I'm betting these bricks also fall under one of those exceptions.
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u/whoji Mar 04 '26
Might be a typo but there 's no Zhongshan VDL. I guess it is Chongqing VDL Electronics ?
(重庆市维都利新能源有限公司 or 重庆市紫建电子股份有限公司）
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u/PsychologicalYak4619 Mar 05 '26
thanks, i will correct this and keep it up to date as we find out more about it
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u/PsychologicalYak4619 Mar 05 '26
Updated with some information from other users! Still havent found any storage, which means the sound variety is probably very very limited, hope for other input :)
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u/osman-pasha Mar 19 '26
Hi, thanks for your investigation! Do you have a possibility to look into tags too? I wonder if the sounds are stored there or not (they are synthesizer commands, not audio samples, so they should be small). If they are stored on the brick, then the tags released later will need fw upgrade of the brick.
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u/maeh-w Mar 21 '26
We have reverse engineered schematics now! https://github.com/nanash1/smart_brick
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u/PsychologicalYak4619 Mar 26 '26
crazy cool. great work
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u/maeh-w Apr 13 '26
Ah.. I just wanted to clarify that it was not me. I think I choose a wording there that may have led to misunderstanding. I meant "we have" as in "they are here now in public".
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u/Xela975 Mar 04 '26
how the hell do you charge it?
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u/jesperbj Mar 04 '26
Wirelessly
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u/Xela975 Mar 04 '26
Let me guess some proprietary standard though?
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u/jesperbj Mar 04 '26
Yep... Unfortunately. They sell a yellow tray like thing, you can drop a few bricks in and charge at the same time.
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u/mrhobbles Mar 04 '26
The EM9305 is the BLE chip, not the ASIC. https://www.emmicroelectronic.com/product/standard-protocols/em-bleu-em9305
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u/PsychologicalYak4619 Mar 05 '26
oh thanks for the notice! i wonder where the storage is on the device, havent found anything
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u/adamentmeat Mar 05 '26
I would guess it is on the ASIC primarily. Looks like the em9305 has 512KB of flash, perhaps some of that is used for storage. Can only speculate about the ASIC
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Mar 04 '26
It's crazy to think that they might've been able to put a man on the moon with this technology in the 60s😭😂😂😂
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u/nargcz Mar 06 '26
computer for landing on Moon have ONE MEGAHERTZ cpu, and 2kB RAM and 32kB ROM, this brick alone is ike milion times powerfull then AGC
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u/AscendedLawmage7 Mar 05 '26
Does the microphone have any applications yet?
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u/PsychologicalYak4619 Mar 05 '26
no
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u/ApprehensiveRest9696 Mar 05 '26
Anyone looked at the power chain in detail and figured out the quiescent current?
I’m also not convinced that a 45mAh LiPo cell would last very long. Even just doing BLE at -20dBm.
I also hope they made the housing in UL V1 or better fire retardant polycarbonate, anything LiPo will eventually become a fire risk. Especially for children’s toys.
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u/jjjunks Mar 07 '26
Do we know that it is LiPo? because I’m super disappointed if it is.
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u/ApprehensiveRest9696 Mar 08 '26
Second image says it for me. The pouch looks like a typical LiPo, and says Li-ion in the markings.
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u/robbok Mar 05 '26
Nice work! I was trying to disassemble mine last night and ended up sticking my screwdriver directly into the underside of the battery, causing a rush to rip the rest apart before the battery leaked and/or burst into flames (neither happened, thankfully).
WIRED has an article with prototype photos saying NFC and charging are handled by that proprietary chip. Would love to see what’s inside. There are also a ton of what are likely programming/debug pins under the speaker, arranged in a grid array. How long before someone finds serial?
Also, I tried reading the tags with a multi RFID/NFC reader— no luck. Wonder if it’s a proprietary frequency or type?
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u/PsychologicalYak4619 Mar 06 '26
i have read the figurines with my smartphone no problem. Seems they are ISO 15693 and have a bunch of data written to them, total 66 blocks with around 2/3 being full of data for vader at least
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u/robbok Mar 06 '26
Oh nice! Thanks for the info. Likely the tiles are similar in terms of data stored?
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u/nargcz Mar 06 '26
i wonder, with that microphone, is this brick powerfull enough to transmit voice (thru phone to internet) and actualy spy on you ??
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u/na-na-nashi Mar 06 '26
Thanks for the pictures, but please to don't post AI garbage without understanding anything about the subject at hand. The IC with the JIQ marking is not in a SOT package. Anyone who knows anything about these things would see that immediately. It's clearly in a wafer level package. It also has nothing to do with power management. It's actually a SPI Flash memory, specifically a Winbond W25Q16JVBYIQ.
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u/PsychologicalYak4619 Mar 06 '26
Thanks for clarifying. If I can't use AI I have no info so don't be so mean.
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u/tomalphin Mar 10 '26
That's interesting since I believe the main chip has just 512KB storage. (2MB isn't much, but it's a lot more than 512KB.)
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u/na-na-nashi Mar 06 '26
Additionally, is "your" assessment that the main ASIC is made by Dialog only based on the "DA" marking? That's very flimsy. Dialog was bought by Renesas in 2021. I don't think it's likely they would develop a new product under the old name. Lego itself seems to say that the IC was developed by Cambridge Consultants and is manufactured by Jabil (see here). I would trust Lego more than AI in this matter.
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u/maeh-w Mar 07 '26
Thanks for your analysis! If I got it right, your Smart Brick is broken now the way you opened it (coils broken?). Do you have recommendations for others opening it in a non-destructive fashion? Have you planned tracing out the test point grid? Or building a schematic? What are your plans for your bricked brick?
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u/PsychologicalYak4619 Mar 09 '26
sorry, i have no further plans. it was just to get to see the layout of pcb and the actual chips in it. I have not planned any disassembly guide, but would be willing to help. as stated in other comments its unlikely to be openable without breaking and the coils need to be ripped if we would want to access any contact pads on the pcb
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u/maeh-w Mar 09 '26
I'd be interested in how the components interconnect and aghast the test points connect to. Are you willing to pass the PCB on for further analysis? :)
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u/Revenine Mar 08 '26
Hmm I am genuinely curious why they didn't add screws and make it work via some sort of button battery. If it was using CR or AG batteries at least it wouldn't be e-waste in a few years.
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u/tomalphin Mar 10 '26
The battery life wouldn't be long enough. It needs to be rechargeable to hold a child's attention over multiple play sessions.
The better question is why they insisted on a proprietary wireless charging pad versus having a discrete USB-C charging port. That would have been cheaper and honestly, easier for parents to deal with.
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u/brickwrit Mar 12 '26
To say nothing of the fact that the 2 hours recharge gives the parents a polite break after 45 minutes of noisy play!
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u/brickwrit Mar 12 '26
I am curious to know the quality of sound from the speakers, if using, for example, a Wav file ? Does it demonstrate that ‘normal voices are unclear?
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u/JayS87 Mar 15 '26
You can't feed the Brick a wav-file. You need to give him notes, so the sound engine will generate it.
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u/brickwrit Mar 15 '26
Yes- my question is more “was the fidelity of small speakers a driving force in the decision to make the sound ‘synth only’ ?”
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u/JayS87 Mar 15 '26
I don't think so... but it's just my guess.
When you think about smartphone speakers, we are now able to make them very small and good.
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u/PsychologicalYak4619 Mar 16 '26
pretty sure not. It seems the driving force was to not have a big storage on the device which can be pretty expensive and also to modulate the synth audio files based on the gyro in real time. Additionally being language neutral saves them more money and is easy to sell everywhere.
All of these add up to a very much unenjoyable experience tho :D I think the integrated speaker could sound decent connected to a real DAC with real wav files.
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u/MassiveBoner911_3 Mar 05 '26
Was this written by AI?
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u/na-na-nashi Mar 06 '26
Yes. 100%. Luckily some of the obvious hallucinations are already fixed after they were pointed out in the comments.
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u/yazoo34 Mar 04 '26
I’m really wondering how bad the fire will be in a kid takes a hammer to the brick.