Huawei Watch D is a smart watch at the same time, but also a "wrist ECG blood pressure recorder". Such a surprise product is inevitable to be dismantled by ewisetech. In the early stage, we also had a small experience, a little thick feel, what will it be like to disassemble it?
dismantle
The case is fixed with screws between the case and the bottom case, and when opened, you can see the FPC flex board connecting the motherboard, and there is a protective cover plate and screws at the BTB interface to fix it. The surface of the battery is covered with cushioned foam, and the air pump inflator is equipped with a silicone ring. Between the bottom case and the case is a black waterproof silicone ring.
We first disassemble the bottom case part, first of all, the battery on the bottom case is fixed with double-sided tape. The battery is connected to the heart rate detection module by spot welding, and the surface of the solder joint is reinforced with red solid glue. The heart rate detection module is fixed with a plastic sealing cap and a graphite patch on the sealing cover surface.
The heart rate detection module consists of an FPC flex board + PCB small board, which is fixed in the bottom case with foam glue and double-sided adhesive fit, and integrates a rotor motor and a voice microphone. The wireless charging coil is connected to the PCB board and the flexible board by spot welding.
The heart rate plate integrates 8 heart rate detection sensors on the front and 2 white photoelectric modules in the middle, and a total of 6 LED lamp beads in the module. The back of the heart rate plate has an iron absorbing stone for adsorbing the wireless charging base.
Another part of the watch continues to be disassembled: the watch motherboard, the micro-air pump module, is screwed into the case and connected via BTB. The motherboard adopts an L-shaped PCB board, with a small piece of heat dissipation copper foil on the front, 2 pieces of buffer foam on the back, and a layer of heat dissipation copper foil under the foam and the middle of the shielding cover.
The air pump module is the module that Huawei Watch D pays the most attention to. The micro air pump has a plastic shell on the back, which is fixed with foam glue between the two. The FPC flex board is connected to the pump body by spot welding. An air pressure gauge is integrated on the FPC flex board, and there is a mesh vent hole on the back of the micro air pump body.
The side key flex plate is screwed to the inside of the case, the 2 side keys are equipped with red silicone rings, the FPC flex board is pasted with plastic bases at both ends, and the front of the base has silicone and plastic covers, of which the red silicone becomes a blood pressure detection key. The Watch D features a 1.64-inch full-color AMOLED screen with an NFC coil pasted on the back. A light sensor is integrated on the FPC flex board of the screen.
E Analysis
Motherboard front and back main ICs:
1. Ambiq Micro-Apollo4 Blue-32-bit microcontrol integrated Bluetooth 5.1
2. NXP-SN100T-NFC controller
3. CMJRD11G04G - memory and flash memory chip
4. IDT-P9415-wireless charging chip
5. InvenSense-ICM-20690-Accelerometer and Gyroscope Chip
6. Dialog Semiconductor-DA9168-power management chip
7. 3PEAK-TPA626-Current and Power Supply Monitor
8. 3PEAK-TPM8837-motor driver chip
9. CellWise-CW2218B-fuel gauge chip
10. Temperature sensor chip
The main ICs on the heart rate board:
1. Goodix-GH3220-heart rate detection chip
2. Microphone
3. Compass chip
HiSilicon's chip was not found in the chip scheme of Huawei Watch D. But some domestic chips will also be found, such as:
The watch health monitoring chip adopts Huiding Technology (GH3220), which is a health monitoring chip that integrates multi-channel PPG and single-lead ECG, which can support detection functions such as heart rate (HR), heart rate variability (HRV), blood oxygen saturation (SpO2) and pulse wave conduction time (PWTT), and has ultra-low power consumption and ultra-high accuracy, the chip first appeared in eWisetech's database.
There is also a chip solution in the fuel gauge chip using the Guangdong Sai Violet electronic fuel gauge chip (CW2218B), and the manufacturer's fuel gauge chip has also appeared in the Honor 60 chip solution.
Summary: Huawei Watch D disassembly is relatively simple, the whole machine uses screws and foam glue to fix the internal components, and the watch is equipped with silicone rubber material at each seam to seal waterproof. The design of the chip solution is relatively simple, and only one low-power microcontroller is used in the solution, and no independent central processing unit and RF chip are set up. Huawei Watch D uses The GH3220 detection chip of Huiding Technology for the first time.