There are many discussions about which is the best shape for a smartwatch: Round or Square; and even in the Android world you can find examples for both:
- Pebble Time: Square (Rectangular)
- LG G Watch: Square
- LG Watch Urbane: Round
- Samsung Galaxy Gear Live: Square (Rectangular)
- Sony Smartwatch: Square
- Motorola Moto 360: Round
Apple decided to choose for the Square flavor for all its models of the new product line.
Well, we could debate plenty about who is right or wrong, but here I want to take a look to the insides of the Moto 360 and the trade off in its internal design to make it round.
The first thing that we see inside of it, its is Heart Rate sensor, much smaller than Apple approach, but based in the same methodology known as photoplethysmography.
For your information, it’s theoretically capable of also acting as a pulse oximeter for assessing your oxygen saturation level. However, as far as we know, these enhanced capabilities are not (yet) enabled, neither for the Moto 360 or Apple Watch due lack of 100% accuracy always under all kind of circumstances.
Then, once opened, the first thing that you see is the screen flex cable connected to the main board, which also has an RF shielding on top all the circuitry:
And further, at the other side, its 300mA battery, which is not round at all, unless you doubt about it 😉 ; so limiting its maximum capacity size to the diameter of the round watch:
In the other side of the bottom plastic cover, we can see the inductor for the wireless charging power system, which follows the Qi inductive power transfer standard, (which is most “de facto” nowadays standard):
And then, finally, we reach the PCBA (Top and Bottom views) with all the tiny components reaching all the limits of the round shape at top side:
It is pretty cool (from the electronics point of view 😉 , as Apple Watch made a higher system integration, but also more expensive) to see how the PCB designer used up to the last piece of area.
Moreover, we can identify some of the main IC components on it:
- TI – TMS320C5545: DSP (for Voice processing)
- TI – WL18G/31/46C1VRI: Wireless transceiver module, handling Wi-Fi (but not enabled), Bluetooth, and Bluetooth Low Energy protocols
- Micron – MT46H128M32L2KQ-5 IT: 500MB LPDDR SDRAM
- Toshiba – THGBMAG5A1JBAIT: 4GB NAND flash (e-MMC interface)
- Solomon Systech – SSD2848K1: Display controller (driving the LCD)
- Atmel – MXT112S: Capacitive touchscreen controller
- TI – AFE4490: AFE for the pulse oximeter sensor
- TI – 1211A1: USB 2.0 PHY transceiver (for inner user or debug)
- TI – TPS659120: Power Management Unit
- TI – BQ51051B: Wireless Power Li-Ion Charger Receiver
- Wolfson Microelectronics (Cirrus Logic’s) – WM7132: MEMS microphone
- Wolfson Microelectronics (Cirrus Logic’s) – WM7121: Second MEMS microphone (companion for noise cancelation)
- InvenSense – MPU-6050: Single package MEMS Six-axis accelerometer + Gyroscope
And then one of the cool things is the CPU, which is located just underneath the Micron SDRAM package, which is a TI – OMAP3630, labeled as X3630ACBP:
It is a SoC from some years ago, but with the Software optimized, powerful enough to have the smartwatch’s responsiveness consistently snappy and cheaper.
For instance, Apple developed its own SoC, but for Motorola/Lenovo, this integration approach was cheaper than developing a SoC from scratch, or paying IP royalties to newer CPU vendors.
Besides, for those who remembers that in old days Motorola made their own chips, remember that Motorola spun-off its semiconductor unit (Freescale today, and next year part of NXP); so as you see, they mostly invested in TI chips rather than other suppliers.
Finally, you can see how looks like the circular LCD screen of it:
Although circular screens are not mainstream, we assume this LCD solution approach was cheaper than an OLED option, even taking into account the lighting and power consumption drawbacks of this screen technology compared with OLED.
Well, my last comment will be regarding its ‘ugly’ LCD’s bottom side ‘black line’ characteristic, which you can clearly see in this photo:
There is located the ambient light sensor. And although I don’t know if Motorola (Lenovo) deeply studied another possible location for it; unfortunately, it really destroys all the ‘hype cool‘ thing of having a non-pure UX rounded screen smart watch 😦