One of the smart watches I ordered, arrive from AliExpress yesterday.
The model numbers on these things are really confusing.
The packaging had E05-B05 written on it, on a barcode, so I googled for that and found various listings that also quoted the TW64 model code.
So I initially thought I had ordered duplicates, because of the inaccurate descriptions for these products.
However I noticed the watch I received had a heart rate monitor, but the basic TW64 does not have this feature.
Dissassembly was easy. The core of the watch can be removed from the rubber strap, and the back is held on by 4 crosshead screws.
Inside is a nRF51822QFAC (256k flash, 32k RAM), i.e this is the best nRF51822. The board also has both 16Mhz and 32kHz crystals for good timekeeping and low power operation.
On the back of the PCB are pads labelled for SWD and TX and RX .... To easy
Connecting a JLink revealed the device is read protected (no big surprise), so I had to erase it and then flash the v1.0 (SDK10) S130 softdevice, and I was then able to flash an iBeacon sketch to the watch to confirm BLE etc was working.
I then tried Serial TX and it worked fine (connected to a USB to Serial adaptor)
Goran's test code proved the button pin and vibration pin are also working, and the acceleromter is also working fine.
OLED is almost working, it does display some text but the position is wrong and it keeps moving, which suggests some pixel addressing problem.
I have not started to investigate the heart rate sensor yet, as getting the display to work correctly is the top priority.
And I will post a write up to my blog