MySensors Smart Watch

[alowhum]

After a bit of discussion in the nRF5 thread, it might be useful to create a thread specifically focussed on the subject of re-purposing cheap nRF5 smart watches to use as MySensors nodes.

Why would I want a MySensors smart watch?

• If you want a power sipping node with an oled screen and a few sensors.. well you just described a smart watch.
• From a privacy perspective, most smart watches are horribly designed. A MySensors smart watch could offer the advantages of a smart watch without all the cloud connections and bluetooth tracking risks.
• It's cool.

What has been done?
Surprisingly, quite a bit. Have a look here:
https://github.com/micooke/arduino-nRF5-smartwatches/
https://github.com/curtpw/nRF5x-device-reverse-engineering
https://github.com/goran-mahovlic/nRF51_ID107_libs
https://github.com/goran-mahovlic/openwatch

What should I look out for?

• The holy grail would be a smart watch that can be updated via DFU over the air. That way you don't have to open it, which often destroys any waterproofing. Of course this only matters if you want to actually use it as a watch and not, say, as a small tabletop display.
• In some of these cheap devices the heart rate and/or blood pressure devices are very poor quality, meaning you will get eratic results.
• Currently you may need a JLink or Black Magic Probe debugger to gain control over these devices.

Discussion
There is a chat here

Popular devices

• ID107HR - It's an older NRF51, but the advantage is that the screen has been mapped, the pads are clear, and it can be opened with a small screwdriver. It's your best bet.
• ID107HR Plus - NRF52 version. The screen doesn't seem to be mapped yet. It's glued shut, and incredibly difficult to open.

Getting started

• Get or make a Black Magic probe.
• Buy an ID107HR (€15 at Gearbest)

1. Install sandeep's git from https://github.com/sandeepmistry/arduino-nRF5. Do refer to instructions at the bottom of the git to install as a development core (supports Black Magic Probe), i.e. clone/copy repo into 'Arduino/hardware/sandeepmistry/nRF5' folder.
2. Install ARM Cortex support by installing SAMD boards via Arduino Board Manager interface.
3. Overwrite the variants files located in your 'Arduino/hardware/sandeepmistry/nRF5/variants/Generic' folder' using the files from https://github.com/rogerclarkmelbourne/arduino-nRF5-customised/tree/master/variants/ID107HR_smartwatch.
4. Install Goran's git from https://github.com/goran-mahovlic/nRF51_ID107_libs and load up the example sketch of 'SmartyV2ClockOledAcc.ino'.
5. Select the Board 'Generic nRF51' from the 'Nordic Semiconductor nRF5 Boards' menu. Select the 'Black Magic Probe (GDB)' from the programmer menu. Compile/upload.

[dbemowsk]

@alowhum Do you have any specific brands/models that would work, especially with the Black Magic Probe?

[alowhum]

@alowhum said in MySensors Smart Watch:

https://github.com/curtpw/nRF5x-device-reverse-engineering

I haven't tried anything myself yet. The ID107HR is your best best. There's a useful guide here.

[alowhum]

My ID107 has arrived. To open the ID107 you will need a tiny star-shaped 6-corner screwdriver. I've successfully opened it and closed it again, no problems there.

My first goal will be to create an image of the old firmware. But unfortunately I don't have any spare time to work on it right now.

[alowhum]

One of the 2018 Hack-A-Day finalists is a smart watch using the NRF5.

https://hackaday.io/project/144350-hacking-wearables-for-mental-health-and-more

They are using it for medical research.

Here's a video:
Building Wearable Devices the MATTER Lab Way – 15:32
— Curt White

[alowhum]

And it seems there are now watches that can be updated over the air!

SMA-Q2
X9-Pro

More at
https://hackaday.io/project/144350-hacking-wearables-for-mental-health-and-more
https://wiki.hackerspace.pl/projects:sma-q2

[alowhum]

The ID107HR can also be updated over the air apparently.

https://github.com/najnesnaj/ota-dfu-smartband

[alowhum]

Pine is making an open source smart watch running on an NRF52:
https://www.cnx-software.com/2019/09/15/pinetime-smartwatch-companion-pinephone/

[Nca78]

@alowhum said in MySensors Smart Watch:

Pine is making an open source smart watch running on an NRF52:
https://www.cnx-software.com/2019/09/15/pinetime-smartwatch-companion-pinephone/

Interesting, the chinese version is using an nrf52832 too so I guess they will not make too many hardware changes if they want to keep the cost reasonable, adding a better capacitive sensor sound like a great improvement.
I would bet that the screen is one of the ST7789 IPS LCD that are cheap (2$) on AliExpress and have a really great quality. I'm quite tempted to buy the Chinese watch now

I'm very tempted to buy the chinese version right away now

[alowhum]

Has anyone bought a PineTime by chance? They are really progressing quickly, with OTA support and everything.