Demystifying the Sony Smartwatch

A while ago, I picked up a Sony Smartwatch (the first one) to go with my Android phone, and I used the hell out of it. I unfortunately had to get rid of my phone, which left me with a useless smartwatch.

I'm a programmer (20 years or so of experience, so not just a hobbyist) and I figured I might be able to pair the watch with my Windows tablet's bluetooth and develop apps for it in order to squeeze out more usefulness.

No such luck, the tablet refuses to 'see' the watch and vice versa, so I suspect that the host app for Android has something to do with the pairing process, but I have no idea what.

My first hurdle is to figure out if the two are capable of pairing. I have to assume so, since they both seem to use a standard bluetooth radio (at least the phone had to). And the tablet picks up my bluetooth keyboard just fine.

Does anyone know any details about this, or know where I can find more information? No, the Sony website has no useful information. In fact, it is absolutely useless other than the scant information it has on some of the watch components, a problem I will have to deal with later (eg, it tells me the bluetooth module is 'on pin 3' which at this time tells me nothing about it). I am able to build and upload sketches to the watch using a custom toolchain a third party put together 2 years ago, but that project has apparently long since been abandoned.

I've decompiled the smartwatch app and will be reading through the code literally line by line to see if I can find anything specific to bluetooth and pairing with the watch. I suspect the app does some custom stuff behind the scenes in order to pair with the watch.

I think in the end, I will end up shopping around for a new smartwatch that the community has specifically found to be hackable, and have fun that way. Also, I ran across the Arduino while trying to get this all to work, and fell in love. I'll be getting a Mega next month to start playing with :slight_smile:

Thanks in advance for any information.

Have you tried wireshark or other bluetooth sniffers?

I appreciate the fact that you want to help, but you really need to actually read my post. A sniffer is not going to help me because, as I mentioned, the smartwatch won't pair with the Windows tablet. Second, even if the watch were to pair with the tablet, there is no smartwatch app on the tablet, and thus there is no traffic to sniff. I would need to a) have an android device, which I don't and b) have sniffing software on the android device. Even then, this does not solve the issue I originally posted, which is that the smartwatch isn't pairing with the tablet in the first place.

Thanks for the effort, though.

It's unlikely that Sony wrote their own bluetooth pairing sytem. That would probably require re-writing for each different phone.

Can any of your current devices see the smartwatch as available for pairing? Does it even advertise properly as a bluetooth device? Does Sony tell you the pairing code - is it the last few digits of the serial number on the watch or something secret that only their app knows?

Maybe try looking into an android emulator? I know it wont help your cause very much, but it may be a little progress if you can get that to work :slight_smile:

I'm not sure what was going on, but the smartwatch mysteriously appeared in my tablet's discovery list last night, so I panicked and paired it. Now, it looks like the watch is either trying to transmit something, or waiting for the tablet to transmit something. I think this is the point where I need to delve deeper into the decompiled app code. At the very least, I think I'll be able to hack together a windows based app that'll let me both send/update images to display on the smartwatch and b) receive touch event data... The sensors and vibration buzzer would be nice but I could sacrfice those if I could get the image and touch working. The protocol seems to be a simple opcode/length/payload one, nothing fancy.

Thanks for the suggestions and replies :slight_smile: