I am not sure if this is the proper place to post this question. Please tell me where should i ask this if not.
I am designing a project that is very similar to MSP-WDS430BT2000D kit. My design would need rechargeable battery, be Water-resistant and to have some way to talk to external world without opening it, and be rugged to external enviroment (shower, swiming poll and so on). The current version is using a push-pull transformer in order to create a isolated interface to recharge the battery and iRDA interface to communicate with the external world. That is working and got a good level of isolation and protection. However looking at MSP-WDS430BT2000D specifications, it seems to have a spy-by-wire interface exposed to connect to the clip and exposed pins to charge the battery.
I was looking at some photos at this website (http://sensorseverywhere.wordpress.com/2011/10/04/metawatch-platform-warranty-voided/), and it seems to have not real isolation from the external world. Just clamping diodes as i a can see in the picture. Is that a proper protection for the internal circuit considering that the watch will be used in all enviroments a person can go?
Am i over protecting my circuit?
Regards,