You are reading a single comment by @stewartg and its replies.
Click here to read the full conversation.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@stewartg
OK, thanks for the information. I had a look at the disassembly video, and a few ideas come to mind. Part of the reason the speaker is not loud may be that it is not well coupled to the case of the watch. In its normal position, the heart rate sensor and a layer of plastic film is between the speaker and the case. One solution might be to stick the speaker directly to the back of the case. It would have to avoid the existing sensor window and connector pins. Piezos come as small as 12mm, so a couple of these might fit, or alternatively could be cut down to size. Adding an air hole might also increase the loudness, at the expense of some water resistance. Another solution might be to stick the speaker inside the front of the watch. A blind user can't see the LCD anyway so there is no great loss in sacrificing all or part of the front display area.
I will go ahead and order a couple of watches to experiment with. Is it possible to buy extra cases? This could be useful in case I break something while tinkering.