3 ms·
All I want is a tiny display, which does nothing but copies bitmap from the phone once a minute. So there is a bluetooth receiver and nothing else, assuming the
by timonoko 5y ago
All I want is a tiny display, which does nothing but copies bitmap from the phone once a minute. So there is a bluetooth receiver and nothing else, assuming the display module works serially. And ok, it is little annoying, if the clock shows wrong, so you need a timer, which blanks the display every 61 seconds. This should work years without charging, like Sanyo from 1985.
- ungamedplayer 5y agoNot sure you personally get to dictate the laws of physics. How did the Sanyo work around the energy density problem?
- timonoko 5y ago20 khz crystal and Cmos.
- timonoko 5y agoI hereby modify my design and drop the bluetooth module. The communication need not be two-way. I suggest ultrasonics, assuming the phone's speaker is able. Now all energy is consumed in the phone. There will be only the E-paper-module and microphone and some filtering in the watch. Also the refreshing rate can now be faster. If the clock shows only the current date, the battery will last decades. The blanking timer is initiated by the presence of the said sonic carrier, or rather by the lack of it.