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I'm not upgrading £££ of powermeters just to get better battery life from them. BLE >>>
Does it? I thought GLONASS allowed more accuracy not less power. How does it choose between sensors without communicating with both to know either was available? Less sensor, less power, no?
ePaper - how do you do quick updates at junctions? I ride around a RAB glancing at my position to know which exit to take because "take 2nd exit" is usually wrong and fails to include motorway on-ramps as exists!
Tracking. Agree.
etrex already gets ~30hr with Lithiums but I want rechargeable AAs if possible. If they just extended it to read ANT+ and made the processing/screen draw faster and maybe TBT nav they might have something decent.
I'd miss the touchscreen. I like scrolling around to see how lost I am...
hippy-
Does it? I thought GLONASS allowed more accuracy not less power. How does it choose between sensors without communicating with both to know either was available? Less sensor, less power, no?
Signals from more satellites == more processing power required = higher battery drain
GLONASS has fewer satellites than (US) GPS, so it'll generally take less power for similar accuracy (to the level that cyclists care about).
For pure accuracy comparions, GPS is generally going to better than GLONASS.
Signals from both GPS + GLONASS = much better accuracy, but two sets of almanac/epheremis data needs to be cached, etc. And a lot more computation to determine the current location. You also have to power the GPS receiver for each system enabled.
Each system has a different way of limiting accuracy for public use. The US system encrypts the lowest significant bits of the timing signal, with the decryption keys only available in specialist hardware. The ~5m accuracy we are used to in commercial GPS systems is all down to the random jitter caused by these encrypted bits.
The Russian system sends the high precision signal 10 times from frequently than the low precision signal, but the format of the high precision signal isn't known/published, so no-one knows how to make use of it.
Greenbank
Bluetooth instead of ANT+ for sensors like cadence, HR, power and speed. It uses far less battery power. ANT+ would be supported for people who have existing stuff, but it would use more power than BLE stuff.
GLONASS uses less battery power than GPS to track, so running both would allow the device to use whichever is most appropriate for long battery life and accuracy. Should easily go from 14-16 hr battery to 48 hr. This is the biggest battery killer, so also the thing to solve well.
ePaper uses way less power than any lit LCD/LED screen. No reason to constantly scroll the screen, change layout to show distance to next waypoint, key junctions and next waypoint info. Screens are the next bigger battery killer, ePaper is close to negligible power use and would be higher res than the LCDs today (which use low res to save power). If the device were more comfortable with hundreds and thousands of waypoints this type of display would work well.
Tracking, no cleverness to it, no virtual partners or device trying to show it in a certain way... just reliable dump of everything in universal formats.
Should be able to make such a device with a 36-48hr battery life, using standard batteries.
It would be a little uglier than a full colour touchscreen, the interface would be different and again to save power just have buttons rather than a touchscreen. But it could be done, it's totally feasible today.