4 ms·
In bikes these days, they do indeed mean "using EM energy for communication," AND also "no shifter cable." There's a comm link similar to Bluetooth (or maybe st
by rdiddly 7y ago
In bikes these days, they do indeed mean "using EM energy for communication," AND also "no shifter cable." There's a comm link similar to Bluetooth (or maybe straight-up consisting of Bluetooth, I don't actually know) between the shifter controls and an actuated derailleur (or whatever the shifting mechanism is called in this case).
- loeg 7y agoProbably something lower power than BT. These things try to have days of battery life with tiny batteries (e.g., Di2, eTap).
- tinus_hn 7y agoModern Bluetooth can have years of battery life on a cr2032 button cell if all it does is signal some inputs.
- loeg 7y agoWhat kind of IC do you have in mind for that kind of lifetime? While signaling, say, twice a minute on average, 2 hours a day?
- tinus_hn 7y agoI have no idea how it’s built but I’ve seen it work in practice. This kind of device works for years on a small battery, signaling every rotation of your wheel to your phone as you cycle: https://s.click.aliexpress.com/e/Mv9PcDu8 https://s.click.aliexpress.com/e/Mv9PcDu8
- loeg 7y agoThe spec page says 500 hours of battery, which is about 20 days. At 2 hrs/day that's 240 days -- still quite a bit, but yeah.