Remember what the original suggestion was: have the device wake up for a few seconds once a day and send a message as to where it is (or maybe only send that message if it's not where it's supposed to be).
Considering that a typical bike-mounted gps (Garmin Edge 305, for example) can run for several hours on 3xAA batteries, including gps, cadence, heartrate and speed sensors, along with a continuous display, I think a couple of AA batteries would power this thing for several months or even years, at a few seconds per day. And if you can tie it in to Shimano's DI-2 power pack, it will have its power routinely recharged by the user every few weeks for other purposes any way. IOW, I think it sounds quite practical. Now if we can just figure out a way of getting the signal out of a metal frame like mine... Maybe sneak a wire through a tiny hole in the seat post and attach it to the bottom of the saddle? > -----Original Message----- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of David SMITH > Sent: Thursday, May 13, 2010 8:59 AM > To: gEDA user mailing list > Subject: gEDA-user: OT: Bike Alarms (was: Re: Copper-free > area in footprint) > > John Griessen wrote: > > David C. Kerber wrote: > > > If you've got a carbon frame, you could drop it into the > seat tube, > > > where it would never be seen, and therefore never removed by a > > > thief... > > > > This really does sound like a product since bikes can cost > these days. > > Not to put too much of a spanner in the works, but... > > Where does the power come from? How long would it last > between recharges? > > I can't see much of a market if you have to remove the saddle > and turn the bike upside down to extract the device every > week to recharge the battery, especially if it's sitting > unused in the garage. People will forget to do it, and then > the device is rendered impotent. > > Remember that Li-Ion batteries have a nasty habit of > self-discharging, and if you've gone to the expense of > getting a super-light carbon fibre bike frame, you're > unlikely to want to add lots of weight with a large battery. > > > _______________________________________________ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user