Ok. I am getting back into cycling. (got to lose weight)
anyway I am finding out there are a lot of neat "gadgets" you can get for bikes. Data aquisition is fascinating.
they have devices to let you capture your speed, cadence, power etc.. etc.. collate that with GPS data etc.. upload to sites like icardio and strava etc..
so I have been trying to get the sensors and widgets I need. I want to use my droid. makes perfect sense its powerful enough has the gps and data connection and is powerful.
dedicated sensors are cheap enough $5 to $40 a pop
but I want to log all this on the android. they HAVE this. heart rate monitors, cadence sensors, speed sensors, power meters etc.. etc..
the only problem is all of its ant+ or btle (bt4) which means most of us simply don't have the "reciever" since most phones are bt3 or lower not bt4. only the newest most expensive droid for the most part "have" this stuff yet.
so I can't use it. Grrr.
I got to thinking most of this stuff is actually really cheap. just no one has put it all together yet and it written the software for it.
So I am wondering if this kind of project is possible.
the concept is this. most of the sensors are just magnetic switches. you put the switch on the frame and a magnet on the wheel and crank.
every time the magnet passes over the switch you get a pulse.
add time and you now have RPM. for cadence this is enough. pulses per minute (rpm) is your cadence.
for speed we need a tiny bit more. tire circumference. add rpm and tire circumference and you have speed. so most of this can be done IN SOFTWARE in the droid. the guinino would just need to send the "rpm" information and the software would interpret that into usable data.
would also be nice to have a barometer inside to get more accurate elevation change information.
the idea is you have a brain box on the bike (run off say 18650 cells) you run sensor leads to this. in software you simply have data on channels and you "tell" it ok this channel is speed this channel is cadence etc..
this brain box would have bluetooth and send its data to the phone application. it would then process that data and display information.
other interesting things it could do. control lights? ie trip a relay if you press a button on the screen. maybe even use the light sensor in the phone to turn them on automatically? or use geographical sunset data to trigger the lights at the right time. etc..
How hard would this be to get done? is anyone with the skills willing to work on it? what about the software? (I can do basic soldering etc.. and I can assemble stuff but I can't design and I can program)
what do you guys think? there are already "regular" bluetooth heart rate monitors so we don't have to mess with that.
this would allow ANY droid phone to "do" these functions and not just high end phones.
i would want to make the data available on the android to "any" program. API ?? so other software can "tap into" this data to use for its own. ie universal.