So, to follow up from my previous post. I have a Garmin speed and cadence sensor working with my Samsung Galaxy S2. It took a little bit of fiddling to get it working and ultimately it's probably not the most elegant solution, however it is workable as an alternative to buying a Garmin bike computer.
In addition to your phone you need:
HARDWARE:
Garmin ANT+ USB dongle
OTG Cable
Bike Mount for your phone - I bought a dodgy one off eBay
ANT+ Sensors
SOFTWARE:
IpBike
IpSensorMan
ANT Radio Service
ANT USB Service
SiyahKernel
GETTING IT TO WORK:
I went with the Garmin ANT+ dongle and the Garmin Speed/Cadence sensor. I figured that if I couldn't get them to work with the phone, then I could just buy a Garmin device and the bits that I already had would still be useful. An OTG cable is also a handy thing to have for your phone, since you can use it to connect to USB thumb drives and the like. Also, having a bike mount for the phone might be a handy thing to have as well.
Once you have all the hardware, the fun bit was getting it all working. I installed IpBike, IpSensorMan, ANT Radio Service and ANT USB Service but I couldn't get the default kernel to work with the USB ANT+ stick. I believe it's missing the necessary hardware support. So I had to
root the phone and install the SiyahKernel. If you're going to do this I would recommend reading up on the process and ensuring that you have a backup of your stock ROM. There's always an outside chance that you could
brick your phone - I accept no responsibility if you do so!
Once I had the phone updated and the software installed, it all pretty much just worked. It does rely on having Bluetooth enabled (or is it wifi?) so if you forget to enable it you won't be able to connect to your sensors. At least once I've set off on a ride and then noticed that there was no cadence display because I still had Bluetooth turned off.
HOW GOOD IS IT?
Well, as you can see from the photos below the Galaxy S2 is a big, chunky device when compared with a standard bike computer. The holder I have is slightly oversized and fits the phone even when it's still in a gel cover. The holder also isn't fully waterproof and the screen can be hard to read thanks to the reflective plastic. In bright sun it can be hard to really see the screen properly. Battery life has actually been a bit better than expected. After a few hour's there's still plenty of battery charge left. If battery life was a real concern then a larger capacity battery or a
power pack could be an option.
The IpBike Man software feels a bit clunky at first, but once I got it set up and working I was happy enough with it. When I've finished a ride I IpBikeMan can upload it to Strava for me. I think there's a few other sites that it will upload to as well. Or I could download the GPX file to somewhere.
Some photos:
Big, chunky phone and reflective plastic.
OTG cable and Garmin ANT+ dongle zip tied to the stem.
Standard Garmin speed/cadence sensor.
CONCLUSION:
All in all I was happy that I was able to get ANT+ sensors working with my phone. There are some downsides, and I suspect that a Garmin Edge 500 might be on the cards now that they've dropped in price with the release of the 510. Plus I already have the sensor and a USB dongle to upload my rides.