Cyclocomp or Garmin or Phone?

The first bike computer I used is B'twin count 8 wireless. I have heard and read that wireless comps show crazy readings when the front lights are turned on, due to interference (not only that. This page says that even going under (high) power lines make the same, but I never heard anyone complaining for power lines, Sreepathi had this problem). However, mine had a different problem - the sunlight syndrome - yes, that's how I used to call it.

This picture is not related to whatever
written here, except the cyclocomp
discussed  (see the handle bar)

Usually my rides started by 6AM. The bike comp used to work exceptionally normal, until that minute, somewhere between 9AM - 10AM comes. It will stop working and the day will pass by with blank screen of comp. Again the comp will start working starting from the minute somewhere between 4:30 PM and 5:30 PM.and it will be in 'exceptionally normal' mode, till the next day's haunted minute arrives. Being lazy, I missed to use the warranty to get it corrected / replaced and now it is lying in home without any use.

At a point, when I started to think, I found out I never really cared about speed. Being a Randonneur, all I wanted / may want while riding are,

• Am I still in the correct route? - there is a saying, ' If you’re riding’ ahead of the herd, take a look back every now and then to make sure it’s still there'. This will hold where ever I am alone on the ride too.
• How much distance left for the next control point?. If possible, with an additional detail - the elevation. Even more ? Wind details will help. Further more? heat and humidity. Ofcourse, except the distance, everything else depends on rider, according to me.. So, I expect the distance left to be shown (Tractalis, the android app which gives the details of the riders in a race - I used it to follow RAAM. It gave the exact location of the riders and the distance left for them to the next control. A bit unrelated here, but I liked it showing the distance left)
• How much time left for closing of the next control point.

Well, I don't think there is a device / application which exactly gives me above details. The maximum option available is, load a gpx file in a device, it can direct / warn if route is deferred, and show the typical performance details like, speed, distance ridden, total time, ride time, etc., 

I may analyze the performance if there is a log available at the end of the ride. The maximum performance detail I may want while riding is, cadence. I am not a rider who is serious enough to care heart rate, power, etc., 

So, when I was thinking of an option, Garmin sensors attracted me, especially, edge 500 and edge 800. But their maximum battery life is 17 hours. So, even for a 300 km BRM, I may need to charge in between the ride it as time for that BRM is 20 hrs. Other challenge is cost - with all the sensors, edge 500 costs 3/4th of my bike and edge 800 costs more than my bike, excluding all the import costs, which is about 30% of the device cost.

Other option, I can use my android phone itself which I carry at times. It has more than all the sensors in the Garmin, (though may be not as accurate, trimmed for the need as garmin). The flexibility here is, I can get an app which can exactly satisfy my above needs and still use it for normal purpose like, calling, taking photos, occasional mail check, etc.,

Now the charging part - since the GPS sensors in the phones are one of the most power draining components, I should get an app which uses it wisely. Requirement is, the phone, should live on battery for 12 hours, with the app using GPS is continuously running, minimal screen usage, very rarely receiving calls and taking photo. Let me state it clear. Consider using a dynamo for all my power needs. Nights, I may be using the power for front and rear lights, and so the phone is expected to live on battery till morning.

I tried with an app called cycledroid, in our last recce ride of 207 kms. That gave me with more details on the ride and gave a nice log at the end, with all the graphs to analyze and option to export gpx. I liked it for following features

• It uses only GPS and no data connection, to find performance data like speed, distance covered, etc., The same drawback of finding elevation through GPS exists here too, though it is due to sensor and not app. Using of barometer in the phone (if available) to find elevation would have been more accurate
• Total Power drained is only 39% of battery over 14 hours in Nexus 5, that too with some calls attended, some photos taken and twice mail checks.

This is not an extensive research on the apps for the need. I just wanted to check, came across this app randomly and it attracted me as well as satisfied me to some extent. There may be apps which use even less power, but I am OK with this as my power requirement is met, for now.

The next check I have to do is, whether my phone can get charged in the remaining 12 hours (daytime - when no lights are used and dynamo power is available).

So, who knows, if no app can satisfy my need, one day, I may learn android programming and try to develop an app myself ;-)