Bike CdaCrr

Bike computer to ride faster by improving your aerodynamic position and testing gear/equipment. Among other data, it monitors CdA (drag*area) and Crr (rolling resistance) coefficients, during races or dedicated testing sessions.
Requires an Android smartphone with built-in ANT+ support (or thanks to an ANT+ adapter) and sensors for speed and power:
ANT+ powermeters currently supported are:
-PowerTap (records speed so additional sensor is not needed)
-Power2Max
-Quarq
-SRM

ANT+ speed sensors currently supported are:
-CycleOps speed sensor
-Garmin speed sensor

Read the help to quickly see how to use the app: http://cdacrr.blogspot.fr/p/help.html

For support or mail, contact us at bikecdacrr@gmail.com

Current features:
-Classic lap mode (default, click each lap) where it is possible to:
-Measure Crr on ridden laps at slow speed (<15km/h)
-Measure CdA on ridden laps at high speed (>25km/h)
-Model uses air density accurately computed with weather station data and detected sensors
-Configurable field to switch between different fields (altitude, cadence, bike direction,...)
-Several CSV files are stored and can be sent by mail for post analysis
-Possible to hear/record voice message each lap
-Possible to activate cloud storage to list/edit previous runs later
-Possible to plot virtual vs real elevation (barometer needed)
-Averaging power on a lap or smoothing it over a duration
-Measure road vibration with phone accelerometer if available
-ANT+ devices Id are stored and searched preferably
-Record also cadence and heart rate from Ant+ sensors

Several checks are done to discard some laps because of bad data:
-Detect data drops (ANT+ events not received)
-Detect zero cadence from a crank based PM
-Detect ANT+ sensor battery status

This version is free, but additional features are possible by switching to the premium version:
Premium features:
It includes other modes (described here):
-Defined lap length mode (for velodrome, click once to start the run)
-Automatic segment mode (needs barometer) to record apparent CdA during a ride (given periodically with 2 digits) which starts each time the minimal speed is reached
-Time trial mode (needs barometer) to compute CdA, power, speed and other average values at the end of a time trial race
And some optional devices:
-Support Weather Meter anemometer to record air speed (to get a higher precision on CdA figures during rides with automatic segment mode)
-Support Garmin tempe sensor to record local temperature (higher accuracy on air density calculation)
-Possible to use Bluetooth headset to hear/record voice messages (very useful during velodrome testing)

Download the key for the premium version here

Known bugs:
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