I don't have a Di2, but does the Di2 system even know what chainrings and sprockets you have installed?
With ConnectIQ, you have access to some related information in the Activity.Info object that is passed to the compute() function of a data field, or returned via a call to Activity.getInfo(). There isn't any information about the exact gears that are selected, just the current derailleur position and the number of positions for each. See
I think if you want to do something with the actual chainring/sprocket sizes, you'd have to get that information from the user (via application properties).
You should be able to estimate the gear ratio if you have access to the currentCadence and currentSpeed values and have a good estimate of the circumference of the tire. You should be able to calculate ratios for each gear combination, and then map those ratios to chainring/sprocket sizes.
I don't have a Di2, but does the Di2 system even know what chainrings and sprockets you have installed?
With ConnectIQ, you have access to some related information in the Activity.Info object that is passed to the compute() function of a data field, or returned via a call to Activity.getInfo(). There isn't any information about the exact gears that are selected, just the current derailleur position and the number of positions for each. See
I think if you want to do something with the actual chainring/sprocket sizes, you'd have to get that information from the user (via application properties).
Travis
When you set up the DI2 sensor you can specify the gears you have. I want to be able to get that initial information.
I think my comment in the post above is wrong. The rearDerailleurSize and frontDerailleurSize fields appear to report the size of the sprocket and chainring currently in use. I see no way to get access to the other tooth counts on those that are not currently being used.
