In the past 3000 miles of riding, I power up the 820, give the pedals a spin, and the edge immediately offers to Calibrate my Stages power meter.
Since upgrading to version 8.4, it is very slow to do so, if ever. It will sometimes ask to calibrate after my ride has started, or after I have already calibrated manually. I don't see a consistent time period for the offering. It might happen right away, or in 30 seconds or (in test just made) 2min 15 seconds,
The Indicator icon shows that the power meter has been detected and acquired. Calibration offer time is highly variable. Sometimes no offer at all. If powermeter is off when Edge is powered up, Edge recognizes/acquires the power meter immediately after crank is moved, but still take a variably long time to offer calibration, Stages Firmware V2.0.82 - new battery Garmin software version 8.4 Garmin Vario Radar tailight
Garmin HRM and speedo.
I have one other complication. I have two Stages Power meters on different bikes. Is this causing the problem?
The Edge is likely looking for a given message type from Stages before it offers the calibration prompt. I would suspect the capabilities message so that it knows what features the power meter supports.
Stages may not be transmitting that message frequently enough, so if you just missed it when the Edge connects you have to wait until it comes round again in the message cycle. Hence the variability you are seeing in the timing of the prompt appearing.
As I said in the original post, I have 3000 miles of riding where there is no delay. It didn't start until V8.4.
I further reported that the status icon showed the Edge recognizes and acquires the powermeter *instantly*. I.e. the icon stops blinking. In case you are a newbie or one of those posters who relies to everything even when they have no experience, this means that the edge has found and identified the powermeter, as a powermeter. Hence it has nothing to do with the powermeter.
This is clearly, unmistakably a Garmin issue with V8.4
The Edge has found the power meter, it is not a connectivity issue. The Edge is waiting to get a message from the power meter that contains certain information before it offers the calibration prompt. This is likely a change that Garmin introduced in 8.40.
The point aweatherall (the newbie with 8900+ posts over 8 years :D) is making isn't about whether the power meter is recognised instantly or not - different power meters have different capabilities (and needs - some don't need calibration, some don't support calibration) - if the Stages only transmits it's capability message via ANT+ once every 10 seconds, then there may be a delay in the Edge responding to it (admittedly it does seem that the behaviour of the Edge has changed in this case)
There was a change made to support Vector that shows the crank length when the calibration prompt is offered. To show what the current length is the prompt is held until the Edge gets this information from Vector.
I believe that the ANT spec specifies what the longest period is between these messages being sent by the power meter.
If I get a chance today I will log the radio traffic from a Stages power meter that I have and see how frequently this message is sent.
Definitely a delay on the Edge 820 that was not there previous I active the power meter fire up the 820 and wait for the calibration screen it used to be instant. My edge 520 still shows it instantly :)
The Edge is looking for the manufacture information. The ANT+ power profile requires a power meter to send this at a minimum of every 30.25 seconds. A vendor can choose to send it more frequently if they wish. So the worst case should really only be 30 seconds after the Edge has established communication with the power meter.
So the next step is to see how frequently Stages are sending this data.
So when I boot my Edge 520 and Edge 820 at the same time and the 520 prompts for calibration right away and the 820 has a 10-20 second delay, shouldn't they be close?
Maybe I'll shoot a short video tonight of the two.
