PM offset 2 devices

chatlow
chatlow Posts: 850
edited April 2019 in Road general
Hi,

I am just about to get a powertap p1 dual sided PM. Will be pairing this with both my elemnt bolt and also my fenix 5 so it saves to garmin.

What I need to know is when setting the offset / calibration before each ride, I assume I need to do this on both the watch and headunit?

Please let me know!


Thanks

Comments

  • zeee
    zeee Posts: 103
    As far as I am aware you are calibrating the pm. You just do it via the head unit. Therefore you only have to calibrate it once per ride regardless of how many devices you have it connected to.
  • chris_bass
    chris_bass Posts: 4,913
    as above - the offset value is sent to the power meter so you just need to do it on one device
    www.conjunctivitis.com - a site for sore eyes
  • chatlow
    chatlow Posts: 850
    i did wonder. makes sense. thanks both!
  • chatlow
    chatlow Posts: 850
    fenix found both left and right sensors individually, but elemnt bolt found them as just one. hope that's normal. Calibrated using the bolt. No option to set the crank length on the bolt so had to use fenix for that part.
  • chris_bass
    chris_bass Posts: 4,913
    depends on if it is pairing via ant+ or bluetooth - i have Favero Assioma Duos and in the app you need to set it to broadcast both channels via left pedal and that sorts it.
    www.conjunctivitis.com - a site for sore eyes
  • zeee
    zeee Posts: 103
    From powertap:

    Basically, there is a fundamental difference in the way the two communication protocols operate. With ANT+ the pedals are connected to each other in a master/slave relationship. The pedal that serves as the master, the left in our case, connects to the display device as well as the slave pedal and does the lion's share of the work.

    For BLE (Bluetooth Low Energy or Bluetooth Smart) each pedal is paired individually to the display device and it is up to the display to combine the two power values. If a display device does not have the ability to pair to two individual power sensors (most do not) a user will see ½ power. Unless that display device has some built in smarts to double the value when only one pedal based power meter is connected.
  • chatlow
    chatlow Posts: 850
    Thanks all. Figured the same regarding BLE and ant+ so decided to rescan with my watch and it found the ant+ id this time, so added this instead and performed crank length and calibration.

    All looks good

    Thanks

Categories