Heart rate via Android App + JetBlack Volt


I’m a new subscriber to XERT and and have an issue with the heart rate reporting via the Android EBC App. Any time I connect my JetBlack Volt trainer to the App, the heart rate reported by my heart rate sensor (cheap XOSS one) as shown in the app is divided by two.

The only explanation for this I can think of is that the app averages between all known heart rate values over some time window. The correct hr value briefly flickers up in the app from time to time, sometimes it says zero, but must of the time it says half of the actual value. The Volt can bridge heart rate data via bluetooth as a special feature, but as I do not use this it likely always reports zero. Also, the Xert app does not allow me to select the Volt as hr source to use the bridging. Neither Zwift, the trainerroad app or my wahoo does have a problem with the Xoss sensor.

Hello Tim, and welcome to the forum

I am also a Jetblack Volt user. This happened to me just once at the beginning. Jetblack have just released a new firmware and a new app for the Volt. It is working great for me.

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Thanks for the hint! It works fine with the new firmware. Also, the new dual bluetooth feature is great for connecting both Zwift and the Xert app to the trainer via Bluetooth.

I am trying the dual bluetooth with Xert but it does not work for me. When I connect the power meter to Xert EBC (not the control) I lose the power control from RGT. But I can see the Power readings in both apps. I will use ANT+ for the Xert EBC. Looks like the tested with Zwift but not RGT. I will contact the

Afaik you can pair both apps as control. The Volt only takes the control commands from the App that was first connected.
I tested it yesterday with a workout controlled by the Xert app and the tour of watopia stage, worked great. I also tried the 10hz reporting feature in resistance mode and that seems to work fine too. Hopefully they’ll get the auto calibration right next time.