Ran into an issue with my Polar H7 Chest Strap and Runtastic lately. Got ready for work this morning, put the chest strap on and fired up the Runtastic app on my smartphone. Everything was working fine, GPS signal picked up in seconds and my pulse showed in the display just as alway. So i went on the 15 km ride to work and started wondering why the Runtastic app didn’t announce the changes for the heart rate zone. I stopped, turned on the smartphone display to check the heart rate in the Runtastic app and, to my surprise, it kinda stuck at 79 bpm.
Left wondering, i continued my commute and checked the Polar H7 battery (well, technically i replaced it as i had a spare battery in my backpack). First impression after replacing the battery was “Yay, heart rate now recognized correctly”. That joy lasted for about 10 seconds or so..i turned the display off and back on again to check the heart rate again and noticed that the Runtastic app didn’t show any heart rate at all…weird things going on there.
Rinse and repeat:
* Bluetooth off
* Bluetooth on
* Start Runtastic App
* Connect chest strap via Runtastic setting
* Lock Smartphone
* Unlock Smartphone
* Check Runtastic App for the heart rate
* Notice that the bluetooth connection was dropped
I did that about ten times or so, close to going fucking mental. It worked fine yesterday, why the hassle today? I googled how to reset the Polar H7 and tried all suggestions on that page. Neither one worked for me, the bluetooth connection between the Polar H7 and my smartphone dropped the very second i locked the screen. Erm…i was about to go fucking mental when it struck me that there was an update available for Runtastic in the Google Playstore which i did yesterday evening. Update version was 6.8.1 and to rule out that it is a problem with the Runtastic app in version 6.8.1 i restored an earlier backup of version 6.8.0 via Titanium Backup.
After the restore was complete i rebooted the phone and then fired up Bluetooth and Runtastic, added the Polar H7 chest strap via Runtastic Settings. Heart rate showed up in the display, i locked the phone and crossed my fingers. Unlocking the phone i expected the bluetooth connection to be dropped again but…hip hip hooray, the connection was still working and the heart rate showed up…everything back to like it used to be before the update of Runtastic.
The issue was with Runtastic version 6.8.1 which, for unknown reasons, seems to drop the connection to the chest strap when locking the phone (didn’t check if it also happens when switching apps). Restoring Runtastic version 6.8.0 solved the problem for me and with the old version in place the heart rate was recorded just fine on my way home.