A lightweight program to display the heart rate reading from a Bluetooth Low Energy device.
This has only been tested on a Polar H7 (non-referral link) but others should work.
Reportedly working devices include:
Requires Windows 8.1 or newer.
The executable and code are released under MIT license.
Code can be built using Visual Studio Community 2022.
I owned a Polar H7 I could not get to work with any iOS software for use in the gym. I decided to repurpose it as a way to read my heartrate while I worked on the computer. I create my own due to lack of available software.
The program's secondary purpose is for Twitch streamers. After looking into streamer setups I saw an excessive mix of hardware and software was needed. I am not a Twitch streamer but I am willing to add the customizations needed by request.
1.7.4 May 3rd, 2022
1.7.3 February 10th, 2022
1.7.2 August 13th, 2021
1.7.1 December 29th, 2020
1.7 November 30th, 2020
1.6 September 27th, 2020
1.5 June 13th, 2020
1.4 April 27th, 2019 ·
I do not have the time to turn this into production grade software but I am
willing to expand it to your needs. At startup, the program searches for an
appropriate device and attempts to register a notification event for
heart_rate_measurement. If this fails, the error is likely vague and not overly
helpful. If you believe your device should work with this software but does
not, please open a github issue with specifics.
This will not work for any general USB/bluetooth heart rate monitor. It has to
be a Bluetooth Low Energy device supporting heart_rate_measurement.
By default, only an icon in the system tray is displayed. When the heart rate goes over an alert threshold, a balloon notification shows.
Clicking the system tray icon reveals a window with scaling text. This is for Twitch streamers to be able to region for broadcast.
Most settings are exposed in the UI through a context menu by right clicking the main window or the system tray icon. The rest can be accessed by editing the XML settings file directly.
Options not inside the UI
Right clicking the system tray icon gives the option to edit an XML settings
file. When the editor is closed, the settings will be reloaded automatically.
The file is %appdata%\HeartRate\settings.xml
| Setting | Type | Default | Description |
|---|---|---|---|
Sizable |
bool | true | If the window is a normal sizable window. false looks better but is not recognized by OBS as a window. |
LogFormat |
text | csv | The format to write to the LogFile. Only "csv" is valid. |
LogDateFormat |
text | OA | The format to write the date column as. See Datetime formatting. |
LogFile |
text | empty | The full path of where to write the logged data to. If empty, no file log is kept. A %date% token can be included to substitute in the date. A custom formatter can be included, such as %date:MM-dd-yyyy% Example: C:\users\joe\desktop\heartrate-%date%.csv |
IBIFile |
text | empty | The full path of where to write the IBI data to. Writes log of RR-Intervals in milliseconds in IBI supported file format. Supports date syntax like LogFile does. |
HeartRateFile |
text | empty | The full path of where to write the last heart rate to. Anything previously in the file is overwritten. Only the the most present heart rate will exist in the file. Supports date syntax like LogFile does. |
AlertLevel |
number | 65 | The heart rate to display a system tray notification balloon at. 0 to disable. |
WarnLevel |
number | 70 | The heart rate to use WarnColor at. 0 to disable. |
AlertTimeout |
number | 120000 | The amount of milliseconds to cooldown for being able to show an alert after one was shown. |
DisconnectedTimeout |
number | 10000 | The amount of milliseconds after disconnecting to await for a valid device connection before displaying "X" |
UDP |
host:port | empty | A UDP end point to write the "LogFile" output to. Format is ip:port, ie: <UDP>127.0.0.1:2115</UDP> |
Settings also exposed by the UI
| Setting | Type | Default | Description |
|---|---|---|---|
FontName |
text | Arial | The font name for the system tray icon. |
UIFontName |
text | Arial | The font name for the window display. |
UIFontStyle |
text | Regular | The font style for the window. Multiple styles can be specified by comma separation. Regular, Bold, Italic, Underline, Strikeout. |
UITextAlignment |
text | MiddleCenter | The alignment of the text in the UI. Can be TopLeft, TopCenter, TopRight, MiddleLeft, MiddleCenter, MiddleRight, BottomLeft, BottomCenter, BottomRight. |
Color |
color | FFADD8E6 | The default color for the system tray icon. |
WarnColor |
color | FFFF0000 | The system tray icon color once WarnLevel has been met. |
UIColor |
color | FF00008B | The default color for the window display. |
UIWarnColor |
color | FFFF0000 | The window display color once WarnLevel has been met. |
UIBackgroundColor |
color | 00FFFFFF | The background color for the window display. |
UIBackgroundFile |
text | empty | The full path of a background image. |
UIBackgroundLayout |
text | Stretch | The background image display layout. Possible values: None, Tile, Center, Stretch, and Zoom. More information. |
UIFontUseSize |
bool | false | Should the size in UIFontSize or selected from the Font dialog be used. If false, the font size scales automatically with the window. |
UIFontSize |
number | 20 | The size of the font if UIFontUseSize is true. |
UIWindowSizeX/UIWindowSizeY |
number | 350/250 | The saved window size. This is automatically saved when resizing. |
color values are formatted as 32bit ARGB hex values. Leading 0's are optional.
Datetime formatting is done using the standard C# syntax. One special exception is "OA" which will convert to an "OLE Automation Date" formatted date, which is useful for Excel.
The default LogFile date formatter is yyyy-MM-dd hh-mm tt. The timestamp
is taken at the startup time of the program.
Documents about standard and custom datetime formatters: https://docs.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings https://docs.microsoft.com/en-us/dotnet/standard/base-types/standard-date-and-time-format-strings
Some builds of Windows 10 have bug related to security which causes Desktop apps to stop receiving notification callbacks from GATT characteristics after receiving a few initial callbacks. More details available or in similar posts on social.msdn.microsoft.com.
There are several workarounds, the simplest being creating an AppId for the app in the Windows Registry and adding a security setting for the AppId, like below:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID\{C6BFD646-3DF0-4DE5-B7AF-5FFFACB844A5}]
"AccessPermission"=hex:01,00,04,80,9c,00,00,00,ac,00,00,00,00,00,00,00,14,00,\
00,00,02,00,88,00,06,00,00,00,00,00,14,00,07,00,00,00,01,01,00,00,00,00,00,\
05,0a,00,00,00,00,00,14,00,03,00,00,00,01,01,00,00,00,00,00,05,12,00,00,00,\
00,00,18,00,07,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,20,02,00,00,00,\
00,18,00,03,00,00,00,01,02,00,00,00,00,00,0f,02,00,00,00,01,00,00,00,00,00,\
14,00,03,00,00,00,01,01,00,00,00,00,00,05,13,00,00,00,00,00,14,00,03,00,00,\
00,01,01,00,00,00,00,00,05,14,00,00,00,01,02,00,00,00,00,00,05,20,00,00,00,\
20,02,00,00,01,02,00,00,00,00,00,05,20,00,00,00,20,02,00,00
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\AppID\YOURAPP.exe]
"AppID"="{C6BFD646-3DF0-4DE5-B7AF-5FFFACB844A5}"Wanting to remain lightweight and not having an installer, this is not handled automatically by the program.
Heart icon made by Paomedia.