A small tray app for Linux and Windows that connects to a Bluetooth LE heart-rate monitor, shows connection status in the tray, and writes the current BPM to a text file. Useful as an OBS text source.
Works with any BLE monitor using the standard GATT HR profile (0x180D / 0x2A37): Polar H10, H9, and most other chest straps and optical armbands.
Grab the latest build from releases and extract it.
On Linux:
tar -xzf gotempo-*-linux-amd64.tar.gz
cd gotempo-*-linux-amd64
./install.shThat copies the binary to ~/.local/bin, adds an icon, and puts gotempo in your applications menu. uninstall.sh removes it. You can also skip the installer and run ./gotempo from the extracted folder.
Run it from a terminal rather than double-clicking. The script prints where it installed to and reminds you to have ~/.local/bin on your PATH, and most file managers either refuse to run shell scripts or run them with the output hidden. If you get "Permission denied", your archive tool dropped the executable bit: chmod +x install.sh, then try again.
Config and data live under ~/.config/gotempo and ~/.local/share/gotempo.
On Windows, extract the zip and run gotempo.exe. It holds everything in %LOCALAPPDATA%\gotempo. The zip also contains gotempo-cli.exe, the same app built as a console binary, for the flags in Command line.
See Files & configuration for the full list.
Windows 10 or later. Nothing to install: the tray and the Bluetooth stack are both built in.
On Linux:
- BlueZ (
bluetooth.servicerunning) - A StatusNotifierItem system tray (XFCE, KDE, most modern panels). The app won't start without one. GNOME has no built-in tray; install the AppIndicator and KStatusNotifierItem Support extension to get the tray icon.
notify-send(fromlibnotify), optional. Notifications are skipped if missing.
git clone https://github.com/httpsterio/gotempo
cd gotempo
go build -o gotempo .Requires Go 1.24+. make windows cross-compiles the Windows binaries from Linux; the Windows Bluetooth backend is pure Go, so no Windows toolchain is involved.
For desktop integration (make install), version stamping, and the release process, see CONTRIBUTING.md.
./gotempoWith no config.json, the app starts scanning. Open the tray menu, wait for your monitor to appear (it must be awake and worn to advertise), and click it to connect. The choice is saved, and later launches connect directly.
Pair and trust the strap before relying on it. On Linux that is bluetoothctl (pair, then trust); trusting is what lets BlueZ reconnect on its own, and an untrusted bond is a suspect in past reconnect failures (see Known issues). On Windows, pair it in Settings → Bluetooth & devices, after which the tray lists it whether or not it is advertising, which a scan alone cannot find.
Most straps allow one connection at a time, so disconnect the monitor from your phone or other apps first. Some allow more than one.
| Item | Behaviour |
|---|---|
| Start logging / Stop logging | Begin or stop logging: writes the current BPM to gotempo-bpm.txt and appends each reading to a per-session CSV (see Files & configuration). Greyed out when not applicable. |
| Two-player mode | Follow two straps at once, for a two-player cabinet or for recording two people. Off by default; changes what clicking a device does, see below. |
| Device list | Known devices (most-recently-used first) plus newly scanned ones, listed directly in the menu. Click one to switch; the current device is marked and not clickable. Up to six shown. With two-player mode on, a click instead cycles that strap through P1, P2 and unassigned, and the label shows [P1]/[P2]. |
| Rescan for new devices | Runs a fresh 15-second scan; new monitors appear in the list. On Windows the list also includes monitors already paired in Settings, which a scan cannot see. |
| Open log folder | Opens the log and CSV directory in a file browser. |
| Open config folder | Opens the directory holding config.json. |
| Autostart HR log | When checked, logging starts automatically on launch. |
| Start on boot | Adds or removes ~/.config/autostart/gotempo.desktop. |
| Quit | Exits the app. |
While a player's ITGmania profile is choosing straps, an ITGmania is choosing straps line appears above the device list and the controls the game has taken over grey out: the logging toggle, Autostart HR log, Two-player mode, and every device row. Clicking them would write to config.json and then change nothing, because the profile keeps overriding it. They come back as soon as the game lets go.
gotempo also runs headless, for systems without a tray or for scripts and status bars: connect without the tray (--no-tray), stream readings (--print-bpm), or report the running app's state (--status). Full flag reference, output formats, exit codes, and a systemd unit in docs/CLI.md.
gotempo can follow two heart-rate straps at once, for a two-player ITGmania cabinet or for recording two people together. Tick Two-player mode in the tray, then click a device to cycle it through P1, P2 and unassigned. Headless:
gotempo --two-player --player 2 --select-deviceThe second strap writes its own gotempo-bpm-p2.txt and gotempo/hr-p2.txt, and --status reports both. The first strap's filenames never change, so an existing OBS source or theme module keeps working. Off by default; see Two straps.
On a cabinet, a player can name their own strap in their ITGmania profile and gotempo follows it while they play, with no trip to the tray menu. Add gotempo.ini to their profile folder:
[gotempo]
Device=24:AC:AC:18:41:CCPair the strap to the machine once first. The assignment is never written to config.json, so quitting returns to whatever the tray is set to. See Straps from ITGmania profiles.
gotempo can drive gotempo-sl-module, a Simply Love theme module that draws your heart rate on ITGmania's gameplay screen and over the density graph on the evaluation screen. Install the module, then set one key in config.json to its full path:
"itgmania_module": "/home/you/.itgmania/Themes/Simply Love/Modules/gotempo.lua"Restart gotempo. It writes hr.txt beside the module, and the panel appears in game. The overlay does not depend on the logging toggle.
gotempo --itgmania-module <path> sets the same key. See ITGmania overlay for the file format and where the module lives on each OS.
When the connection drops, gotempo reconnects on its own:
- It retries silently for a short while. A device that returns in this window reconnects with no notification.
- If that fails, it sends one "device lost" notification and keeps retrying until the device returns, then sends "reconnected".
Those notifications are only for straps you configured. A strap that arrived from a player's ITGmania profile stays silent, or a cabinet would spend the evening reporting on people who have gone home.
Reconnection connects straight to your device by address, it does not scan, so it never probes other Bluetooth devices in range while waiting for your strap to come back. Scanning happens only when you pick a device or hit Rescan. Connecting by address needs the device to be known to BlueZ already, which it is once you have paired or connected it once.
The BPM file keeps its last value across a brief drop and clears after about ten seconds disconnected, so it doesn't leave a stale reading (see Files & configuration).
It also survives the Bluetooth adapter being toggled off and on, including when it returns on a different hciN index.
- Command line: headless mode, all flags, output formats, exit codes, systemd
- Files & configuration: file locations and formats,
config.jsonschema, ITGmania overlay - CONTRIBUTING.md: build from source, versioning, releases
- Known issues
- macOS support