PaceOS – user manual

This manual is taken straight from the code (app/app.c, ui/paceui.c, platform/linux/main.c). Texts on the watch are quoted as the watch shows them in English; the language is switched in Menu → System.

Controls at a glance

The watch has one button and a touch screen.

• Press: a short push of the button.
• Hold: keep the button down for about 0.8 s. The watch reacts while you still hold it; you can let go right after.
• Double press: two presses in quick succession (within 0.35 s). Only during a run, where it marks a lap.
• Tap: on a list row or an on-screen button.
• Dragging a finger up and down scrolls lists. Rows narrow towards the top and bottom edge of the round screen.

The screen lights up for 5 s after a press or a touch and with every notice. The backlight mode (auto, always on, off) is set in PaceOS Connect. Menus and lists you leave untouched go back to the clock face after 30 s.

Clock face

The watch has four faces. Each has slots for the data you choose:

• Digital – the big time, one line above it, one under it and two fields at the bottom (default: battery, date, weather, sunrise / sunset). The ring around the edge shows the steps towards 10,000 when the watch counts them.
• Analog – hands (no seconds hand: the watch sleeps between minutes), one field at the top, right and bottom (default: weather, date, battery).
• Runner – the time and four data fields (default: recovery, week distance, training status, VO2max). The ring around the edge shows how much of last week's distance you have run this week.
• High contrast – huge hour and minute digits, one above the other, for sunlight and weaker eyes, a line at the top and the bottom (default: date, battery).

The data to choose from: date, battery (% and the days left at the measured drain), steps, the phone's weather, sunrise / sunset, light left (until the sunset), next alarm, notifications, recovery (hours), week distance (this and last week, Monday on), VO2max, training status, the phone link, heart rate and the training load (7 days, with its load ratio band). The watch computes sunrise and sunset itself (NOAA's algorithm) from the last GPS position and the date. What the watch does not know shows as --: steps while the watch does not count them, sunrise before the first run with GPS (unless you set Home, latitude and longitude, in PaceOS Connect), battery days until the drain is measured (about 15 minutes off the charger), recovery, load and weeks until a run is saved. Heart rate shows only a reading of the last 10 minutes (after a run, say): on the face the optical sensor is off to save the battery. Only the phone has the weather: without it (or when it is older than 3 hours) its slot stays empty.

All faces show icons for the phone (Gadgetbridge), Bluetooth (headphones, for example), an alarm, the timer and the stopwatch. An envelope with a number counts the phone's unread notifications; tap it to open them.

Choosing a face: keep a finger on the face for about 0.7 s. The arrows or a swipe left / right go through the faces, ✓ uses one, the sliders open its settings: tap a slot and pick what it shows (something already in another slot swaps places with it), Colour steps through the accent colours. A press goes back (from the picker to the face, unchanged), a hold to the face. PaceOS Connect has the same in its Watch face group.

When nothing happens on the clock face, the watch sleeps between minutes. On the charger (USB) it does not.

Menu

Hold the button on the clock face. The menu rows:

• Run – prepare a run; below it is the chosen workout, or "free run".
• Workouts – plans and today's suggestion, see Workouts; with no plans the line below says "plans via Connect".
• Routes – GPX courses, see Navigation.
• Phone – notifications and find my phone, see Phone.
• Music – the player, see Music.
• Games – see Games.
• Bluetooth and Wi-Fi – see Bluetooth and Wi-Fi.
• Sync now – uploads runs to Strava and intervals.icu.
• PaceOS Connect – the addresses for setting up the watch from a computer or phone.
• System – language, sync on charge, updates, information about the watch and reset, see System.
• Power – power off and restart.

Running

Getting ready: the GPS screen

Press the button on the clock face (or Menu → Run). The screen shows the activity (or the workout's name), the satellites and the state:

• "searching..." – the watch is looking for its position. Until it has one it shows the satellites in view ("22 in view", GPS and GLONASS together) and the yellow arc grows as their signals get stronger. At about 90 % (four satellites heard well) the fix is usually close; the arc does not go back when the signal wavers. With a fix it shows the number of satellites used;
• "GPS ready, press to start" – the position is accurate enough (within 15 m); the arc turns green and the watch vibrates once.

Press to start the run (a long vibration). You can also start before the GPS is ready. Hold to cancel. If the run does not start within 5 minutes, the watch goes back to the clock face and switches the GPS off.

If a workout from intervals.icu (or a coach suggestion) is planned for today and you have a free run chosen, the watch reminds you once a day ("PLANNED TODAY", "SUGGESTED TODAY").

Activity profiles

Tap the activity's name on the GPS screen and choose:

• Run – outdoors, with GPS;
• Trail – with GPS, for terrain;
• Treadmill – no GPS; the distance is steps times stride length. The watch learns the stride on outdoor runs longer than 1 km;
• Walk – with GPS and an auto pause set for walking.

A press takes you back to the GPS screen. The watch remembers the profile. Each profile has its own data pages and the right sport type in the FIT file. Treadmill runs set no records (the distance is only an estimate).

During a run

• Press – the next data page (round and round). The music page shows only with headphones connected. In a workout step that ends with a press, the press ends the step.
• Double press – a lap: written to the FIT file and announced like an auto lap. The double press can be switched off in the settings (lap key); the watch then acts on a press without waiting for a second one.
• Hold – pause and the stop menu, from any page (also during an auto pause).

Touch lock: while running, the data pages and the map ignore touch – neither rain nor a sleeve presses anything or lights the screen. The music page and the stop menu still take touch.

What the watch announces during a run (with a vibration):

• LAP n – the lap's pace and average heart rate (in a workout the steps announce themselves instead);
• GPS LOST – distance comes from the cadence for now; GPS OK – the track is reconciled;
• ZONE 5 – "HR … – ease off?";
• pace, heart-rate and drink alerts (see below), navigation and phone notifications.

Data pages

The default pages:

1. run: time, pace, distance, heart rate;
2. lap: lap time, lap pace, average pace, lap distance;
3. map: your track (and the course, if you follow one), north up;
4. music (only with headphones).

The treadmill has no map. In PaceOS Connect you set up to 6 pages of 1–4 fields for each profile; the first field is the big one on top. Fields: timer, elapsed time, distance, current, average, lap and last-lap pace, lap time and distance, heart rate, zone, average heart rate, cadence, time of day, battery, the workout, pacer or navigation line, and the elevation of a GPX course. The map and music pages can go anywhere in the list. Distances and paces are in km or miles as set. The watch shows no calories: without the runner's weight they cannot be computed honestly.

Auto lap and auto pause

• Auto lap – every 1 km by default; 100 to 10,000 m in the settings, or off. In a structured workout each step is a lap.
• Auto pause – the run stops when you move slower than about 4.3 km/h for 3 s and starts again when you run faster than about 5.8 km/h for 2 s (walking: 1.8 and 3.2 km/h). It can be switched off in the settings.

Pause and the stop menu

Hold the button to pause ("PAUSED – press: resume hold: finish"). Four round buttons appear at the bottom, from the left:

1. resume (green),
2. save (blue),
3. back to start (orange, a house) – see Back to Start,
4. discard (red, a bin).

With the button: press = resume, hold = save. Resuming takes you back to the page where you paused. "Discard" asks first ("Discard the run?" – Discard / Back): a discarded run is neither saved nor uploaded. A run left paused for 30 minutes is saved by itself ("RUN SAVED – paused for 30 min").

Alerts (free runs)

They are set in PaceOS Connect and apply only to free runs (a workout has its own targets):

• Pace range – after 15 s outside the range "TOO FAST" (a double vibration) or "TOO SLOW" (a long one), again every minute; a short vibration when you are back in range.
• Heart-rate ceiling – after 10 s above it, again every minute.
• Reminder "drink something" every N minutes of running (5–120).

Notifications during a run

What shows during a run follows a setting: calls and texts (default), all, calls only, none. The watch counts the rest and tells you after the run: "NOTIFICATIONS – n during the run". During quiet hours (22–7, for example) notifications and calls neither vibrate nor light the screen; the exception is notifications during a run that the running policy lets through.

Finishing: the summary

After saving, the summary shows distance, time, pace, average heart rate, the number of laps and "run.fit written".

• Press – the Training page.
• Hold – the clock face.

When the watch starts uploading the run, it switches to the sync screen after 5 s. The summary and Training pages go back to the clock face after 2 minutes without a touch. A beaten record is announced ("NEW RECORD"). For 2 minutes after the end the watch measures how fast your heart rate drops – best while standing still.

The run is written as it goes (to storage every 30 s). If the watch crashes or the battery dies, the run is repaired and saved at the next start; you lose at most the last 30 seconds.

The Training page

Estimates from published methods, not measurements. The rows:

• the run's Load and the recovery time in hours;
• Max HR N? – when you held a heart rate above the set maximum for 30 s. Tap to save it and the zones follow. The watch never takes it by itself (a wrist sensor sometimes locks onto the cadence);
• Zones, min – minutes in zones 1 to 5 (by % of max HR, or by heart-rate reserve when a resting HR is set);
• HR drop 1 and 2 minutes after the end ("measuring, stand" while it measures);
• VO2max – today's and overall; computed from steady stretches only, the overall value smoothed over runs;
• 1 km, 5 km, 10 km, half marathon, marathon – the best time in this run and the record;
• Condition – today's form against your VO2max;
• Training status (for example productive, maintaining, peaking, overreaching, detraining) and whether fitness is rising, steady or falling;
• Load ratio 7/42 days (low, optimal, high, very high); until there is enough history, "n of 14 days";
• Prediction for 5 and 10 km.

Press opens the sync screen (while a sync runs), otherwise the clock face.

Workouts

Menu → Workouts. The rows:

1. Free run – with a lap every set distance;
2. today's suggestion from the coach (its name and length in minutes), or "Suggested: rest";
3. workouts planned on intervals.icu with their day ("planned today", "tomorrow", "Thu 17.10.") and your own workouts uploaded through PaceOS Connect.

Tap to choose a workout; the watch goes to the GPS screen. The chosen workout stays until you choose another one or the free run.

During a run with a workout:

• at the start of each step the watch shows its name and description and vibrates;
• the run page shows the step, what is left of it (metres, time, or "press") and the target pace; the pace is coloured against the target;
• outside the target pace "TOO SLOW" / "TOO FAST" with a vibration, a short vibration when back in range;
• a step that ends with a press is ended by pressing the button;
• at the end "WORKOUT DONE – hold to finish the run".

Each step is its own lap in the FIT file, pointing at its workout step.

Coach

• Today's suggestion – the second row in Workouts. One of: rest, recovery, easy, long run, tempo, threshold, VO2max intervals, strides; with a reason and paces. It follows your run history, recovery and load ratio (at most 1–2 hard sessions a week, no two key days in a row, a long run once a week, a taper before a race). In PaceOS Connect you set the runs per week, the long-run day and a race (date and distance).
• Virtual pacer – in the settings, a pace or a target time for a distance, and an even or negative split. During the run the line shows "PACER +0:12" (ahead, green) or behind (red, more than 5 s), what to run now ("run 5:10 /km"), "target reached" or "target out of reach". It applies from the next run and only to free runs. While you follow a course, navigation shows instead of the pacer.
• Condition – once between minutes 6 and 20 of a run: "CONDITION +n vs your VO2max".
• Cadence metronome – a short vibration on the beat (120–230 steps per minute, every 1st, 2nd or 4th step), only while the run's timer runs.

Navigation

Courses

Upload GPX files in PaceOS Connect (Routes). The watch reads GPX from Mapy.cz, Strava, Garmin Connect, Komoot and gpx.studio. In Menu → Routes tap a course (or "No route"); the watch shows its name, length and whether it is a loop, and goes to the GPS screen. If the GPX cannot be read: "cannot read this GPX". You can also choose a course during a run; the watch then follows it from where you are.

During the run the navigation line shows:

• "TO COURSE n m" before you reach the course;
• "LEFT 80 m", "RIGHT …", "TURN BACK …" ahead of a turn;
• "OFF 45 m" in red when you are off course;
• "ON COURSE", at the end "FINISH";
• how much is left to go.

Announcements: a turn about 50 m ahead (a double vibration) and at the turn ("now"), "OFF COURSE" after more than 40 m off the course for 10 s, "ON COURSE" when back, and "COURSE DONE". The map draws the course in blue under your track.

Back to Start

The orange button with a house in the stop menu. The run goes on and the watch guides you:

• along your own track ("along your track, n km"), with the same turn prompts; at the end "AT THE START";
• in a straight line when there is no track yet: "START right / left / ahead / behind" and the distance;
• "no position yet" when the watch does not know the start yet.

Limits: the watch has no base map and no compass. Turns come from the course's shape and the direction only works while you are moving.

Music

• Upload MP3s through PaceOS Connect (Music). Menu → Music shows the song and the number of songs.
• Controls by tap: previous, play/pause, next. During a run, music is one of the data pages (only with headphones connected).
• The Pace has no speaker. Without headphones the watch says "NO HEADPHONES – pair them in Bluetooth", without songs "NO MUSIC". When the headphones disconnect, the music stops.
• When music plays on the phone (through Gadgetbridge), the page shows the phone's song and controls it.

Playing to Bluetooth headphones on the real watch comes with the hardware bring-up.

Phone

The phone is an Android phone with Gadgetbridge (it sees the watch as a Bangle.js). Menu → Phone:

• Notifications – the last 20, newest first; a dot marks the unread ones. Tap one to read it whole (drag to scroll). Dismiss closes it on the phone too; Reply offers the quick replies (set them in PaceOS Connect; without any, the watch offers OK, Yes, No, "Running, call you later", "On my way") and is there only when the app on the phone takes a reply. A notification closed on the phone disappears from the watch. Clear all at the end of the list needs a second tap and closes them on the phone too. Calls nobody took are listed as missed calls.
• Find my phone – the phone rings until you stop it on the watch (the button or a tap), for a minute at most.
• Gadgetbridge – whether the phone is connected.

Calls get their own page with the caller: red rejects, green accepts (you talk on the phone or its headset – the Pace has no microphone), the middle one mutes the watch and the phone's ringer. The button rejects; once muted it only hides the page. During a run the call page shows over the run page, and the button does nothing else to the run. The policy in Notifications during a run and quiet hours apply.

The notifications are kept in the watch's memory only: never written to its storage or its log; a restart clears them. PaceOS Connect also sets whether pop-ups show the message text (otherwise only who sent it) and the phone alert (a vibration when the phone has been disconnected for 30 s).

Bluetooth

Menu → Bluetooth:

• the first row switches Bluetooth on and off (on by default – Gadgetbridge needs it);
• Search – looks for devices for 15 s ("keep the device close");
• the device list, paired ones first: tap a device to pair, connect or disconnect it.

The watch uses connected headphones for music. When a device cannot be connected, the watch says so with a double vibration.

Wi-Fi

Menu → Wi-Fi. Wi-Fi is off by default to save the battery.

• The first row switches it on and off; Search looks for networks.
• Networks are sorted by signal (the connected one first), with a lock on secured ones.
• Tapping a saved or open network connects. For a new secured network a keyboard for the password appears: ABC capitals, 1# digits and symbols, the arrow deletes, ✓ confirms. A press of the button goes back to the list without connecting.
• Tapping the connected network shows its IP address.
• A wrong password: "wrong password or out of range". The password is saved only once the network accepts it.

The watch supports WPA2 and open networks; WPA3-only networks are not listed (the chip's driver cannot do WPA3). Networks can also be added in PaceOS Connect. After connecting, the watch sets its clock and, at most once every 6 hours, looks for an update.

Sync (Strava, intervals.icu)

Set up the accounts in PaceOS Connect (Accounts); the steps are in the FAQ on the website. Then:

• after a run is saved, the watch uploads it by itself when it is connected to Wi-Fi;
• Menu → Sync now uploads everything not uploaded yet ("set it up in PaceOS Connect" when no account is set up);
• the sync screen shows the steps: connecting, Strava, intervals.icu, and the progress. A press goes back to the clock face; the upload carries on.

Each run is uploaded once. The workouts planned on intervals.icu for the next 8 days are fetched at the same time.

Sync on charge

On by default; switch it off in Menu → System → Sync on charge (or in the PaceOS Connect settings). On the charger, 30 s after it is connected and with a sync account set:

• if a saved Wi-Fi network is around, the watch switches Wi-Fi on itself, uploads the runs not uploaded yet, fetches the planned workouts (intervals.icu) and looks for a system update (at most every 6 hours, as before);
• when the watch leaves the charger, Wi-Fi goes off again if it was switched on for this (a sync under way finishes first);
• if no known network joins within 2 minutes, or the sync fails, it tries again after 5 min, then 10, 20 ... at most every 2 hours (also across replugging - a cradle with poor contacts does not cause a sync a minute);
• after a success: again after 6 hours on the charger, or on the next charge (at least 15 min later);
• never during a run.

The charger keeps the watch awake anyway (USB network); unplugged, nothing of this keeps it awake.

PaceOS Connect

Menu → PaceOS Connect shows how to connect to the watch from a browser:

• Wi-Fi – the address IP/connect while the watch is on Wi-Fi;
• USB cable – 172.16.42.1/connect;
• Bluetooth (Chrome, Edge) – the page paceos.lukaskovar.com. Tap to open pairing for 2 minutes ("Pairing open, n s", "choose …" – the watch's name in the browser's list). The watch then shows a code ("Code: 123 456") – type it in the browser. Paired browsers do not need the code next time; the row Forget paired browsers removes them.

Over Wi-Fi, and for pairing, Connect is reachable only while this screen is open on the watch ("open while this page shows"). Without a touch it stays open for 10 minutes.

Workouts and routes go to the watch over Bluetooth too (not only USB); music too, just slower.

Everything else is set in PaceOS Connect: the watch's settings and data pages, Wi-Fi networks, the Strava and intervals.icu accounts, workouts (with an editor), courses, music, run downloads (FIT), updates, the clock and time zone. Which browsers work is in the FAQ on the website.

New:

• Settings - a Sync on charge toggle and a Settings backup card. It downloads a JSON file with all the watch's settings. It holds no secrets: no Wi-Fi passwords, no account tokens (Wi-Fi networks and accounts are not in it). To restore, pick the file; the page asks the watch to check it and shows what would change (and what it skips as invalid or unknown) before anything is applied.
• System - a Support bundle button (over USB or Wi-Fi; over Bluetooth the page explains it needs USB or Wi-Fi, because the bundle is too big) and a Reset card with two actions, see Reset.
• The watch card shows free space, the number of runs and how many are not uploaded yet.

Installing over USB (PaceOS Flasher)

Open https://paceos.lukaskovar.com/flash/ in Chrome or Edge on a computer (Firefox and Safari have no WebUSB) and put the watch in its cradle. Nothing is installed on the computer.

1. Connect – pick the mode the watch is in: stock Android (USB debugging on; confirm "Allow USB debugging" on the watch the first time), fastboot (the bootloader) or the Ingenic USB boot mode, where the page only reads which chip answers. "Restart into fastboot" gets you from Android to fastboot; the page connects the watch again by itself, or asks you once to choose it.
2. Report – what the watch and its bootloader say about themselves. unlocked and secure are shown large: a locked bootloader (unlocked: no) refuses everything below, and no tool can get past that. Download the report (JSON or text) to attach it to a question; it contains the watch's serial numbers and is not sent anywhere.
3. Start PaceOS live – in memory only, nothing is written; a restart brings back the stock system. Choose a signed PaceOS image (.paceimg); an image you built yourself needs an extra tick.
4. Backup – the whole memory of the watch is copied into a folder you choose, and every file is checked against the SHA-256 the watch computes. Keep it, and a second copy elsewhere.
5. Install / restore – stays locked until a verified backup of this watch is loaded (the one you just made, or an earlier one: choose paceos-backup.json and its files, "Verify backup"). Only the boot or recovery partition is written, and only a signed PaceOS image or a partition from your backup. Tick the confirmation each time.

If the page says it cannot open the watch:

• Linux – add the udev rules shown in the page's help (or tools/flasher.sh udev), stop a running adb (adb kill-server), eject the watch in the file manager (gvfs MTP), stop fwupd while in fastboot; a Chrome installed as Flatpak or Snap often cannot use USB at all.
• Windows – install the WinUSB driver for each mode of the watch (Google USB Driver, or Zadig).
• macOS – no driver; close other programs that use the watch.

Keep the tab in front and the computer awake while it transfers. "Save log" stores what happened, without secrets, for a bug report.

System updates

After a sync or when it connects to Wi-Fi, at most once every 6 hours, the watch looks for a new version (channel stable, beta or off in the settings). If there is one, it says "UPDATE – PaceOS x: Menu > System", and the System row in the menu shows "update x".

In Menu → System:

1. tap Update – PaceOS x - tap: install. It works only when you are not running ("after the run") and with at least 50 % battery or on the charger ("charge to 50 % first");
2. the watch shows "downloading n %" and "installing n %";
3. "installed - tap: restart" (and "UPDATE READY") – tap to restart into the new version;
4. "failed - tap: again" – try again.

The new version is written to the other partition. If it does not come up after the restart or fails its check, the watch goes back to the previous version by itself. The watch never accepts an older version. Updates can also be uploaded or downloaded in PaceOS Connect (System).

System

Menu → System:

• Language – tap to switch between Czech and English;
• Update – only when there is one (see above);
• Sync on charge – tap to switch on and off. The line below says "Off", "On, no account yet", after a failure "On, again in N min", otherwise "On: charger + Wi-Fi" (see Sync);
• PaceOS – the system version;
• Boot – how many seconds after power-on the clock face appeared;
• Asleep – the share of time asleep since the start;
• Storage – free space ("N MB free", with ", low" when it is low), see Storage;
• Battery – the charge and, after the charger is unplugged, the measured drain and an estimated battery life ("measuring drain" until there is a measurement);
• Kernel – the Linux kernel version;
• Reset settings - "runs and accounts stay";
• Delete everything (red) - "back to factory state".

The last two are described below.

Reset

Two choices, like Garmin's "Reset Default Settings" and "Delete All Data and Reset Settings". Both are in Menu → System, and neither works during a run or while an update is being written.

Each opens a question page, "Reset settings?" or "Delete everything?":

• a red row Reset settings / Delete everything - "tap, then hold the button", after the tap "now hold the button" (valid for 10 s);
• Cancel - "nothing changes";
• an info row: for settings "Keeps runs, history, music, accounts, Wi-Fi", for delete "Deletes runs, history, accounts, Wi-Fi, pairing".

To confirm, tap the red row and then hold the button. A hold without the tap goes to the clock face (as on every list) and changes nothing; a press goes back; unanswered for a minute, the question is cancelled. After a cancel: "cancelled, nothing changed".

Reset settings. Every watch setting goes back to the defaults, including alarms, data pages, the chosen workout and route, sync on charge and the update channel. Everything else stays: runs, training history and records, workouts, routes, music, the Strava and intervals.icu accounts, Wi-Fi networks, Bluetooth pairings (paired browsers), the time zone, the watch's language (so you can still read it) and what the watch learned (stride length). It is done at once: "SETTINGS RESET" - "runs and accounts kept".

Delete everything. The factory state. Deleted: runs, training history and records, workouts, routes, music, settings, alarms, accounts (tokens), Wi-Fi networks, paired browsers and the Bluetooth address, game records, logs and the time zone. Kept: the system itself and its update state (A/B slots, which slot is current), and the Bluetooth chip's firmware patch (/data/firmware, bt.conf - hardware support). The watch shows "deleting everything", restarts, and finishes the deletion at the start, before anything else uses the data. A power cut in the middle is safe: the next start carries on. Then the watch starts like new (Czech language, default settings).

Over PaceOS Connect

Connect (System page) can only ask. The watch shows the same question with an extra row "Asked by PaceOS Connect" and vibrates. Only someone holding the watch can confirm it (tap + hold). The page shows the state: waiting for the watch, cancelled, refused (a run or an update), done, restarting. Over Wi-Fi the Connect page must be open on the watch, as always.

Games

Menu → Games: Flappy, Dino, Stack, 2048, Snake, Breakout and Simon, each with its best score. Tap to start.

• Press is the game's button, hold takes you back to the games list.
• Flappy, Dino, Stack: the button or a tap.
• 2048: swipes.
• Snake: tap the left or right half of the screen to turn.
• Breakout: drag the paddle with your finger.
• Simon: the four quarters of the screen.

The screen stays lit while you play. A game left on its start or game-over screen goes back to the list after a minute.

Clock (alarms, timer, stopwatch)

Coming. This part of the manual will be added once the alarms, the timer and the stopwatch are done.

Power and battery

• Menu → Power: Power off ("hold to switch on") and Restart. A run in progress is saved before powering off.
• Switching on: hold the button. How long on the real watch will be confirmed in the first test.
• Low battery: at 15 % "BATTERY LOW – charge soon" (during a run "the run is saved if it runs out") with a double vibration. At 3 % the watch saves the run and powers off.
• Charging: the watch says "CHARGING". On the charger it can sync by itself, see Sync on charge.

Storage

A run never fails to record because the watch is full. The watch keeps room for 40 hours of recording plus some for logs (about 7.5 MB; a run file grows by about 83 KB per hour). It is checked when the GPS screen opens and every 10 minutes of a run. When there is less:

• the oldest runs that are already uploaded (to every account that is set) are deleted from the watch, with "STORAGE" - "removed N old uploaded runs";
• runs not uploaded are never deleted. Instead "STORAGE LOW" - "N MB free - upload or delete runs" with a double vibration (once, not repeatedly).

Free space is shown in Menu → System and in PaceOS Connect (the watch card: free, number of runs, not uploaded yet). Connect uploads (music, updates) always leave 10 MB free.

Settings

All settings are in PaceOS Connect and the watch applies them at once (the pacer and the metronome from the next run): language, maximum and resting heart rate, sex (for the training load), auto lap and auto pause, units km/mi, the double press for laps, backlight, profile, the watch face (its data and colour), data pages, alerts (pace, heart rate, reminder), notifications during a run, quiet hours, message previews, the phone alert, quick replies, stride length, the coach (runs per week, long-run day, race), the pacer and its split, the metronome, the update channel and sync on charge. The settings backup is in Connect (it holds no secrets); going back to the defaults is described in Reset.

Troubleshooting

• Connect does not connect over Wi-Fi. The screen Menu → PaceOS Connect must be open on the watch, and the watch must be on the same network as the computer.
• The page paceos.lukaskovar.com does not see the watch over the cable. An https page may not talk to the watch's http address; use the watch's own page http://172.16.42.1/connect/ (the website links to it).
• Bluetooth does not work in the browser. You need Chrome or Edge (on Linux with the flag enabled); iOS, Firefox and Safari have no Web Bluetooth. On the watch, open pairing by tapping the Bluetooth row.
• Wi-Fi does not connect. Check the password. The watch cannot do WPA3-only, EAP (enterprise) or WEP networks.
• Sync uploads nothing. The watch must be on Wi-Fi with internet access and the accounts must be set up in Connect. For Strava the refresh token needs the activity:write scope.
• The watch deleted old runs. It ran low on space and deleted only runs that were already uploaded. Runs not uploaded are never deleted, see Storage.
• "STORAGE LOW". Upload the runs (Menu → Sync now) or delete them in PaceOS Connect.
• Nothing syncs on the charger. An account must be set, Sync on charge must be on and a saved Wi-Fi network must be around. After a failure the watch tries again after 5 min, then 10, 20 ... (Menu → System shows "On, again in N min").
• An update does not start. Finish the run and charge the watch to at least 50 % (or put it on the charger).
• No music. Connect Bluetooth headphones and upload MP3s.
• Touch does nothing during a run. That is the touch lock. Use the button; pausing (hold) unlocks touch.
• A run after a crash or a flat battery. The watch repairs and saves it at the next start.

The support bundle

When you need help, connect the watch with the USB cable and open http://172.16.42.1/cgi-bin/support in a browser, or use the Support bundle button in PaceOS Connect (System; over USB or Wi-Fi, not over Bluetooth). A file paceos-support-….tar.gz is downloaded with the system logs, the settings without secrets, the training history, the update state, partitions and battery. It never contains tokens, Wi-Fi passwords, quick-reply texts, a position (neither the home nor the last GPS fix), runs or music, and the logs never hold the text of phone notifications or who called (only their length). You can look inside before you send it.