Precision Clock Companion

TIME · PRECISION · STANDBY

HOLDOVER TOLERANCES

1 ms 10 ms 100 ms

TIME SOURCE

FORMATS

⚠ {{modesCapNote}}

Tick the modes to enable; the buttons cycle through them. ON FACE

{{modeEnabledCount}} ENABLED

DATE ROW

WEEKDAY

TIME ROW

ASTRO DATE ROW · SUN / MOON / GRID · TIME ROW KEEPS TICKING

MODE

PAGE DWELL

MS · SUN & LAT/LON SUB-SCREENS PAGE AT THIS RATE (MIN 250)

FACE

BRIGHTNESS {{brightPctLabel}}

DAC CURVE γ {{gammaLabel}}

MASTER DAC — PERCEPTUAL LAW

COLON STYLE

LED BALANCE

Per-segment{{balSeg}}

Colon{{balColon}}

CURRENT-SHARING COMPENSATION · OFF / AUTO / MANUAL STRENGTH · SET VIA config.txt OR MENU

POINT VALUES · DAC CURVE {{dacApplyNote}}

DRAG A POINT · X = SENSOR ADC 0–4095 · Y = DAC BRIGHTNESS 0–4095

PTADCDAC

PRESETS

config.txt — DEVICE USB VOLUME {{cfgName}}

UNSAVED CHANGES

AS SET IN MENU — ON-DEVICE EDITS (SETTINGS.BIN)

Writes these values into the editor below as key = value lines. SAVE TO CLOCK then makes config.txt the source of truth for them.

Serial config is write-only. Read config.txt and SETTINGS.BIN (the on-device menu-edit store) via the CLOCK drive (Chromium only). Write-back is off by default; re-plug or reboot the clock to reload it.

EMULATOR config.txt — LIVE via the firmware's own parser BETA

APPLY runs each line through the firmware parser and reboots the emulator. IMPORT aligns the emulator to a clock's config.txt. {{emuCfgSync}}

CLOCK SETTINGS LIVE OVER SERIAL

Timezone override ▾

Matrix frequency ▾

Time tolerance ms

Simulated position

RE-ENUMERATES USB · ≈3 S

DIAGNOSTICS

TTFF DEVICE ONLY

Diagnostic modes override the face until cleared.

FIRMWARE & DATA

Emulator firmware{{fwVer}}

Source{{fwSrc}}

Built{{fwBuilt}}

ProvenanceBYTE-FAITHFUL · 4363/4363 VS AN INDEPENDENT REFERENCE · VERIFIED AGAINST A PHYSICAL MK IV ON GPS

Timezone data{{fwTz}}

THE CLOCK FACES RUN clock4 C COMPILED TO WEBASSEMBLY AT BUILD TIME, DRIVEN BY A VIRTUAL GPS. THE UPDATE CHECK COMPARES THE BUILT-IN COMMIT TO THE rollup HEAD ON GITHUB.

PCC BRIDGE · pccd

Installed{{pccdVer}}

THIS pccd RUNS FROM A DEV CHECKOUT (-w). SELF-UPDATE IS DISABLED. UPDATE BY HAND:
{{pccdCmd}}

UPDATE NOW: pccd DOWNLOADS AND VERIFIES THE LATEST RELEASE (SHA-256 + SELF-TEST), SWAPS ITSELF, AND RELAUNCHES. THE APP RECONNECTS.

App{{pccdAppLine}}

REFRESH APP: pccd PULLS THE LATEST WEB APP FROM PAGES (SHA-256 VERIFIED) AND SWAPS IT IN WITHOUT RESTARTING — WEB-ONLY FIXES BETWEEN RELEASES. DAEMON FEATURES STILL COME VIA UPDATE NOW.

STANDBY — NO CLOCK CONNECTED

This is your computer's system time. Connect a Precision Clock Mk IV for live GPS-disciplined data, or run a simulation.

01 · {{faceRoomCap}}

POSE

DATE ROW SOURCE

Send / set below switches the date row to that source.

THE TWO BUTTONS ON THE DATE BOARD EDGE ARE LIVE — SAME CONTROLS. HOLD 1 + 2 TO OPEN THE MENU · TAP 1 / 2 TO MOVE · HOLD 1 + 2 TO SELECT

THESE DRIVE THE BUILT-IN FIRMWARE'S MENU, NOT THE CONNECTED CLOCK'S. ITS OWN MENU IS THE TWO BUTTONS ON ITS DATE BOARD.

HARDWARE CALIBRATION Drag furniture on the board or edit the JSON. Changes apply to the clock live.

{{hwJsonStatus}} x = mm along board · y = mm down the pane

{{hwReadout}}

Significant to

Date row

Brightness

{{rkBrtV}}%

Zone

Grid

Source

OBSERVER — DRIVES SIDEREAL / SOLAR / GRID & THE REAL SKY {{emuObserverTag}}

LAT LON

TIME ZONE

The Mk IV takes its zone from the GPS fix. The emulator follows the browser zone; a bare device with no fix shows UTC.

ACCESSORIES

MARQUEE

PRESET

TARGET {{cdTargetLabel}}

No sources yet. Add a REST feed (JSON path, regex, or first line of text); it polls, and PUSH sends its value to the date row.

Stored in this browser (localStorage); header tokens are saved in the clear. AUTO pushes each new value but does not override countdown or diagnostics.

Not implemented yet.

Link

Session

Fix

Firmware

Config

Transport

01 · CONNECTION WEB SERIAL · PCC BRIDGE

Port{{cPort}}

Device{{cDevice}}

Framing115200 8N1

Session{{cSession}}

Fix{{cFix}}

Satellites used / in view{{cSats}}

Fix age{{cAge}}

CONNECT DEVICE OPENS A REAL MK IV: PCC BRIDGE IF pccd IS RUNNING, ELSE WEB SERIAL (CHROMIUM). SEE "CONNECTING A REAL CLOCK" BELOW. SIMULATE RUNS A LABELLED DEMO; IT PAUSES WHILE A REAL CLOCK IS CONNECTED. READ CLOCK DRIVE READS config.txt FROM THE DEVICE'S USB DRIVE (SERIAL CONFIG IS WRITE-ONLY).

BROWSER SUPPORT LIVE CHECK

Web Serial API{{supSerial}}

PCC bridge (pccd){{supBridge}}

Secure context{{supCtx}}

Engine{{supChrom}}

THIS CONTEXT CANNOT REACH THE CLOCK

Web Serial needs Chromium on https or localhost. The PCC BRIDGE below works in any browser.

CONNECTING A REAL CLOCK TWO TRANSPORTS · PICK ONE

Web serial{{trWsV}}

RequiresCHROMIUM · HTTPS OR LOCALHOST

InstallsNOTHING

OpensPORT PICKER · ONE TAB

PCC bridge{{trBrV}}

RequiresANY BROWSER

ServesTHIS APP AT :4192

Also feedsCHRONY · STRATUM-1 NTP

Install pccd RELEASES

Run pccd, then open the address it prints and click CONNECT DEVICE. Served over https, Safari and Firefox cannot reach a local bridge — use the localhost copy.

SIMULATION DRILL SIMULATION ONLY

Drop GPS and run time-lapse to watch holdover grow. With fade on, sub-second digits dim as the 3-sigma bound passes their place value.

Satellites

HDOP

Grid

Fix age

Sky coverage

Recorded

{{sPasses}}passes

03 · SKY PLOT N UP · RINGS 30°/60° · SIZE = C/N₀

LAYERS

TRAIL

GPS FIX {{fFix}}

Latitude{{fLat}}

Longitude{{fLon}}

Altitude{{fAlt}}

HDOP{{fHdop}}

Satellites used / in view{{fSatsUV}}

Maidenhead grid{{fGrid}}

CELESTIAL OBSERVER FRAME

Sun alt / az{{cSunAlt}} / {{cSunAz}}

Moon alt / az{{cMoonAlt}} / {{cMoonAz}}

Moon phase{{cMoonPhase}} · {{cMoonIllum}}

Sunrise{{cRise}}

Sunset{{cSet}}

NEXT TRANSITS {{starSrc}} · $PMSTAR

SESSION RECORDED PASSES

Started{{sStarted}}

Passes{{sPasses}}

Observations{{sObs}}

Peak elevation{{sPeak}}

Sky coverage{{sCover}}

GPS {{nGps}} GLO {{nGlo}} GAL {{nGal}} BDS {{nBds}}

04 · C/N₀ VS ELEVATION ANTENNA / MULTIPATH QC

GPS GLO GAL BDS

SIGNAL BARS dB-Hz · DIM = UNUSED

C/N₀ OVER TIME — PER PRN TOP 8 BY SIGNAL

CONSTELLATION

WINDOW

05 · STATIC-POSITION SCATTER E/N OFFSET FROM RUNNING MEAN

WINDOW

EACH FIX = ONE SAMPLE · AGE-FADED · SHARED WITH SIGNAL

PRECISION FROM POSITION SCATTER

CEP 50%

2DRMS 95%

σ east / σ north{{pSigE}} / {{pSigN}}

Mean latitude{{pMeanLat}}

Mean longitude{{pMeanLon}}

Fixes in window{{pN}}

Time to first fix{{ttffLabel}}

DOP HISTORY HDOP — · PDOP – – · VDOP · ·

FIX CONTINUITY TYPE BAND + SATS USED

06 · TIMING — PPS HOST-TIMESTAMPING {{ppsBanner}}

Phase jitter RMS

1σ AT THE PPS EDGE

Peak-to-peak

WORST EXCURSION

Osc drift

{{tDrift}}ppm

FREE-RUNNING CRYSTAL

Holdover

{{tHold}}s

Die temp

{{tTemp}}°C

ON-DIE SENSOR

PPS edges

PHASE AT PPS EDGE MEDIAN-CENTRED · ROBUST ±1σ BAND

CAPTURED IN FIRMWARE AT THE PPS EDGE (SYSTICK ≈12.5 ns). USB TRANSPORT JITTER IS EXCLUDED.

OSCILLATOR DRIFT + DIE TEMP CAL WINDOW 63 s → STAIRCASE

ppm = calerr · 10⁶ / (32768 · 63). ONE STEP PER SUCCESSFUL RTC CALIBRATION.

DRIFT VS DIE TEMP {{fitStatus}}

32 kHz TUNING-FORK PARABOLA. FITTED CURVE IN AMBER.

ALLAN DEVIATION — FREE-RUNNING OSCILLATOR σ_y(τ) · OCTAVE TAUS · LOG-LOG

COMPUTED IN FIRMWARE (MODE_ADEV / $PMADEV). HADAMARD IN AMBER WHEN PRESENT; DASHED τ^-½ = WHITE-FM REFERENCE.

TEMP COMPENSATION — FIRMWARE LEARNED MODEL {{fwTcState}}

HSE — system clock{{fwTcHse}}

LSE — battery RTC{{fwTcLse}}

Learned die range{{fwTcRange}}

Read back{{fwTcMeta}}

LEARNED ON-DIE, READ VIA "tc_dump = on" → $PMTXTC. APPLIED DURING HOLDOVER.

TEMP COMPENSATION — SOFTWARE TCXO HOST FIT · CROSS-CHECK OF ON-DIE LEARNING

k0 / k1 / k2 (ref 25 °C){{fitK0}} / {{fitK1}} / {{fitK2}}

Samples{{fitN}}

Temp spread{{fitSpread}}

Fit residual RMS{{fitRms}}

Compensation state{{compState}}

{{compLine}}

NEEDS DRAFT FIRMWARE WITH pps=on ($PMTXTS TIMESTAMP + DIE TEMP). FITS ppm(T) FROM RTC CALIBRATION ERROR AND PRODUCES A tc_* SEED BLOCK FOR config.txt (tc_seed=on GOES LAST). tc_dump ON THE CLOCK IS THE REFERENCE. ABSOLUTE UTC OFFSET IS NOT MEASURABLE OVER USB (≈1 ms), SO JITTER, STABILITY AND DRIFT ARE SHOWN.

07 · SIGNAL PATH — pccd PREFILTER

RAW PPS OFFSETS IN, ONE TRIMMED MEAN OUT PER GROUP. A MAD GATE DROPS OUTLIERS, A TRIMMED MEAN OF {{spGVal}} CUTS SCATTER ~√{{spGVal}}.

RAW → CLEAN RMS

{{spRawRms}} → {{spCleanRms}} µs

REDUCTION

AGGREGATE {{spSqrtG}}

REJECTED

{{spRej}} / {{spTot}}

KEPT

GROUPS OUT

1 PER ~{{spGVal}} s

GATE

{{spGate}} µs

GATE σ ×K{{spKVal}}

TIGHTER DROPS GOOD · LOOSER PASSES OUTLIERS

GATE WINDOW{{spWVal}}

RING FOR MEDIAN + MAD

GROUP SIZE{{spGVal}}

SCATTER ÷ √GROUP

σ FLOOR µs{{spFVal}}

NEVER GATE TIGHTER THAN THIS

corrtimeratio{{spCVal}}

DOWNSTREAM · CHRONY CORRECTION PACING

chrony.conf

{{spConfig}}

ARCHIVE — OFFSET TO GPS TIME

RECORDED BY pccd ON THE BRIDGE HOST (ONE POINT PER PREFILTER GROUP, ~8 s). TOP: OFFSET SENT TO chrony; BAND = MIN/MAX PER BUCKET. BOTTOM: OSC DRIFT (RED, ppm) + DIE TEMP (AMBER).

07 · GROUND TRACK

ORTHOGRAPHIC · DRAG TO ROTATE

WORLD · EQUIRECTANGULAR

PROJECTION

TRAIL

READOUTS LIVE

Sub-solar point{{gSub}}

In view at observer{{gVis}}

Observer grid{{fGrid}}

NOTES

SATELLITES AT SUB-SATELLITE POINTS · TRAILS = GROUND TRACKS · SUN GOLD · MOON COOL · OBSERVER GREEN.
ONE TRAIL CONTROL — SHARED WITH THE SKY PLOT.
{{landNote}}

08 · SKY ARCHIVE DAEMON · AGGREGATE

RANGE

RECORDED BY pccd (ONE SNAPSHOT PER 60 s). C/N0 MEAN (RED), MAX (DASHED), SATS USED (AMBER, RIGHT SCALE). AGGREGATE ONLY — THE RECORDER KEEPS NO PER-SATELLITE TRACK YET.

08 · SKY ARCHIVE

NO RECORDER

The archive reads the pccd bridge daemon's flight log. Connect through pccd to record and browse past sky conditions.

08 · CONDITIONS AT FIX OPEN-METEO · KEYLESS

Temperature{{wTemp}}

Feels like{{wApp}}

Sky{{wCode}} · {{wCloud}}

Humidity{{wRh}}

Pressure MSL{{wMslp}}

Wind / gust{{wWind}} / {{wGust}}

Precipitation{{wPrecip}}

Updated{{wAsOf}}

Point forecast at{{wPos}}

WEATHER UNAVAILABLE

Open-Meteo could not be reached. The clock and GNSS views are unaffected — weather returns when the network does.

PROTOTYPE CONTROL

PUSH TO CLOCK TEXT MODE

REFRESH

Sends as text mode — marquees automatically past 10 characters. The date row carries the message; time keeps ticking.

09 · SERIAL MONITOR — RAW NMEA {{monRate}}

FILTER {{monShown}}

RX TEXT · TX RED · ERR ORANGE

TELEMETRY LOG — PERSISTENT BETA INDEXEDDB · CONNECTED ONLY

Logs position, satellites, temperature and clock skew to this browser for rewind and scrub. Off by default. A simulation is NEVER logged.

{{telStat}} KEEP

REWIND · SCRUB BETA {{rvTime}}

Drag the timeline to scrub. Hatched spans are CLOCK DISCONNECTED (no data recorded).

POSITION

FIX

SATS

TEMPERATURE

CLOCK SKEW

No recorded telemetry yet. Turn on LOG MY CLOCK'S DATA above and connect the clock. Its stream is recorded here.

10 · SESSION IN-MEMORY

Started{{eStarted}}

Duration{{eDur}}

Position fixes{{eFixes}}

Satellite observations{{eObs}}

NMEA lines held{{eLines}}

PPS samples{{ePps}}

SESSION IS HELD IN MEMORY. CLEARED ON RELOAD.

RECORDED DATA DOWNLOADS

POSITION CSV

Fix time series — lat/lon/alt, E/N offsets, DOP, sats, fix type

SESSION JSON

Full session — observer, stats, satellite snapshot, PPS fit

STRUCTURED

TRACK GPX

Fix track for GIS tools — 1 point / 5 s

SATELLITE CSV

Sky history — az/el per satellite (1 pt / 30 s) with nearest C/N₀

RAW NMEA

Received sentences as captured, checksums intact