π FINISH LINE
Point the camera across the line β it auto-times each lane
Meet mode (website)
Each detected (or tapped) crossing posts to the website automatically (marked app-timed). If WiFi drops, times queue on this phone and retry every few seconds β nothing is lost.
Live β align the red line with the finish line
Motion at the line (live). With Auto on, the white firing mark rides just above the scene's own noise β it rises at dusk (grainier sensor) and drops in daylight, by itself. Have someone walk across: the bar should jump past the mark (turns green). Auto off = you place the mark with the slider.
π Camera setup β how to position the phone
- Tripod at the finish line, off to the side, aimed straight down the line (perpendicular to the runners) so the painted finish line runs vertically in the view β then drag the red line onto it.
- Back up until all lanes fit top-to-bottom in the frame β usually ~5β10 m to the side. Each grey band should sit over one lane (use Flip β if lane 1 is at the wrong end).
- Phone at about torso height so the body β not arms/legs β breaks the line.
- Keep it steady and out of the wind if you can β wedge the tripod or weigh it down.
Cloudy / windy? The timer automatically cancels out overall light shifts (a passing cloud) and gentle shake, and ignores single-frame flickers β so it holds up in most conditions. In rough wind, steady the phone; with Auto threshold on it re-learns the scene's resting level by itself (manual slider does it too, with Auto off). Things blowing across the line (flags, loose clothing) can still trigger a lane β fix those with review below.
Dusk / indoor? Auto threshold rides above the sensor grain as light fades, so false triggers stay rare β but a dim runner also makes a weaker signal. Watch the Light row: at "dim" auto-detect still works (have someone test-walk the line); at "low" trust β Record + review instead, or add light (floodlight, car headlights work great aimed across the line).
Arm auto-timer β each lane times itself as a runner crosses. Tap a lane band to time by hand as a backup. It's a ~camera-frame-rate approximation (~30 ms) β review/correct close calls below.
π Sprint mode β one phone fires the gun
Solo 40-yard-dash style timing, no start phone needed. Put this phone at the finish line (camera across the line, lane armed as usual), walk to the start, tap Start sprint: it calls marksβ¦ setβ¦ then fires a BANG from the speaker after a random hold β the clock starts when the bang reaches you (sound-travel compensated over the picked distance) and stops when you cross the line. Turn the volume up and flip the ring/silent switch OFF silent (iPhone mutes web audio on silent). Sets Lanes to 1.
π‘ Speed gates β two phones, any spacing
Two phones on the same meet code, each aimed across its own line, any distance apart. One tap on each phone does the whole setup — it connects, turns the camera on, and arms the gate. Then align the red line with each gate line, enter the spacing on the FINISH phone, and run: break the START gate (clock starts), break the FINISH gate (speed appears in m/s + mph). The start gate closes for 3 s after each crossing, then re-arms β walk into position BEFORE arming, or wait 3 s after any stray crossing, because every gate-1 crossing starts a fresh run.