Sub One

Chapter 1

Before you start

Sub One times a shot string from the wrist. The Apple Watch listens to its accelerometer for the recoil of each shot, so it needs no microphone and sends audio commands via Bluetooth to your enabled hearing protection. The iPhone is where you access your firearms and history.

What you need

• An iPhone with the Sub One app installed.
• An Apple Watch paired to that phone.
  • The watch app installs along with the phone app, which can take several minutes. If it doesn’t automatically install, It appears under Available Apps in the Watch app on the phone.

Who does what

Which watch you have changes one thing

Series 8, SE (2nd generation), Ultra and later sample the accelerometer at 800 Hz. Older watches sample at 100 Hz. The app uses whichever your watch offers and shows the rate on the watch home screen and on every result. You do not set it.

Chapter 2

Send your firearm to the watch

A firearm profile holds the gun’s details and, once calibrated, what it feels like at your wrist. It is created on the phone and used on the watch.

1. On the phone, open the Firearms tab and tap +. Name the gun and fill in what you know. Save.
2. A gun that has not been calibrated shows an orange warning triangle in the list. That is expected.
3. Saving a firearm sends the list to the watch. You can also send it yourself: open the Watch tab and tap Send firearms to watch.
4. Wait for the green Profiles received pill. It appears after the watch has written the list to disk, so it means the guns are really there.
5. On the watch, tap the firearm name on the home screen. Your gun should be in the list, marked not calibrated.

Firearms are added and edited on the phone only. The watch list ends with a reminder of that.

Chapter 3

Calibrate

Calibration teaches the app what this gun feels like on this wrist. It is required before START will work, and it belongs to the pair of this firearm and this watch.

The watch home screen shows START greyed out and Calibration required until the gun has been calibrated on this watch. If you get a new watch, calibrate again on it. Calibrate is always available, so you can never be locked out.

Run a calibration

1. On the watch, pick the firearm, then scroll down and tap Calibrate. Read the intro and tap Begin.
2. The watch starts its workout session and sensor. You get four seconds to settle.
3. Listen for beep, beep, BEEP. Fire exactly one shot after the long beep ends. The screen says FIRE and a 1.20 second window is open.
4. Two rising tones mean the shot counted. Two falling tones mean it did not and the same shot is repeated.
5. Repeat until you have five clean shots. You get up to twelve attempts.
6. The result screen lists every attempt, the median peak, the floor and the energy. Tap Accept to save them to the gun.

End keeps what the run saw so far and saves it for review. Cancel discards the run. Neither changes the gun until you tap Accept on a finished run.

Chapter 4

Time a string

1. On the watch home screen, check the firearm name under START. Tap START.
2. Shooter ready: low tones count down your prep time. You set the length in Settings.
3. Stand by: take your start position and hold still. The watch reads which way gravity points during the half second before the beep to work out your start position.
4. A random delay, then the start signal. The clock starts at the signal.
5. Shoot. The screen shows the running time, your shot count and the latest split.
6. Tap STOP when you are done.

The result screen

Swipe left on any shot to delete it, for example a neighbour’s shot or a bumped bench. Then choose Save to keep the string, or Discard if the count is wrong (chapter 6).

Chapter 5

Tag labels

Labels turn a string into something you can learn from later. They are added on the phone after the fact and are never placed on the sensor data.

Start position

Open Sessions, tap the string, and look at the Capture block. The watch reads one of these:

If the watch read it right, leave it. Leaving it as sensed counts as confirmed. If it got it wrong, tap the right one. Both values are kept, and the pair is what teaches the watch. If it could not read the position it says Not read, and you can set it yourself.

String actions

Further down the string page, tap Edit string and build the list of what you did, in order.

1. Pick the starting position.
2. The editor offers only actions that can follow the last one. After Low ready; slide forward and slide back are offered as conditions of the low ready not next steps.
3. Tap Fire a string and enter how many rounds. Use Dry fire for a trigger press with no round fired.
4. Keep going: reload, malfunction, holster, draw, and so on. Undo last removes the latest one.
5. Tap Save.

What the colors mean

Each action in the string list is a colored pill, so the order of a string can be read at a glance. The colors are fixed:

A few other colors on the phone carry meaning too. None of them is a grade of your shooting.

Chapter 6

Fix the shot count

If the detector counted a handling noise as a shot, or missed a shot, tell the app. Your correction is the only ground truth it can get.

On the watch, right after a string

1. On the result screen tap Discard.
2. Choose a reason. Un-Needed deletes the string. Incorrect data tells the app the detector was wrong and allows for editing.
3. With Incorrect data, turn the Digital Crown to the number of shots you fired. If you do not remember, tap Unknown. A wrong count is worse than none.
4. When Complete, Tap Save.

On the phone, any time later

1. Open the string in Sessions. Under Count, tap Correct this count.
2. Set Shots fired with the stepper, or I’m not sure if unsure. Zero is a valid answer.
3. When Complete, Tap Save.

A corrected string is kept out of your stats. The recorded data and both counts stay. If you change your mind, tap Actually, the count was right.

Chapter 7

Trace Lab

Trace Lab replays a string’s recorded sensor data through the same detector the watch ran, so you can see why a shot was counted or missed without going back to the range.

Open it from Sessions: tap a string, then Open in trace lab. The link only appears for strings that have a recording. Raw traces are on by default, and calibration always keeps one (chapter 8).

What you see

The four sliders

Using it

1. Open a string where the count was wrong, such as one you corrected.
2. Look at the chart. Check each lime line sits on a real shot.
3. Move the sliders until the count matches what you know you fired.
4. Look at what changed. A false shot that disappears at a modest floor is a good sign. A real shot that disappears means the floor is too high.

Saving your settings

Save these as the firearm’s profile writes the peak floor and energy floor into the calibration of the watch that recorded the string, and the refractory into the gun. Sigma is not saved. This changes how every future string on that gun and watch is detected. There is no undo. To go back, calibrate again (chapter 3).

Chapter 8

Par drill, settings and headsets

Par drill

Choose Par drill on the watch home screen for a timer with a par time and no shot detection. It records nothing. Use it for dry-fire practice.

Settings

Bluetooth headsets and electronic muffs

Bluetooth adds roughly 150 to 200 ms between the app playing the beep and you hearing it. The app compensates, but the figure is only as good as what it knows about your headset. To measure it, go to Settings, Start signal, and run Measure. A metronome ticks and you tap the watch in time.

• First measure your own tap bias on the watch speaker, with the headset disconnected. This is done once.
• Then measure each headset. The result is the difference from your baseline.
• If your taps are inconsistent (about 40 ms of spread or more) the screen tells you to run it again.
• If the headset connects in a narrow telephony mode the beep is quiet. Reconnect it as a media device.

Until a headset is measured, draw and total are marked estimated on the result. Splits are unaffected.

Chapter 9

Your data

Where it lives

Strings, firearms, calibrations and sensor recordings are kept in one folder. On a phone that has iCloud Drive available to the app, that folder is in Files, iCloud Drive, Sub One. It survives deleting and reinstalling the app, which matters because TestFlight builds expire.

To check, open the phone’s Watch tab. Under Stored, the Kept in row reads iCloud Drive or This iPhone. If it says This iPhone, iCloud is not available to the app, so your strings are deleted with the app. Check that iCloud Drive is on for Sub One in iPhone Settings.

The phone’s tabs

Trace Lab

A string with a sensor recording can be re-examined in Trace Lab. See chapter 7.

Export

On the Sessions tab, tap the share icon at the top right to export your strings through the iOS share sheet. The files are JSON and CSV, named prime-factor- followed by a description. The file format is documented and versioned, so it can be read by other tools. The app has no server of its own and sends nothing to one.

Chapter 10

Troubleshooting

Guide

Quick reference

Every session

1. Phone: Watch tab shows a paired, installed, reachable watch.
2. Phone: firearm sent and received.
3. Watch: pick the gun. START is lit, so this gun is calibrated on this watch.
4. Watch: START, stand by, shoot, STOP.
5. Watch: check the shot list. Swipe away false shots.
6. Watch: Save, or Discard and enter the true count.
7. Phone: confirm the start position, tag the actions, correct anything wrong.

Calibration in one line

Five shots, one per cue, fired after the long beep. Rising tones count, falling tones repeat. At least four clean, then Accept.

Watch buttons