Introduction

Welcome to the RockTimer documentation. RockTimer is Curlvation's precision stone timing system designed for competitive and recreational curling alike. By accurately timing a stone's travel, RockTimer provides the skip and sweepers the data they need to make informed decisions in real time — before the stone crosses the far hog line.

Product Overview

RockTimer measures the time a curling stone takes to travel a defined distance on the curling sheet. This elapsed time between pre-determined points can be a reliable indicator of stone velocity, which directly predicts where the stone will come to rest. When skips and sweepers have this information, they are able to make real-time adjustments that can impact where the stone will finally come to reset.

How Timing Translates to Decisions

Every ice surface has a characteristic speed that is not only different at every venue, but is different every game as well as every end. This time is typically expressed in seconds for a stone to travel from one point to another - typically Backline to Hogline and Hogline to Hogline. RockTimer captures such times giving your team an immediate assessment:

The result is displayed immediately on the RockTimer unit, giving team members the window they need to act before it's too late.

• Backline to Hogline is typically used by sweepers to understand if they need to be sweeping immediately
• Hogline to Hogline is typically used by skips and ice crew to have a better understanding of overall ice speed and quality

Who Is RockTimer For?

• Competitive teams who want data-backed sweeping decisions to eliminate guesswork
• League and club players looking to improve their delivery consistency over time
• Coaches tracking delivery speed trends across practice sessions
• New curlers learning the connection between delivery weight and stone placement

What's in the Box

Each RockTimer unit ships with everything needed to get up and running.

Quick Start Guide

Get RockTimer operational in under five minutes.

1. Charge the unit. Before first use, fully charge RockTimer via any USB-C cable. A full charge takes approximately 90 minutes. The unit will turn on when plugged in and a lightning bolt will appear instead of a battery icon. Real-time charge percentages will be displayed as it's charging. The unit will charge whether the power is on or off but will typically charge faster if off when charging.

2. Mount the unit. Attach RockTimer to your lanyard and belt loop or to your broom using the magnetic mounting bracket.

3. Power on. Press the power button for 1 second. The display will briefly show RockTimer and the firmware version, then display that it is Ready.

4. Start timing. RockTimer by default will start timing when the screen is pressed and held and stop timing when the screen is released. Future enhancements may include timing options such as tap to start and tap to stop, as well as a tap to start, tap to split options.

5. Read the result. The elapsed time will appear on the display.

Hardware Overview

RockTimer is a compact, powerful, standalone timing device built for curling. The unit features an ESP32-S3 Chip, numerous integrated sensors, WiFi/Bluetooth connections and an AMOLED display for high-contrast large numbered readout.

Key Components

• Processor — Powerful ESP32-S3 Processor
• AMOLED Display — Bright, high contrast, large numbered display readable in all rink lighting conditions
• Power (Bottom) Button — Single button for power. Press for 1 second to turn on, hold for 2 seconds to turn off
• Menu (Top) Button — Single button for the menu. Press to open the menu, press again to save all settings and return
• USB-C Port — Charging and firmware update interface
• Micro SD Card - Record all session times to an external Micro SD Card
• Replacable Rechargable Internal Battery — Provides a full day of play (approximately 3 games) on a single charge

Specifications

Timing Basics

Understanding what RockTimer measures helps your team use the data effectively. The core measurement is a split time: the number of seconds a stone takes to travel from the detection point (hog line) to a secondary reference marker.

Split Time Reference

Ice speed is typically described in curling as the number of seconds from hog-to-hog. A "20-second ice" means a stone thrown with typical weight takes 20 seconds to travel from near hog to far hog. Your RockTimer is calibrated to your ice's target speed so that readings above or below the target translate directly into sweep recommendations.

These thresholds are configurable via the companion app and calibration mode to match your team's preferences and your ice conditions.

Reading Results

After each delivery, RockTimer's display shows the timing result and the LED transitions to the appropriate sweep call color. Results remain on screen until the next stone is detected or the display is manually reset.

Display Layout

The display shows three pieces of information after each delivery:

• Elapsed Time — The raw split time in seconds and tenths (e.g., 20.4s)
• Delta — How far the reading deviates from the calibrated target (e.g., +0.4 or −1.2)
• Recommendation — A plain-language call: SWEEP, HARD, EASE, or OK

Sweeping Decision Guide

RockTimer is a decision-support tool — the skip retains final authority on sweeping calls. This guide helps teams understand how to integrate RockTimer data into standard sweeping communication.

Communication Protocol

We recommend establishing a simple call protocol your team agrees on before the game:

1. Timer reader (vice or designated player) calls out the RockTimer result immediately after the LED changes: e.g., "Hard!" or "Off!" using the LED color as shorthand.

2. Sweepers react to the call as they would any verbal sweep call — RockTimer's output replaces or supplements the skip's initial read.

3. Skip confirms or overrides based on line (curl) considerations. RockTimer informs on weight, not line — the skip still reads break and calls for sweeping adjustments as needed.

What RockTimer Does Not Replace

• The skip's read of curl and line — RockTimer measures weight only
• Sweeper judgment on brush technique and pressure
• Ice knowledge and experience — know your sheet's quirks

FAQ

• My Unit Is not turning on - There is a feature where if the top button is pressed when turning on RockTimer, it will go into 'bootloader' mode. Unfortunately when it is in this mode, the screen does not indicate it as of the latest beta version. To get out of bootloader mode and power on normally, you will want to hold the bottom button for 15-30 seconds up to 3 times while ensuring the top button is not pressed. The unit should power on normally.
• My unit seems to have locked up - If your RockTimer has locked up and is not responding to input, simply press the power button for up to 30 sconds until it turns off. Power on normally after it turns off.
• I have other issues - Reach out. While RockTimer is in Beta, we are especially interested in feedback in order to ensure future software releases are as bug free as possible.i
• How much are software updates - All software updates are 100% free of charge. As long as your hardware supports the features, you will receive all new functionality and features as well as bug fixes that are introduced.