Gepetto Slot Car Lap Counter

Gepetto really loves slot car racing. He created this app so he can have a reliable lap timer and lap counter for slot car races. It requires no registration and is a pure phone-based solution.

If you have comments and / or suggestions for improvements, please contact Gepetto via the feedback link on the play store. He is always looking for suggestions.

The main components: a Camera, a Steward component, a Driver's component and a Billboard component. They can all run on a single phone or be distributed across multiple phones using Google's Quick Share.

- The Camera: Should be placed on top of a starter bridge overlooking the track.

- The Steward Component: Used to start or stop a race and view standings, lap times, etc.

- The Driver Component: Intended for a single racer, it shows the racer's lap times, number of laps, and best lap. It can also optionally announce lap times.

- The Billboard Component: Intended for display in a big screen, it shows current race standings and the current heat's results dynamically.

These components communicate via Google's Quick Share. That means the devices must be on the same wifi network. They also need to be in proximity (same room) to each other.

You can run single-heat races, or even multi-heat races. The app will shuffle and distribute the drivers evenly across the heats.

The Camera Component

The Camera Component is the most important part of the system. You start by taking a baseline picture of the track. The camera detects when cars pass in front of it by dynamically comparing the live feed with this baseline picture.

Position your phone on top of the start/finish bridge and tap the Camera icon. You should see an image of the track with yellow overlays, which represent the detection zones. After that, take the baseline picture. The flag icon will turn from gray to red, meaning you are ready to start. If you tap the red flag, it will turn green and begin to count and time the laps.

You can pinch to zoom until each lane is aligned within the guides shown in the camera view. This works best if your phone supports a wide-angle camera; otherwise, you may have to position your phone higher. You can adjust the yellow detection zones to make them more precise. The granularity of the timed laps is approximately 1/30 of a second, depending on your phone's performance.

The Steward Component

The Steward component can be started on another Android device. Simply tap on the checkered flag icon to launch it. It will take a few seconds to connect with the Camera component. Once connected, you can take the baseline picture, start or stop the race, and view lap counters and standings for all tracks directly from the second device. Tapping on a specific track will bring up the Driver's component for that lane.

The Driver Component

In the Driver component, you will see much of the same information available in the Steward component, but you cannot start or stop the race. You can optionally tap the speaker icon to have the device read the lap times out loud. Earphones are recommended.

The Billboard Component

When running on an Android TV device or TV that supports at least Android 12 apps, it allows display of the race's standings and the current heat's standings. It

also allows a driver component to run in a large screen. The Billboard component can also run on any large device that supports Android 12, such as a large tablet or a Chromebook laptop.

Running multiple components on a single device

While not the ideal setup, you can run the Camera and Steward components side-by-side. To do this, place your phone in landscape orientation on the bridge and set up the Camera component. Once ready, tap the Steward icon to bring up the Steward component in a split-screen view.

Similarly, if you want to run the Camera and Driver components side-by-side, set up the camera as described above and then tap on the desired track info area to launch the Driver component alongside the camera feed.