Theft alarm suggestion ☺️
I've come up with a simple way to create a bike alarm using the Karoo 2/3 and a cadence sensor.
I'm thinking of creating an extension or feature in Karoo that would allow to arm the alarm with a button, and it would then be activated by any wheel movement (i.e., cadence).
Upon detecting movement, the Karoo would emit a loud audible signal.
It could be unlocked by entering a code.
I'm not a programmer, but it seems like a simple idea, so implementing it will take 5 minutes... maybe an hour ☺️
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Hi Luka_Kemp,
What you´ve come up, already exists on other competitor devices but it uses device built-in accelerometers (not paired sensors like cadence)...
How It Works- Activation: Activate the alarm through the safety/tracking menu or the controls widget on your g***** device, requiring a PIN setup.
- Motion Detection: The device uses built-in accelerometers to detect motion. If the bike is moved while the alarm is active, it triggers.
- Alert System: The g***** device emits a loud sound, and a notification is sent to your paired smartphone, informing you of the activity.
- Disarming: To turn off the alarm, you must enter the PIN code you set up on the g***** device.
If you´re not a programmer, you can´t assume if it seems simple to implement and what time/effort it could last...but you can always suggest HH that you would like to have this on your HH device.
Cheers
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What gemini answered:
Building a theft alarm for the Hammerhead Karoo via the SDK is a clever use of the hardware’s sensors. Since the Karoo runs on a modified version of Android, you will be leveraging the Karoo System SDK to interact with the physical buttons, screen, and system events.
Here is a conceptual architectural guide and the technical steps to build this extension.
1. Project Architecture
To make this work seamlessly, your extension needs three main components:
The Service: A background service that monitors the accelerometer even when the screen is off.
The UI (Widget/App): A custom "Control Center" widget or a standalone app page for ARM/DISARM actions.
The PIN Overlay: A secure Activity that launches automatically when motion is detected or when attempting to disarm.
2. Technical Implementation
Phase A: Motion Detection
The Karoo has a built-in accelerometer. You will use the standard Android SensorManager. To prevent "ghost" alarms (like the wind blowing), you should implement a threshold for the magnitude of acceleration.
The total acceleration a can be calculated as:
If a exceeds a predefined threshold (e.g., 1.5g) while the state is ARMED, the alarm triggers.
Phase B: The Alert System
Since the Karoo doesn't have a massive internal speaker, you want to maximize the Piezo buzzer or the audio channel if the user has a paired Bluetooth headset/Di2 system.
Visuals: Flash the screen at max brightness with a red "THEFT DETECTED" warning.
Audio: Use ToneGenerator or MediaPlayer to loop a high-frequency screech.
Notifications: Use the Karoo SDK’s notification wrapper to push an alert to the paired phone via the companion app link.
3. Recommended SDK Workflow
Step 1: Define the Alarm Service
class TheftAlarmService : Service(), SensorEventListener {
private lateinit var sensorManager: SensorManager
private var isArmed = falseoverride fun onSensorChanged(event: SensorEvent) {
if (isArmed && isSignificantMovement(event)) {
triggerAlarm()
}
}
// Logic for PIN verification and siren
}
Step 2: Integration with Karoo UI
Use the Karoo Extension SDK to add a toggle to the Control Center. This allows the user to arm the device quickly before walking into a coffee shop.
Step 3: The PIN Lockdown
When the alarm is triggered, use FLAG_KEEP_SCREEN_ON and setIdentifiableNotification() to ensure the app stays in the foreground.
Disarm Logic: Disable the physical buttons (Back/Lap) via the SDK’s onKeyDown override if the alarm is active, forcing the thief to interact with the PIN screen (which they won't know).
4. Logical Flow & Edge Cases
Feature Logic
PIN Setup Stored in EncryptedSharedPreferences so it can't be bypassed by simple file browsing.
Battery Safety If the battery hits <5%, the alarm should auto-disarm or send a final "Low Battery" push to the phone.
Sensitivity Include a slider in your extension settings to adjust "High" (sensitive) to "Low" (heavy wind/train station).
5. Deployment Hardware Considerations
Vibration: Karoo's haptic motor should be set to a continuous loop during the alarm to add physical feedback.
GPS Tracking: Once triggered, the extension should force the GPS to "High Accuracy" mode and broadcast the coordinates to the paired smartphone every 30 seconds.
Pro-Tip: Since the Karoo is easily removable from its mount, your code should also monitor the Charging State. If a thief removes the Karoo from a smart mount (cutting power), that should act as an immediate secondary trigger for the alarm.
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