How to Pack and Send Accelerometer and Pedometer Data via Bluetooth LE in Tizen

Problem Understanding

The user needs to:

1. Collect accelerometer and pedometer data on a Tizen wearable
2. Package this data according to Bluetooth GATT specifications
3. Transmit the packaged data to a phone via Bluetooth LE

Solution Methods

1. Understanding GATT Characteristics:

   • While heart rate has standardized GATT characteristics, accelerometer and pedometer data don't have direct equivalents
   • You'll need to create custom GATT characteristics for your specific use case

2. Recommended Approaches:

   • For pedometer data, consider using the Running Speed and Cadence Profile (RSCP)
   • For accelerometer data, you may need to define your own custom service and characteristics
   • Refer to the Bluetooth SIG specifications for guidance: Bluetooth GATT Specifications

3. Implementation Steps:

   • Define a custom UUID for your service
   • Create characteristics for each sensor data type
   • Package the data in a consistent format (e.g., JSON or binary)
   • Implement the Bluetooth LE service following Tizen's documentation

Code Examples

// Example of defining a custom service and characteristic
static const char *CUSTOM_SERVICE_UUID = "00001821-0000-1000-8000-00805f9b34fb";
static const char *ACCELEROMETER_CHAR_UUID = "00002a21-0000-1000-8000-00805f9b34fb";

// Example of packaging accelerometer data
void package_accelerometer_data(double x, double y, double z, uint8_t *buffer) {
    // Convert doubles to network byte order and store in buffer
    // Add any necessary flags or metadata
}

Additional Tips

• When defining custom characteristics, document your format clearly for the receiving device
• Consider data compression if transmission bandwidth is a concern
• Test your implementation with various Bluetooth LE scanners to ensure compatibility
• For Tizen-specific implementation details, refer to the updated documentation at Samsung Tizen OS Developer Portal