Sensor Storm

Sensor Storm is an Android app developed for streaming raw (Little Endian) data from inboard sensors. All available sensor data is streamed through UDP packets on a real-time basis. No sensor data is broken into multiple packets except for the image data. All raw sensor data is prefixed with a sensor code of type int32_t (int) followed by the data which is at the same exact order as mentioned in the Android sensor event values.

Sensor code of each sensor depends on the constant values assigned to each sensor by the Android sensor type code. For location sensor and camera sensor, the sensor code are 120 and 121. The maximum size of an expected UDP packet is 65500. All raw sensor values are 32-bit IEEE 754 floating point numbers (float) except for camera and location.

For better precision, location data is send as three 64-bit IEEE double precision floating-point number (double) representing latitude, longitude and altitude. If camera produce images that can't be accommodated in a single UDP packet, then it is fragmented and send in different packets.

The camera sensor data starts with the sensor code 121 followed by the image sequence number (1 - Int.MAX_VALUE), image size in bytes (1 - Int.MAX_VALUE), index value of fragment in image data (0 - Int.MAX_VALUE), fragment size (1 - Int.MAX_VALUE) - all as int32_t (int) values.

Download

Amazon App Store

Supported Android Sensors

1. Camera (352 * 288 JPEG)
2. Location
3. Acceleration
4. Rotation Vector
5. Light Intensity
6. Gravity
7. Magnetic Field
8. Ambient Temperature
9. Relative Humidity
10. Pressure
11. Proximity

Examples

C++ Example - Parsing Linear Acceleration and Location from UDP packet

#define LINEAR_ACCELERATION 10
#define LOCATION 120

float acceleration[3];
double position[3];

void processData(uint8_t dataBuffer[], int size)
{
    int index = 0;
    while (index < size)
    {
        int32_t sensorCode;
        memcpy(&sensorCode, &dataBuffer[index], sizeof(sensorCode));
        index += sizeof(sensorCode);

        if(sensorCode == LINEAR_ACCELERATION)
        {   
            memcpy(&acceleration[0], &dataBuffer[index], sizeof(acceleration));
            index += sizeof(acceleration);         
            std::cout<<"Acceleration "<<acceleration[0]<<" "<<acceleration[1]<<" "<<acceleration[2]<<std::endl;
          
        }
        else if(sensorCode == LOCATION)
        {   
            memcpy(&position[0], &dataBuffer[index], sizeof(position));
            index += sizeof(position);
            std::cout<<"Position "<<position[0]<<" "<<position[1]<<" "<<position[2]<<std::endl;        
        }
    }
}

C++ Example - Parsing Image from UDP packet
Image Data Format [[..........Fragment1..........][..........Fragment2..........][..........Fragment..........]]
Note: This is a basic example for demonstration purpose assuming the image fits into a single UDP packet which is true for JPEG images of (352 * 288 - 90% quality).

#define MAX_IMAGE_SIZE 65500
#define IMAGE          121

uint8_t image[MAX_IMAGE_SIZE];
int32_t imageSize;
int32_t frameNumber;

void SensorManager::processData(uint8_t dataBuffer[], int size)
{
    int index = 0;
    while (index < size)
    {
        int32_t sensorCode;
        memcpy(&sensorCode, &dataBuffer[index], sizeof(sensorCode));
        index += sizeof(sensorCode);

        if(sensorCode == IMAGE)
        {
            memcpy(&frameNumber, &dataBuffer[index], sizeof(frameNumber));
            index += sizeof(frameNumber);
            memcpy(&imageSize, &dataBuffer[index], sizeof(imageSize));
            index += sizeof(imageSize);

            int32_t startingIndex;
            int32_t noOfBytes;
            memcpy(&startingIndex, &dataBuffer[index], sizeof(startingIndex));
            index += sizeof(startingIndex);
            memcpy(&noOfBytes, &dataBuffer[index], sizeof(noOfBytes));
            index += sizeof(noOfBytes);

            memcpy(&image[startingIndex], &dataBuffer[index], noOfBytes);
            index += noOfBytes;

            std::ofstream file("image.jpeg", std::ios::out | std::ios::binary);
            file.write((char*)&image[0], imageSize);
            file.close();
        }
    }
}