microbit: code scrub of MicroBitAccelerometer gesture recognition code

- updated acceleration threshold event names to reflect numeric values e.g.
    GESTURE_3G, GESTURE_6G, GESTURE_8G.
  - Add scoping to elements of SimpleGesture enum.
  - Code scrub of code layout caused by editor with incorrect configuration.
  - rename of internal state variables and functions to better reflect use.
  - added clarification to some comments.
master
Joe Finney 2016-01-05 15:44:57 +00:00
parent 1b18ac8641
commit d3587d888c
2 changed files with 365 additions and 360 deletions

View File

@ -5,8 +5,8 @@
#include "MicroBitComponent.h"
/**
* Relevant pin assignments
*/
* Relevant pin assignments
*/
#define MICROBIT_PIN_ACCEL_DATA_READY P0_28
/*
@ -29,8 +29,8 @@
/**
* MMA8653 constants
*/
* MMA8653 constants
*/
#define MMA8653_WHOAMI_VAL 0x5A
#define MMA8653_SAMPLE_RANGES 3
@ -39,42 +39,42 @@
/*
* Accelerometer events
*/
#define MICROBIT_ACCELEROMETER_EVT_DATA_UPDATE 1
#define MICROBIT_ACCELEROMETER_EVT_DATA_UPDATE 1
/*
* Gesture events
*/
#define MICROBIT_ACCELEROMETER_EVT_TILT_UP 1
#define MICROBIT_ACCELEROMETER_EVT_TILT_DOWN 2
#define MICROBIT_ACCELEROMETER_EVT_TILT_LEFT 3
#define MICROBIT_ACCELEROMETER_EVT_TILT_RIGHT 4
#define MICROBIT_ACCELEROMETER_EVT_FACE_UP 5
#define MICROBIT_ACCELEROMETER_EVT_FACE_DOWN 6
#define MICROBIT_ACCELEROMETER_EVT_FREEFALL 7
#define MICROBIT_ACCELEROMETER_EVT_WHEEE 8
#define MICROBIT_ACCELEROMETER_EVT_SICK 9
#define MICROBIT_ACCELEROMETER_EVT_UNCONSCIOUS 10
#define MICROBIT_ACCELEROMETER_EVT_SHAKE 11
#define MICROBIT_ACCELEROMETER_EVT_TILT_UP 1
#define MICROBIT_ACCELEROMETER_EVT_TILT_DOWN 2
#define MICROBIT_ACCELEROMETER_EVT_TILT_LEFT 3
#define MICROBIT_ACCELEROMETER_EVT_TILT_RIGHT 4
#define MICROBIT_ACCELEROMETER_EVT_FACE_UP 5
#define MICROBIT_ACCELEROMETER_EVT_FACE_DOWN 6
#define MICROBIT_ACCELEROMETER_EVT_FREEFALL 7
#define MICROBIT_ACCELEROMETER_EVT_3G 8
#define MICROBIT_ACCELEROMETER_EVT_6G 9
#define MICROBIT_ACCELEROMETER_EVT_8G 10
#define MICROBIT_ACCELEROMETER_EVT_SHAKE 11
/*
* Gesture recogniser constants
*/
#define MICROBIT_ACCELEROMETER_REST_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_TILT_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE 1000
#define MICROBIT_ACCELEROMETER_WHEEE_TOLERANCE 3000
#define MICROBIT_ACCELEROMETER_SICK_TOLERANCE 5000
#define MICROBIT_ACCELEROMETER_UNCONSCIOUS_TOLERANCE 8000
#define MICROBIT_ACCELEROMETER_GESTURE_DAMPING 10
#define MICROBIT_ACCELEROMETER_SHAKE_DAMPING 10
#define MICROBIT_ACCELEROMETER_REST_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_TILT_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE 200
#define MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE 1000
#define MICROBIT_ACCELEROMETER_3G_TOLERANCE 3072
#define MICROBIT_ACCELEROMETER_6G_TOLERANCE 6144
#define MICROBIT_ACCELEROMETER_8G_TOLERANCE 8192
#define MICROBIT_ACCELEROMETER_GESTURE_DAMPING 10
#define MICROBIT_ACCELEROMETER_SHAKE_DAMPING 10
#define MICROBIT_ACCELEROMETER_REST_THRESHOLD (MICROBIT_ACCELEROMETER_REST_TOLERANCE * MICROBIT_ACCELEROMETER_REST_TOLERANCE)
#define MICROBIT_ACCELEROMETER_FREEFALL_THRESHOLD (MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE * MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE)
#define MICROBIT_ACCELEROMETER_WHEEE_THRESHOLD (MICROBIT_ACCELEROMETER_WHEEE_TOLERANCE * MICROBIT_ACCELEROMETER_WHEEE_TOLERANCE)
#define MICROBIT_ACCELEROMETER_SICK_THRESHOLD (MICROBIT_ACCELEROMETER_SICK_TOLERANCE * MICROBIT_ACCELEROMETER_SICK_TOLERANCE)
#define MICROBIT_ACCELEROMETER_UNCONSCIOUS_THRESHOLD (MICROBIT_ACCELEROMETER_UNCONSCIOUS_TOLERANCE * MICROBIT_ACCELEROMETER_UNCONSCIOUS_TOLERANCE)
#define MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD 4
#define MICROBIT_ACCELEROMETER_REST_THRESHOLD (MICROBIT_ACCELEROMETER_REST_TOLERANCE * MICROBIT_ACCELEROMETER_REST_TOLERANCE)
#define MICROBIT_ACCELEROMETER_FREEFALL_THRESHOLD (MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE * MICROBIT_ACCELEROMETER_FREEFALL_TOLERANCE)
#define MICROBIT_ACCELEROMETER_3G_THRESHOLD (MICROBIT_ACCELEROMETER_3G_TOLERANCE * MICROBIT_ACCELEROMETER_3G_TOLERANCE)
#define MICROBIT_ACCELEROMETER_6G_THRESHOLD (MICROBIT_ACCELEROMETER_6G_TOLERANCE * MICROBIT_ACCELEROMETER_6G_TOLERANCE)
#define MICROBIT_ACCELEROMETER_8G_THRESHOLD (MICROBIT_ACCELEROMETER_8G_TOLERANCE * MICROBIT_ACCELEROMETER_8G_TOLERANCE)
#define MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD 4
struct MMA8653Sample
{
@ -100,68 +100,68 @@ extern const MMA8653SampleRateConfig MMA8653SampleRate[];
enum BasicGesture
{
NONE,
UP,
DOWN,
LEFT,
RIGHT,
FACE_UP,
FACE_DOWN,
FREEFALL,
WHEEE,
SICK,
UNCONSCIOUS,
SHAKE
GESTURE_NONE,
GESTURE_UP,
GESTURE_DOWN,
GESTURE_LEFT,
GESTURE_RIGHT,
GESTURE_FACE_UP,
GESTURE_FACE_DOWN,
GESTURE_FREEFALL,
GESTURE_3G,
GESTURE_6G,
GESTURE_8G,
GESTURE_SHAKE
};
struct ShakeHistory
{
uint16_t shaken:1,
x:1,
y:1,
z:1,
count:4,
timer:8;
uint16_t shaken:1,
x:1,
y:1,
z:1,
count:4,
timer:8;
};
/**
* Class definition for MicroBit Accelerometer.
*
* Represents an implementation of the Freescale MMA8653 3 axis accelerometer
* Also includes basic data caching and on demand activation.
*/
* Class definition for MicroBit Accelerometer.
*
* Represents an implementation of the Freescale MMA8653 3 axis accelerometer
* Also includes basic data caching and on demand activation.
*/
class MicroBitAccelerometer : public MicroBitComponent
{
/**
* Unique, enumerated ID for this component.
* Used to track asynchronous events in the event bus.
*/
MMA8653Sample sample; // The last sample read.
DigitalIn int1; // Data ready interrupt.
uint16_t address; // I2C address of this accelerometer.
uint16_t samplePeriod; // The time between samples, in milliseconds.
uint8_t sampleRange; // The sample range of the accelerometer in g.
uint8_t sigma; // the number of ticks that the instantaneous gesture has been stable.
BasicGesture gesture; // the current, filtered orientation of the device.
BasicGesture iGesture; // the last instantaneous orientation recorded.
ShakeHistory shake; // State information needed to detect shake events.
* Unique, enumerated ID for this component.
* Used to track asynchronous events in the event bus.
*/
MMA8653Sample sample; // The last sample read.
DigitalIn int1; // Data ready interrupt.
uint16_t address; // I2C address of this accelerometer.
uint16_t samplePeriod; // The time between samples, in milliseconds.
uint8_t sampleRange; // The sample range of the accelerometer in g.
uint8_t sigma; // the number of ticks that the instantaneous gesture has been stable.
BasicGesture lastGesture; // the last, stable gesture recorded.
BasicGesture currentGesture; // the instantaneous, unfiltered gesture detected.
ShakeHistory shake; // State information needed to detect shake events.
public:
/**
* Constructor.
* Create an accelerometer representation with the given ID.
* @param id the ID of the new object.
* @param address the default base address of the accelerometer.
*
* Example:
* @code
* accelerometer(MICROBIT_ID_ACCELEROMETER, MMA8653_DEFAULT_ADDR)
* @endcode
*/
* Constructor.
* Create an accelerometer representation with the given ID.
* @param id the ID of the new object.
* @param address the default base address of the accelerometer.
*
* Example:
* @code
* accelerometer(MICROBIT_ID_ACCELEROMETER, MMA8653_DEFAULT_ADDR)
* @endcode
*/
MicroBitAccelerometer(uint16_t id, uint16_t address);
/**
* Configures the accelerometer for G range and sample rate defined
* in this object. The nearest values are chosen to those defined
@ -173,26 +173,26 @@ class MicroBitAccelerometer : public MicroBitComponent
int configure();
/**
* Reads the acceleration data from the accelerometer, and stores it in our buffer.
* This is called by the tick() member function, if the interrupt is set.
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the read request fails.
*/
* Reads the acceleration data from the accelerometer, and stores it in our buffer.
* This is called by the tick() member function, if the interrupt is set.
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the read request fails.
*/
int update();
/**
* Attempts to set the sample rate of the accelerometer to the specified value (in ms).
* n.b. the requested rate may not be possible on the hardware. In this case, the
* nearest lower rate is chosen.
* @param period the requested time between samples, in milliseconds.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the request fails.
*/
* Attempts to set the sample rate of the accelerometer to the specified value (in ms).
* n.b. the requested rate may not be possible on the hardware. In this case, the
* nearest lower rate is chosen.
* @param period the requested time between samples, in milliseconds.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the request fails.
*/
int setPeriod(int period);
/**
* Reads the currently configured sample rate of the accelerometer.
* @return The time between samples, in milliseconds.
*/
* Reads the currently configured sample rate of the accelerometer.
* @return The time between samples, in milliseconds.
*/
int getPeriod();
/**
@ -211,116 +211,116 @@ class MicroBitAccelerometer : public MicroBitComponent
int getRange();
/**
* Attempts to determine the 8 bit ID from the accelerometer.
* @return the 8 bit ID returned by the accelerometer, or MICROBIT_I2C_ERROR if the request fails.
*
* Example:
* @code
* uBit.accelerometer.whoAmI();
* @endcode
*/
* Attempts to determine the 8 bit ID from the accelerometer.
* @return the 8 bit ID returned by the accelerometer, or MICROBIT_I2C_ERROR if the request fails.
*
* Example:
* @code
* uBit.accelerometer.whoAmI();
* @endcode
*/
int whoAmI();
/**
* Reads the X axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the X axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getX();
* @endcode
*/
* Reads the X axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the X axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getX();
* @endcode
*/
int getX();
/**
* Reads the Y axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Y axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getY();
* @endcode
*/
* Reads the Y axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Y axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getY();
* @endcode
*/
int getY();
/**
* Reads the Z axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Z axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getZ();
* @endcode
*/
* Reads the Z axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Z axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getZ();
* @endcode
*/
int getZ();
/**
* Reads the last recorded gesture detected.
* @return The last gesture detected.
*
* Example:
* @code
* if (uBit.accelerometer.getGesture() == SHAKE)
* @endcode
*/
* Reads the last recorded gesture detected.
* @return The last gesture detected.
*
* Example:
* @code
* if (uBit.accelerometer.getGesture() == SHAKE)
* @endcode
*/
BasicGesture getGesture();
/**
* periodic callback from MicroBit idle thread.
* Check if any data is ready for reading by checking the interrupt flag on the accelerometer
*/
* periodic callback from MicroBit idle thread.
* Check if any data is ready for reading by checking the interrupt flag on the accelerometer
*/
virtual void idleTick();
/**
* Returns 0 or 1. 1 indicates data is waiting to be read, zero means data is not ready to be read.
*/
* Returns 0 or 1. 1 indicates data is waiting to be read, zero means data is not ready to be read.
*/
virtual int isIdleCallbackNeeded();
private:
/**
* Issues a standard, 2 byte I2C command write to the accelerometer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to write to.
* @param value The value to write.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the the write request failed.
*/
* Issues a standard, 2 byte I2C command write to the accelerometer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to write to.
* @param value The value to write.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the the write request failed.
*/
int writeCommand(uint8_t reg, uint8_t value);
/**
* Issues a read command into the specified buffer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to access.
* @param buffer Memory area to read the data into.
* @param length The number of bytes to read.
* @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER or MICROBIT_I2C_ERROR if the the read request failed.
*/
* Issues a read command into the specified buffer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to access.
* @param buffer Memory area to read the data into.
* @param length The number of bytes to read.
* @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER or MICROBIT_I2C_ERROR if the the read request failed.
*/
int readCommand(uint8_t reg, uint8_t* buffer, int length);
/**
* Updates the basic gesture recognizer. This performs instantaneous pose recognition, and also some low pass filtering to promote
* stability.
*/
void updateGesture();
/**
* Updates the basic gesture recognizer. This performs instantaneous pose recognition, and also some low pass filtering to promote
* stability.
*/
void updateGesture();
/**
* Service function. Calculates the current scalar acceleration of the device (x^2 + y^2 + z^2).
* It does not, however, square root the result, as this is a relatively high cost operation.
* This is left to application code should it be needed.
* @return the sum of the square of the acceleration of the device across all axes.
*/
int instantaneousAcceleration2();
/**
* Service function. Calculates the current scalar acceleration of the device (x^2 + y^2 + z^2).
* It does not, however, square root the result, as this is a relatively high cost operation.
* This is left to application code should it be needed.
* @return the sum of the square of the acceleration of the device across all axes.
*/
int instantaneousAccelerationSquared();
/**
* Service function. Determines the best guess posture of the device based on instantaneous data.
* This makes no use of historic data, and forms this input to th filter implemented in updateGesture().
* @return A best guess of the curret posture of the device, based on instanataneous data.
*/
BasicGesture instantaneousPosture();
/**
* Service function. Determines the best guess posture of the device based on instantaneous data.
* This makes no use of historic data, and forms this input to th filter implemented in updateGesture().
* @return A best guess of the curret posture of the device, based on instanataneous data.
*/
BasicGesture instantaneousPosture();
};
#endif

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@ -1,20 +1,20 @@
/**
* Class definition for MicroBit Accelerometer.
*
* Represents an implementation of the Freescale MMA8653 3 axis accelerometer
* Also includes basic data caching and on demand activation.
*/
* Class definition for MicroBit Accelerometer.
*
* Represents an implementation of the Freescale MMA8653 3 axis accelerometer
* Also includes basic data caching and on demand activation.
*/
#include "MicroBit.h"
/**
* Configures the accelerometer for G range and sample rate defined
* in this object. The nearest values are chosen to those defined
* that are supported by the hardware. The instance variables are then
* updated to reflect reality.
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the accelerometer could not be configured.
*/
* Configures the accelerometer for G range and sample rate defined
* in this object. The nearest values are chosen to those defined
* that are supported by the hardware. The instance variables are then
* updated to reflect reality.
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the accelerometer could not be configured.
*/
int MicroBitAccelerometer::configure()
{
const MMA8653SampleRangeConfig *actualSampleRange;
@ -50,7 +50,7 @@ int MicroBitAccelerometer::configure()
result = writeCommand(MMA8653_CTRL_REG1, 0x00);
if (result != 0)
return MICROBIT_I2C_ERROR;
// Enable high precisiosn mode. This consumes a bit more power, but still only 184 uA!
result = writeCommand(MMA8653_CTRL_REG2, 0x10);
if (result != 0)
@ -70,7 +70,7 @@ int MicroBitAccelerometer::configure()
result = writeCommand(MMA8653_XYZ_DATA_CFG, actualSampleRange->xyz_data_cfg);
if (result != 0)
return MICROBIT_I2C_ERROR;
// Bring the device back online, with 10bit wide samples at the requested frequency.
result = writeCommand(MMA8653_CTRL_REG1, actualSampleRate->ctrl_reg1 | 0x01);
if (result != 0)
@ -80,31 +80,31 @@ int MicroBitAccelerometer::configure()
}
/**
* Issues a standard, 2 byte I2C command write to the accelerometer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to write to.
* @param value The value to write.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the the write request failed.
*/
* Issues a standard, 2 byte I2C command write to the accelerometer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to write to.
* @param value The value to write.
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR if the the write request failed.
*/
int MicroBitAccelerometer::writeCommand(uint8_t reg, uint8_t value)
{
uint8_t command[2];
command[0] = reg;
command[1] = value;
return uBit.i2c.write(address, (const char *)command, 2);
}
/**
* Issues a read command into the specified buffer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to access.
* @param buffer Memory area to read the data into.
* @param length The number of bytes to read.
* @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER or MICROBIT_I2C_ERROR if the the read request failed.
*/
* Issues a read command into the specified buffer.
* Blocks the calling thread until complete.
*
* @param reg The address of the register to access.
* @param buffer Memory area to read the data into.
* @param length The number of bytes to read.
* @return MICROBIT_OK on success, MICROBIT_INVALID_PARAMETER or MICROBIT_I2C_ERROR if the the read request failed.
*/
int MicroBitAccelerometer::readCommand(uint8_t reg, uint8_t* buffer, int length)
{
int result;
@ -124,16 +124,16 @@ int MicroBitAccelerometer::readCommand(uint8_t reg, uint8_t* buffer, int length)
}
/**
* Constructor.
* Create an accelerometer representation with the given ID.
* @param id the ID of the new object.
* @param address the default base address of the accelerometer.
*
* Example:
* @code
* accelerometer(MICROBIT_ID_ACCELEROMETER, MMA8653_DEFAULT_ADDR)
* @endcode
*/
* Constructor.
* Create an accelerometer representation with the given ID.
* @param id the ID of the new object.
* @param address the default base address of the accelerometer.
*
* Example:
* @code
* accelerometer(MICROBIT_ID_ACCELEROMETER, MMA8653_DEFAULT_ADDR)
* @endcode
*/
MicroBitAccelerometer::MicroBitAccelerometer(uint16_t id, uint16_t address) : sample(), int1(MICROBIT_PIN_ACCEL_DATA_READY)
{
// Store our identifiers.
@ -144,15 +144,15 @@ MicroBitAccelerometer::MicroBitAccelerometer(uint16_t id, uint16_t address) : sa
this->samplePeriod = 20;
this->sampleRange = 2;
// Initialise gesture history
this->sigma = 0;
this->gesture = NONE;
this->iGesture = NONE;
this->shake.x = 0;
this->shake.y = 0;
this->shake.z = 0;
this->shake.count = 0;
this->shake.timer = 0;
// Initialise gesture history
this->sigma = 0;
this->lastGesture = GESTURE_NONE;
this->currentGesture = GESTURE_NONE;
this->shake.x = 0;
this->shake.y = 0;
this->shake.z = 0;
this->shake.count = 0;
this->shake.timer = 0;
// Configure and enable the accelerometer.
if (this->configure() == MICROBIT_OK)
@ -160,14 +160,14 @@ MicroBitAccelerometer::MicroBitAccelerometer(uint16_t id, uint16_t address) : sa
}
/**
* Attempts to determine the 8 bit ID from the accelerometer.
* @return the 8 bit ID returned by the accelerometer, or MICROBIT_I2C_ERROR if the request fails.
*
* Example:
* @code
* uBit.accelerometer.whoAmI();
* @endcode
*/
* Attempts to determine the 8 bit ID from the accelerometer.
* @return the 8 bit ID returned by the accelerometer, or MICROBIT_I2C_ERROR if the request fails.
*
* Example:
* @code
* uBit.accelerometer.whoAmI();
* @endcode
*/
int MicroBitAccelerometer::whoAmI()
{
uint8_t data;
@ -181,11 +181,11 @@ int MicroBitAccelerometer::whoAmI()
}
/**
* Reads the acceleration data from the accelerometer, and stores it in our buffer.
* This is called by the tick() member function, if the interrupt is set!
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the read request fails.
*/
* Reads the acceleration data from the accelerometer, and stores it in our buffer.
* This is called by the tick() member function, if the interrupt is set!
*
* @return MICROBIT_OK on success, MICROBIT_I2C_ERROR is the read request fails.
*/
int MicroBitAccelerometer::update()
{
int8_t data[6];
@ -199,7 +199,7 @@ int MicroBitAccelerometer::update()
sample.x = data[0];
sample.y = data[2];
sample.z = data[4];
// Normalize the data in the 0..1024 range.
sample.x *= 8;
sample.y *= 8;
@ -221,8 +221,8 @@ int MicroBitAccelerometer::update()
sample.y *= this->sampleRange;
sample.z *= this->sampleRange;
// Update gesture tracking
updateGesture();
// Update gesture tracking
updateGesture();
// Indicate that a new sample is available
MicroBitEvent e(id, MICROBIT_ACCELEROMETER_EVT_DATA_UPDATE);
@ -237,11 +237,11 @@ int MicroBitAccelerometer::update()
*
* @return the sum of the square of the acceleration of the device across all axes.
*/
int
MicroBitAccelerometer::instantaneousAcceleration2()
int
MicroBitAccelerometer::instantaneousAccelerationSquared()
{
// Use pythagoras theorem to determine the combined force acting on the device.
return (int)sample.x*(int)sample.x + (int)sample.y*(int)sample.y + (int)sample.z*(int)sample.z;
// Use pythagoras theorem to determine the combined force acting on the device.
return (int)sample.x*(int)sample.x + (int)sample.y*(int)sample.y + (int)sample.z*(int)sample.z;
}
/**
@ -250,105 +250,110 @@ MicroBitAccelerometer::instantaneousAcceleration2()
*
* @return A best guess of the current posture of the device, based on instantaneous data.
*/
BasicGesture
BasicGesture
MicroBitAccelerometer::instantaneousPosture()
{
int force = instantaneousAcceleration2();
bool shakeDetected = false;
int force = instantaneousAccelerationSquared();
bool shakeDetected = false;
// Test for shake events.
if ((sample.x < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.x) || (sample.x > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.x))
{
shakeDetected = true;
shake.x = !shake.x;
}
// Test for shake events.
// We detect a shake by measuring zero crossings in each axis. In other words, if we see a strong acceleration to the left followed by
// a string acceleration to the right, then we can infer a shake. Similarly, we can do this for each acxis (left/right, up/down, in/out).
//
// If we see enough zero crossings in succession (MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD), then we decide that the device
// has been shaken.
if ((sample.x < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.x) || (sample.x > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.x))
{
shakeDetected = true;
shake.x = !shake.x;
}
if ((sample.y < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.y) || (sample.y > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.y))
{
shakeDetected = true;
shake.y = !shake.y;
}
if ((sample.y < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.y) || (sample.y > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.y))
{
shakeDetected = true;
shake.y = !shake.y;
}
if ((sample.z < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.z) || (sample.z > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.z))
{
shakeDetected = true;
shake.z = !shake.z;
}
if ((sample.z < -MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && shake.z) || (sample.z > MICROBIT_ACCELEROMETER_SHAKE_TOLERANCE && !shake.z))
{
shakeDetected = true;
shake.z = !shake.z;
}
if (shakeDetected && shake.count < MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD && ++shake.count == MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
shake.shaken = 1;
if (++shake.timer >= MICROBIT_ACCELEROMETER_SHAKE_DAMPING)
{
shake.timer = 0;
if (shake.count > 0)
{
if(--shake.count == 0)
shake.shaken = 0;
}
}
if (shakeDetected && shake.count < MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD && ++shake.count == MICROBIT_ACCELEROMETER_SHAKE_COUNT_THRESHOLD)
shake.shaken = 1;
if (shake.shaken)
return SHAKE;
if (++shake.timer >= MICROBIT_ACCELEROMETER_SHAKE_DAMPING)
{
shake.timer = 0;
if (shake.count > 0)
{
if(--shake.count == 0)
shake.shaken = 0;
}
}
if (force < MICROBIT_ACCELEROMETER_FREEFALL_THRESHOLD)
return FREEFALL;
if (shake.shaken)
return GESTURE_SHAKE;
if (force > MICROBIT_ACCELEROMETER_UNCONSCIOUS_THRESHOLD)
return UNCONSCIOUS;
if (force < MICROBIT_ACCELEROMETER_FREEFALL_THRESHOLD)
return FREEFALL;
if (force > MICROBIT_ACCELEROMETER_SICK_THRESHOLD)
return SICK;
if (force > MICROBIT_ACCELEROMETER_3G_THRESHOLD)
return GESTURE_3G;
if (force > MICROBIT_ACCELEROMETER_WHEEE_THRESHOLD)
return WHEEE;
if (force > MICROBIT_ACCELEROMETER_6G_THRESHOLD)
return GESTURE_6G;
// Determine our posture.
if (sample.x < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return LEFT;
if (force > MICROBIT_ACCELEROMETER_8G_THRESHOLD)
return GESTURE_8G;
if (sample.x > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return RIGHT;
// Determine our posture.
if (sample.x < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_LEFT;
if (sample.y < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return DOWN;
if (sample.x > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_RIGHT;
if (sample.y > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return UP;
if (sample.y < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_DOWN;
if (sample.z < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return FACE_UP;
if (sample.y > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_UP;
if (sample.z > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return FACE_DOWN;
if (sample.z < (-1000 + MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_FACE_UP;
return NONE;
if (sample.z > (1000 - MICROBIT_ACCELEROMETER_TILT_TOLERANCE))
return GESTURE_FACE_DOWN;
return GESTURE_NONE;
}
void
void
MicroBitAccelerometer::updateGesture()
{
// Determine what it looks like we're doing based on the latest sample...
BasicGesture g = instantaneousPosture();
// Determine what it looks like we're doing based on the latest sample...
BasicGesture g = instantaneousPosture();
// Perform some low pass filtering to remove hysteresis (data flapping) effects
if (g == iGesture)
{
if (sigma < MICROBIT_ACCELEROMETER_GESTURE_DAMPING)
sigma++;
}
else
{
iGesture = g;
sigma = 0;
}
// Perform some low pass filtering to reduce jitter from any detected effects
if (g == currentGesture)
{
if (sigma < MICROBIT_ACCELEROMETER_GESTURE_DAMPING)
sigma++;
}
else
{
currentGesture = g;
sigma = 0;
}
// If we've reached threshold, update our record and raise the relevant event...
if (iGesture != gesture && sigma >= MICROBIT_ACCELEROMETER_GESTURE_DAMPING)
{
gesture = iGesture;
MicroBitEvent e(MICROBIT_ID_GESTURE, gesture);
}
// If we've reached threshold, update our record and raise the relevant event...
if (currentGesture != lastGesture && sigma >= MICROBIT_ACCELEROMETER_GESTURE_DAMPING)
{
lastGesture = currentGesture;
MicroBitEvent e(MICROBIT_ID_GESTURE, lastGesture);
}
}
/**
@ -396,50 +401,50 @@ int MicroBitAccelerometer::getRange()
}
/**
* Reads the X axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the X axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getX();
* @endcode
*/
* Reads the X axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the X axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getX();
* @endcode
*/
int MicroBitAccelerometer::getX()
{
return sample.x;
}
/**
* Reads the Y axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Y axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getY();
* @endcode
*/
* Reads the Y axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Y axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getY();
* @endcode
*/
int MicroBitAccelerometer::getY()
{
return sample.y;
}
/**
* Reads the Z axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Z axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getZ();
* @endcode
*/
* Reads the Z axis value of the latest update from the accelerometer.
* Currently limited to +/- 2g
* @return The force measured in the Z axis, in milli-g.
*
* Example:
* @code
* uBit.accelerometer.getZ();
* @endcode
*/
int MicroBitAccelerometer::getZ()
{
return sample.z;
}
/**
* Reads the last recorded gesture detected.
* @return The last gesture detected.
@ -451,13 +456,13 @@ int MicroBitAccelerometer::getZ()
*/
BasicGesture MicroBitAccelerometer::getGesture()
{
return gesture;
return lastGesture;
}
/**
* periodic callback from MicroBit clock.
* Check if any data is ready for reading by checking the interrupt flag on the accelerometer
*/
* periodic callback from MicroBit clock.
* Check if any data is ready for reading by checking the interrupt flag on the accelerometer
*/
void MicroBitAccelerometer::idleTick()
{
// Poll interrupt line from accelerometer.
@ -468,8 +473,8 @@ void MicroBitAccelerometer::idleTick()
}
/**
* Returns 0 or 1. 1 indicates data is waiting to be read, zero means data is not ready to be read.
*/
* Returns 0 or 1. 1 indicates data is waiting to be read, zero means data is not ready to be read.
*/
int MicroBitAccelerometer::isIdleCallbackNeeded()
{
return !int1;