Unit RPISENSEHAT
From Ultibo.org
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Description
Raspberry Pi Sense HAT Driver unit
The Sense HAT 8x8 LED matrix is presented in Ultibo as an 8x8 pixel framebuffer. This allows full access to the display at both the individual pixel level and also using the higher level console functions to display text and graphics on the matrix.
The framebuffer device supports rotation around the full 360 degrees by supplying the required rotation value in the framebuffer properties when calling FramebufferAllocate() or by calling the Sense HAT specific function RPiSenseFramebufferSetRotation().
As per the official Python libraries, the default rotation (FRAMEBUFFER_ROTATION_0) gives correct viewing when the HDMI port is facing downwards.
The Sense HAT joystick appears as a keyboard device and the pressed buttons are received as key presses that represent the Left, Right, Up, Down and Enter keys.
Constants
RPiSenseHat specific constants
RPISENSE_* RPISENSE_SIGNATURE = $EAEBECED;
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Framebuffer
RPISENSE_FRAMEBUFFER_* RPISENSE_FRAMEBUFFER_DESCRIPTION = 'Raspberry Pi Sense HAT Framebuffer';
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Description of RPiSense framebuffer device |
RPISENSE_PHYSICAL_WIDTH = 8;
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RPISENSE_PHYSICAL_HEIGHT = 8;
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Joystick
RPISENSE_JOYSTICK_* RPISENSE_JOYSTICK_DESCRIPTION = 'Raspberry Pi Sense HAT Joystick';
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Description of RPiSense joystick device |
RPISENSE_JOYSTICK_KEYMAP:array[0..4] of Word = (
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SCAN_CODE_DOWN_ARROW,
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SCAN_CODE_RIGHT_ARROW,
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SCAN_CODE_UP_ARROW,
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SCAN_CODE_ENTER,
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SCAN_CODE_LEFT_ARROW
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RPiSenseHat register value
RPISENSE_FB* RPISENSE_FB = $00;
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RPISENSE_WAI = $F0;
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RPISENSE_VER = $F1;
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RPISENSE_KEYS = $F2;
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RPISENSE_EE_WP = $F3;
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RPiSenseHat gamma reset value
RPISENSE_GAMMA_* RPISENSE_GAMMA_VALUES_DEFAULT = 0;
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RPISENSE_GAMMA_VALUES_LOW = 1;
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RPISENSE_GAMMA_VALUES_USER = 2;
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Type definitions
RPi sense
PRPiSense = ^TRPiSense;
TRPiSense = record
Signature:LongWord;
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Signature for entry validation |
I2C:PI2CDevice;
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I2C device |
GPIO:PGPIODevice;
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GPIO device |
Framebuffer:PFramebufferDevice;
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Framebuffer device |
Joystick:PKeyboardDevice;
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Joystick (Keyboard) device |
RPi sense gamma
PRPiSenseGamma = ^TRPiSenseGamma;
TRPiSenseGamma = array[0..31] of Byte;
RPi sense framebuffer
PRPiSenseFramebuffer = ^TRPiSenseFramebuffer;
TRPiSenseFramebuffer = record
| Framebuffer Properties | |
Framebuffer:TFramebufferDevice;
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| RPiSense Properties | |
I2C:PI2CDevice;
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The I2C device the device is connected to |
Width:LongWord;
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Framebuffer Width in Pixels (Virtual) |
Height:LongWord;
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Framebuffer Height in Pixels (Virtual) |
Rotation:LongWord;
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Framebuffer Rotation (eg FRAMEBUFFER_ROTATION_180) |
DirtyY1:LongWord;
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First line of dirty region (or Height - 1 if none dirty) |
DirtyY2:LongWord;
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Last line of dirty region (or 0 if none dirty) |
Ready:LongBool;
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If True timer should be enabled during Mark operation |
Blank:LongBool;
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If True then display is currently blanked |
Lock:TMutexHandle;
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Lock for dirty region redraw |
Timer:TTimerHandle;
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Handle for dirty region redraw timer |
FrameRate:LongWord;
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Frame rate for display refresh (in Frames Per Second) |
Gamma:TRPiSenseGamma;
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Current gamma values |
GammaUser:TRPiSenseGamma;
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User gamma values |
PixelData:array[0..63] of Word;
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Pixel data for framebuffer update |
BlockData:array[0..192] of Byte;
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Block data for display update |
RPi sense joystick
PRPiSenseJoystick = ^TRPiSenseJoystick;
TRPiSenseJoystick = record
| Keyboard Properties | |
Keyboard:TKeyboardDevice;
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| RPiSense Properties | |
I2C:PI2CDevice;
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The I2C device the device is connected to |
GPIO:PGPIODevice;
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The GPIO device the device is connected to |
Pin:LongWord;
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The GPIO pin used to signal joystick events (GPIO_PIN_23) |
Trigger:LongWord;
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The GPIO trigger to detect joystick events (GPIO_TRIGGER_RISING) |
PreviousKeys:LongInt;
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The keys pressed on the last GPIO event callback |
| Statistics Properties | |
CallbackCount:LongWord;
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Number of callback requests received by the device |
Public variables
RPiSenseHat specific variables
RPISENSE_I2C_DEVICE:String = 'I2C0';
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RPISENSE_GPIO_DEVICE:String = 'GPIO0';
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RPISENSE_FRAMEBUFFER_ROTATION:LongWord = FRAMEBUFFER_ROTATION_0;
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RPISENSE_FRAMEBUFFER_WIDTH:LongWord = RPISENSE_PHYSICAL_WIDTH;
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RPISENSE_FRAMEBUFFER_HEIGHT:LongWord = RPISENSE_PHYSICAL_HEIGHT;
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RPISENSE_I2C_ADDRESS:Word = $46;
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RPISENSE_LSM9DS1_MAGN_ADDRESS:Word = $1C;
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RPISENSE_LSM9DS1_ACCEL_ADDRESS:Word = $6A;
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RPISENSE_LPS25H_PRESS_ADDRESS:Word = $5C;
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RPISENSE_HTS221_HUMID_ADDRESS:Word = $5F;
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Function declarations
Initialization functions
procedure RPiSenseInit;
Description: Initialize the RPiSenseHat unit and parameters
| Note | Called only during system startup |
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function RPiSenseStart(const I2CDevice,GPIODevice:String; Rotation,Width,Height:LongWord):THandle;
Description: Start the RPiSenseHat driver and register the Framebuffer and Joystick devices
| I2C | The name of the I2C device that the Sense HAT is connected to |
|---|---|
| GPIO | The name of the GPIO device that the Sense HAT is connected to |
| Rotation | The rotation value of the framebuffer (eg FRAMEBUFFER_ROTATION_180) |
| Width | The width of the framebuffer in pixels (Virtual width only, the Physical width is fixed at 8 pixels) |
| Height | The height of the framebuffer in pixels (Virtual height only, the Physical height is fixed at 8 pixels) |
| Return | The handle of the RPiSenseHat on success or INVALID_HANDLE_VALUE on failure |
| Note | This function will be called during startup if the parameter RPISENSE_AUTOSTART is True |
function RPiSenseStop(Handle:THandle):Boolean;
Description: Stop the RPiSenseHat driver and deregister the Framebuffer and Joystick devices
| Handle | The handle of the RPiSenseHat or INVALID_HANDLE_VALUE for the default |
|---|---|
| Return | True if completed or False on failure |
RPiSenseHat framebuffer functions
function RPiSenseFramebufferCreate(I2C:PI2CDevice; const Name:String; Rotation,Width,Height:LongWord):PFramebufferDevice;
Description: Create, register and allocate a new RPiSenseHat Framebuffer device which can be accessed using the framebuffer API
| I2C | The I2C device that the RPiSenseHat is connected to |
|---|---|
| Name | The text description of this device which will show in the device list (Optional) |
| Rotation | The rotation value of the framebuffer (eg FRAMEBUFFER_ROTATION_180) |
| Width | The width of the framebuffer in pixels (Virtual width only, the Physical width is fixed at 8 pixels) |
| Height | The height of the framebuffer in pixels (Virtual height only, the Physical height is fixed at 8 pixels) |
| Return | Pointer to the new Framebuffer device or nil if the framebuffer device could not be created |
function RPiSenseFramebufferDestroy(Framebuffer:PFramebufferDevice):LongWord;
Description: Release, deregister and destroy an RPiSenseHat Framebuffer device created by this driver}
| Framebuffer | The Framebuffer device to destroy |
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| Return | ERROR_SUCCESS if completed or another error code on failure |
function RPiSenseFramebufferAllocate(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;
Description: Implementation of FramebufferDeviceAllocate API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceAllocate instead. |
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function RPiSenseFramebufferRelease(Framebuffer:PFramebufferDevice):LongWord;
Description: Implementation of FramebufferDeviceRelease API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceRelease instead. |
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function RPiSenseFramebufferBlank(Framebuffer:PFramebufferDevice; Blank:Boolean):LongWord;
Description: Implementation of FramebufferDevicBlank API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDevicBlank instead. |
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function RPiSenseFramebufferMark(Framebuffer:PFramebufferDevice; X,Y,Width,Height,Flags:LongWord):LongWord;
Description: Implementation of FramebufferDeviceMark API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceMark instead.
Marks full lines only, X and Width are ignored for RPiSenseHat Framebuffer |
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function RPiSenseFramebufferCommit(Framebuffer:PFramebufferDevice; Address,Size,Flags:LongWord):LongWord;
Description: Implementation of FramebufferDeviceCommit API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceCommit instead. |
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function RPiSenseFramebufferSetOffset(Framebuffer:PFramebufferDevice; X,Y:LongWord; Pan:Boolean):LongWord;
Description: Implementation of FramebufferDeviceSetOffset API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceSetOffset instead. |
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function RPiSenseFramebufferSetProperties(Framebuffer:PFramebufferDevice; Properties:PFramebufferProperties):LongWord;
Description: Implementation of FramebufferDeviceSetProperties API for RPiSenseHat Framebuffer
| Note | Not intended to be called directly by applications, use FramebufferDeviceSetProperties instead. |
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function RPiSenseFramebufferGetGamma(Framebuffer:PFramebufferDevice; var Gamma:TRPiSenseGamma):LongWord;
Description: Get the current gamma values from the RPiSenseHat framebuffer
| Framebuffer | The Framebuffer device to get from |
|---|---|
| Gamma | An array of gamma values returned on completion |
| Return | ERROR_SUCCESS if completed or another error code on failure |
function RPiSenseFramebufferSetGamma(Framebuffer:PFramebufferDevice; const Gamma:TRPiSenseGamma):LongWord;
Description: Set the current gamma values for the RPiSenseHat framebuffer
| Framebuffer | The Framebuffer device to set for |
|---|---|
| Gamma | An array of gamma values to set |
| Return | ERROR_SUCCESS if completed or another error code on failure |
function RPiSenseFramebufferResetGamma(Framebuffer:PFramebufferDevice; Value:LongWord):LongWord;
Description: Reset the current gamma values for the RPiSenseHat framebuffer to Default, Low or User
| Framebuffer | The Framebuffer device to set for |
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| Value | The gamma values to set (0 = Default / 1 = Low / 2 = User) |
| Return | ERROR_SUCCESS if completed or another error code on failure |
function RPiSenseFramebufferSetRotation(Framebuffer:PFramebufferDevice; Rotation:LongWord):LongWord;
Description: To be documented
| Note | None documented |
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procedure RPiSenseFramebufferUpdateDisplay(Framebuffer:PRPiSenseFramebuffer);
Description: Timer function for RPiSenseHat framebuffer dirty region redraw
| Note | Not intended to be called directly by applications |
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RPiSenseHat joystick functions
function RPiSenseJoystickCreate(I2C:PI2CDevice; GPIO:PGPIODevice; const Name:String):PKeyboardDevice;
Description: Create, register and attach a new RPiSenseHat Joystick device which can be accessed using the keyboard API
| I2C | The I2C device that the RPiSenseHat is connected to |
|---|---|
| GPIO | The GPIO device that the RPiSenseHat is connected to |
| Name | The text description of this device which will show in the device list (Optional) |
| Return | Pointer to the new Joystick (Keyboard) device or nil if the device could not be created |
function RPiSenseJoystickDestroy(Joystick:PKeyboardDevice):LongWord;
Description: Detach, deregister and destroy a RPiSenseHat Joystick device created by this driver
| Joystick | The Joystick (Keyboard) device to destroy |
|---|---|
| Return | ERROR_SUCCESS if completed or another error code on failure |
procedure RPiSenseJoystickCallback(Joystick:PRPiSenseJoystick; Pin,Trigger:LongWord);
Description: Callback function for the RPiSenseHat Joystick device, called on a worker thread when the registered GPIO event is triggered by a rising edge on the specified pin
| Note | Not intended to be called directly by applications |
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RPiSenseHat helper functions
function RPiSenseRegRead(I2C:PI2CDevice; Address:Word; Reg:Byte):LongInt;
Description: Read a byte from an RPiSenseHat register
| I2C | The I2C device the RPiSenseHat is connected to |
|---|---|
| Address | The I2C address of the RPiSenseHat |
| Reg | The register to read |
| Return | The register value on success or -1 on failure |
function RPiSenseBlockWrite(I2C:PI2CDevice; Address:Word; Data:PByte; Size:Integer):LongWord;
Description: Write a block of data to the RPiSenseHat
| I2C | The I2C device the RPiSenseHat is connected to |
|---|---|
| Address | The I2C address of the RPiSenseHat |
| Data | Pointer to the data block to be written |
| Size | Size of the data block in bytes |
| Return | ERROR_SUCCESS if completed or another error code on failure |
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