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EVNMatrixLED

EVNMatrixLED#

This class provides the following features and functionalities for our LED Matrix Standard Peripheral (HT16K33/VK16K33 IC):

  • Controllable 8-by-8 matrix of red LEDs

  • 16 adjustable levels of display brightness

Note

This class does I2C port selection automatically, so users do not need to call setPort() using their EVNAlpha objects.

Wiring (I2C)#

Host

Peripheral

Description

SCL

C

I2C Serial Clock

SDA

D

I2C Serial Data

GND

Ground (0V)

3V3

3.3V Power

Constructor#

class EVNMatrixLED(uint8_t port)#
Parameters

port – I2C port the sensor is connected to (1-16)

Functions#

bool begin()

Initializes display. Call this function before using the other functions.

Returns

Boolean indicating whether the sensor was successfully initialized. If false is returned, all other functions may fail.

Set Functions#

void setDisplayMode(mode mode)

Set mode of display (off, on, or blinking at given frequency)

Parameters

mode – Mode to run display in

  • EVNSevenSegmentLED::mode::OFF (Off)

  • EVNSevenSegmentLED::mode::ON (On)

  • EVNSevenSegmentLED::mode::BLINK_HZ_0_5 (Blinking at 0.5Hz)

  • EVNSevenSegmentLED::mode::BLINK_HZ_1 (Blinking at 1Hz)

  • EVNSevenSegmentLED::mode::BLINK_HZ_2 (Blinking at 2Hz)

void setBrightness(uint8_t brightness)

Set brightness level of display (1-16)

Parameters

brightness – Brightness level from 1 to 16

void setSwapXY(bool enable)

When enabled, swaps X and Y axes (e.g. the pixel at X = 0, Y = 7 becomes X = 7, Y = 0)

Parameters

enable – Boolean indicating whether X and Y axes should be swapped

void setInvertY(bool enable)

When enabled, inverts order of Y axis (e.g. when set to true, the row Y = 0 becomes X = 7)

Parameters

enable – Boolean indicating whether Y axis should be inverted

void setInvertX(bool enable)

When enabled, inverts order of X axis (e.g. when set to true, the column X = 0 becomes X = 7)

Parameters

enable – Boolean indicating whether X axis should be inverted

Get Functions#

EVNMatrixLED::mode getDisplayMode()

Get mode of display (off, on, or blinking at given frequency)

Parameters

mode – Mode that display is set to

  • EVNMatrixLED::mode::OFF (Off)

  • EVNMatrixLED::mode::ON (On)

  • EVNMatrixLED::mode::BLINK_HZ_0_5 (Blinking at 0.5Hz)

  • EVNMatrixLED::mode::BLINK_HZ_1 (Blinking at 1Hz)

  • EVNMatrixLED::mode::BLINK_HZ_2 (Blinking at 2Hz)

uint8_t getBrightness()

Get brightness level of display (1-16)

Parameters

brightness – Brightness level from 1 to 16

bool getSwapXY()
Returns

Whether X and Y axes are swapped

bool getInvertY()
Returns

Whether Y axis is inverted

bool getInvertX()
Returns

Whether X axis is inverted

Display Functions#

void writeOne(uint8_t x, uint8_t y, bool on = true, bool show = true)

Set one LED at given XY coordinate to given state on. If show is true, write buffer to display.

Parameters

  • x – X-coordinate (or column) of pixel

  • y – Y-coordinate (or row) of pixel

  • on – State of LED to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearOne(uint8_t x, uint8_t y, bool show = true)

Set one LED at given XY coordinate to be turned off. If show is true, write buffer to display.

Same as clearOne() but specified pixels are turned off and the on input field is removed.

Parameters

  • x – X-coordinate (or column) of pixel

  • y – Y-coordinate (or row) of pixel

  • show – Whether to write buffer to matrix. Defaults to true

void writeVLine(uint8_t x, uint8_t start_y, uint8_t end_y, bool on = true, bool show = true)

Set vertical line of LEDs with given X-coordinate and within given range of Y-coordinates to given state on. If show is true, write buffer to display.

Parameters

  • x – X-coordinate (or column) of line

  • start_y – start Y-coordinate (or row) of line

  • end_y – ending Y-coordinate (or row) of line

  • on – State of LEDs to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearVLine(uint8_t x, uint8_t start_row, uint8_t end_row, bool show = true)

Set vertical line of LEDs with given X-coordinate and within given range of Y-coordinates to be turned off. If show is true, write buffer to display.

Same as writeVLine() but specified pixels are turned off and the on input field is removed.

Parameters

  • x – X-coordinate (or column) of line

  • start_y – start Y-coordinate (or row) of line

  • end_y – ending Y-coordinate (or row) of line

  • show – Whether to write buffer to matrix. Defaults to true

void writeHLine(uint8_t y, uint8_t start_x, uint8_t end_x, bool on = true, bool show = true)

Set horizontal line of LEDs with given Y-coordinate and within given range of X-coordinates to given state on. If show is true, write buffer to display.

Parameters

  • y – Y-coordinate (or row) of line

  • start_x – start X-coordinate (or column) of line

  • end_x – ending X-coordinate (or column) of line

  • on – State of LEDs to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearHLine(uint8_t y, uint8_t start_x, uint8_t end_x, bool on = true, bool show = true)

Set horizontal line of LEDs with given Y-coordinate and within given range of X-coordinates to be turned off. If show is true, write buffer to display.

Same as writeHLine() but specified pixels are turned off and the on input field is removed.

Parameters

  • y – Y-coordinate (or row) of line

  • start_x – start X-coordinate (or column) of line

  • end_x – ending X-coordinate (or column) of line

  • show – Whether to write buffer to matrix. Defaults to true

void writeY(uint8_t y, bool on = true, bool show = true)

Set entire row of LEDs with given Y-coordinate to given state on. If show is true, write buffer to display.

Parameters

  • y – Y-coordinate (or row) of line

  • on – State of LEDs to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearY(uint8_t y, bool show = true)

Set entire row of LEDs with given Y-coordinate to be turned off. If show is true, write buffer to display.

Same as writeRow() but specified pixels are turned off and the on input field is removed.

Parameters

  • y – Y-coordinate (or row) of line

  • show – Whether to write buffer to matrix. Defaults to true

void writeX(uint8_t x, bool on = true, bool show = true)

Set entire column of LEDs with given X-coordinate to given state on. If show is true, write buffer to display.

Parameters

  • x – X-coordinate (or column) of line

  • on – State of LEDs to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearX(uint8_t x, bool show = true)

Set entire column of LEDs with given X-coordinate to be turned off. If show is true, write buffer to display.

Same as writeX() but specified pixels are turned off and the on input field is removed.

Parameters

  • x – X-coordinate (or column) of line

  • show – Whether to write buffer to matrix. Defaults to true

void clearRectangle(uint8_t start_x, uint8_t end_x, uint8_t start_y, uint8_t end_y, bool on = true, bool show = true)

Set rectanglular region of LEDs within given range of X and Y coordinates to given state on. If show is true, write buffer to display.

Parameters

  • start_x – start X-coordinate (leftmost column) of region

  • end_x – ending X-coordinate (rightmost column) of region

  • start_y – start Y-coordinate (top column) of region

  • end_y – ending Y-coordinate (bottom column) of region

  • on – State of LEDs to be set in buffer (true means on). Defaults to true

  • show – Whether to write buffer to matrix. Defaults to true

void clearRectangle(uint8_t start_x, uint8_t end_x, uint8_t start_y, uint8_t end_y, bool show = true)

Set rectanglular region of LEDs within given range of X and Y coordinates to be turned off. If show is true, write buffer to display.

Same as writeRectangle() but specified pixels are turned off and the on input field is removed.

Parameters

  • start_x – start X-coordinate (leftmost column) of region

  • end_x – ending X-coordinate (rightmost column) of region

  • start_y – start Y-coordinate (top column) of region

  • end_y – ending Y-coordinate (bottom column) of region

  • show – Whether to write buffer to matrix. Defaults to true

void writeAll(bool show = true)

Set all LEDs to be turned on in buffer. If show is true, write buffer to display.

Parameters

show – Whether to write buffer to matrix. Defaults to true

void clearAll(bool show = true)

Set all LEDs to be turned off in buffer. If show is true, write buffer to display.

Parameters

show – Whether to write buffer to matrix. Defaults to true

void update()

Write buffer to display

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