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InetrfaceProducts NXP / Mbed 2 deprecated PCA9622_LED8x8_Hello

This is a very simple sample code for the PCA9622_LED8x8 library. arget hardware : "I2C 8x8 LED matrix board" from Switch Science https://www.switch-science.com/catalog/2071/

Dependencies: PCA9622_LED8x8 mbed

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0. What is this?¶

Demo sample code for PCA9622_LED8x8 library.

The PCA9622_LED8x8 is a driver for "I2C 8x8 LED matrix board" from Switch Science". This code will show the wave of the brightness on 8x8 LED array.

Import library PCA9622_LED8x8

Library for "I2C 8x8 LED matrix board" from Switch Science https://www.switch-science.com/catalog/2071/

This animation is made by mbed internal calculation.

/media/uploads/nxp_ip/anm.gif

1. How to use¶

Hardware¶

Need to connect 4 wires only.
3.3V supply, GND, and I²C signal lines (SDA, SCL)
This LED matrix board has 10kΩ pull-up resisters on both SDA and SCL. So user don't nee to put those.

wiring

1.2 Software¶

1.2.1 Before compiling¶

Just import this program and run on mbed.
Before compiling, set the PinName for your mbed.

PCA9622_LED8x8  matrix( p28, p27 );     //  for 40pin type mbed
//PCA9622_LED8x8  matrix( D14, D15 );   //  for Arduino type mbed
//PCA9622_LED8x8  matrix( dp5, dp27 );  //  for mbed LPC1114

This code was tested on mbed LPC1768, mbed LPC11U24, mbed LPC1114FN28, TG-LPC11U35-501, mbed LPC1549, LPCXpresso824-MAX.

1.2.2 Customising¶

Modifying func() function will give different behavior of brightness pattern.

#include "mbed.h"
#include "PCA9622_LED8x8.h"

//  Choose a target platform from next list
PCA9622_LED8x8  matrix( p28, p27 );     //  for 40pin type mbed
//PCA9622_LED8x8  matrix( D14, D15 );   //  for Arduino type mbed
//PCA9622_LED8x8  matrix( dp5, dp27 );  //  for mbed LPC1114

float func( float x, float y, float t );    //  function to make 8x8 image

int main()
{
    float   image[ 8 ][ 8 ];  //  
    int     count   = 0;
    
    matrix.start();

    while(1) {
        
        //  making 8x8 image to "image" array
        for ( int i = 0; i < 8; i++ )
            for ( int j = 0; j < 8; j++ )
                image[ i ][ j ]   = func( i, j, count * 0.2 );

        //  set the image into library internal bufer
        matrix.set_data( image );

        count++;
        wait( 0.05 );
    }
}

float func( float x, float y, float t )
{
//#define     DISPLAY_OFFSET  3.5
#define     DISPLAY_OFFSET  0
#define     SIZE            0.3

    float   s;
    
    x   = (x - DISPLAY_OFFSET) * SIZE;
    y   = (y - DISPLAY_OFFSET) * SIZE;

    s   = cos( powf( x * x + y * y, 0.5 ) - t );
    return ( powf( s, 4.0 ) );
}

2. Reference¶

For more information, please find library page and Components page

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