exploringBB::SevenSegmentDisplay Class Reference

A class that allows you to drive an array of 7 segment displays using an array of 74XX595 ICs. More...

#include <SevenSegmentDisplay.h>

Public Member Functions
	SevenSegmentDisplay (SPIDevice *device, int numberSegments)
virtual int	write (int number)
virtual int	write (float number, int places)
virtual int	setNumberBase (int base)
virtual int	getNumberBase ()
virtual int	getNumberSegments ()
virtual void	setCommonAnode (bool isCommonAnode)
virtual	~SevenSegmentDisplay ()

Detailed Description

A class that allows you to drive an array of 7 segment displays using an array of 74XX595 ICs.

Constructor & Destructor Documentation

exploringBB::SevenSegmentDisplay::SevenSegmentDisplay	(	SPIDevice *	device,
		int	numberSegments
	)

The constructor for the 7-segment display that defines the number of segments.

Parameters

device	The pointer to the SPI device bus
numberSegments	The number of 7-segment modules attached to the bus

                                                                              {
        this->spidevice = device;
        this->numberSegments = numberSegments;
        this->numberBase = 10; //decimal by default
        this->isCommonAnode = false;
}

exploringBB::SevenSegmentDisplay::~SevenSegmentDisplay ( )

virtual

                                          {
        this->spidevice->close();
}

Member Function Documentation

virtual int exploringBB::SevenSegmentDisplay::getNumberBase ( )

inlinevirtual

{ return this->numberBase; }

virtual int exploringBB::SevenSegmentDisplay::getNumberSegments ( )

inlinevirtual

{ return this->numberSegments; }

virtual void exploringBB::SevenSegmentDisplay::setCommonAnode ( bool  isCommonAnode )

inlinevirtual

{ this->isCommonAnode = isCommonAnode; }

int exploringBB::SevenSegmentDisplay::setNumberBase ( int  base )

virtual

                                              {
        if (base>16 || base<2) return -1;
        return (this->numberBase = base);
}

int exploringBB::SevenSegmentDisplay::write ( int  number )

virtual

                                        {
    // going to send one character for each segment
        unsigned char output[this->numberSegments];
        // output least-significant digit and divide by base
    for(int i=0; i<this->numberSegments; i++){
       output[i] = this->symbols[number%this->numberBase];
       if(this->isCommonAnode) output[i]=~output[i]; //invert the bits for common anode
       number = number/this->numberBase;
    }
    this->spidevice->write(output, this->numberSegments);
        return 0;
}

int exploringBB::SevenSegmentDisplay::write ( float  number, int  places  )

virtual

                                                      {
        // if the number of places is greater than the number of segments -1, stop.
        if (places>(this->numberSegments-1)) return -1;
        // can display non-decimal floats
        int intNumber = (int) number;
        if (places>0) intNumber = (int)(number * places * this->numberBase);
    // going to send one character for each segment
        unsigned char output[this->numberSegments];
        // output least-significant digit and divide by base
    for(int i=0; i<this->numberSegments; i++){
       output[i] = this->symbols[intNumber%this->numberBase];
       if(i==places) output[i] = output[i] | 0b10000000; // turn on "decimal point"
       if(this->isCommonAnode) output[i]=~output[i]; //invert the bits for common anode
       intNumber = intNumber/this->numberBase;
    }
    this->spidevice->write(output, this->numberSegments);
        return 0;
}

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The documentation for this class was generated from the following files:

• /home/molloyd/exploringBB/library/display/SevenSegmentDisplay.h
• /home/molloyd/exploringBB/library/display/SevenSegmentDisplay.cpp