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spi_bb.cpp
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spi_bb.cpp
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/*
* spi_bb.cpp
*
* Created: 12/1/2017
* Author: Troy
*/
#include "spi_bb.h"
void nop(); // default delay function;
Spi_bb::Spi_bb( Gpio clock, Gpio mosi, Gpio miso, Gpio slave_select, bool cpol, bool cpha, void(*FN_CLOCK_DELAY)() )
:sclk_(clock)
,mosi_(mosi)
,miso_(miso)
,ss_(slave_select)
,cpha_(cpha)
,cpol_(cpol)
,FN_CLOCK_DELAY_(FN_CLOCK_DELAY)
{
if(FN_CLOCK_DELAY_ == nullptr )
FN_CLOCK_DELAY_ = nop;
this->deselect_slave();
//set clock line to the correct idle state
sclk_.set(cpol_);
}
//
//
//tx a single byte, returns byte received
char Spi_bb::tx( char data )
{
char rx_val = 0;
if( cpha_)
{
for(int inx = 7; inx > -1 ; --inx )
{
mosi_.set( (data >> inx) & 1);
rx_val += miso_.value() << inx;
this->FN_CLOCK_DELAY_();
sclk_.toggle();
this->FN_CLOCK_DELAY_();
sclk_.toggle();
}
}
else
{
for(int inx = 7; inx > -1 ; --inx )
{
this->FN_CLOCK_DELAY_();
sclk_.toggle();
this->FN_CLOCK_DELAY_();
mosi_.set( (data >> inx) & 1);
rx_val += miso_.value() << inx;
sclk_.toggle();
}
}
return rx_val;
}
//tx_buff and rx_buff many bytes, both buffers must be at as big as size
void Spi_bb::tx( char * const tx_buff, char * rx_buff, int size )
{
for(int inx = 0; inx < size; inx ++)
rx_buff[inx] = this->tx(tx_buff[inx]);
}
//
//
//
void Spi_bb::select_slave()
{
this->ss_.clear();
}
//
//
//
void Spi_bb::deselect_slave()
{
this->ss_.set();
}
//
//
//
void nop()
{
__NOP();
}