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61 lines
1.5 KiB
61 lines
1.5 KiB
/* |
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* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st> |
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* SPI Master library for arduino. |
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* |
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* This file is free software; you can redistribute it and/or modify |
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* it under the terms of either the GNU General Public License version 2 |
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* or the GNU Lesser General Public License version 2.1, both as |
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* published by the Free Software Foundation. |
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*/ |
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#include "pins_arduino.h" |
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#include "SPI.h" |
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SPIClass SPI; |
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void SPIClass::begin() { |
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// Set direction register for SCK and MOSI pin. |
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// MISO pin automatically overrides to INPUT. |
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// When the SS pin is set as OUTPUT, it can be used as |
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// a general purpose output port (it doesn't influence |
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// SPI operations). |
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pinMode(SCK, OUTPUT); |
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pinMode(MOSI, OUTPUT); |
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pinMode(SS, OUTPUT); |
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digitalWrite(SCK, LOW); |
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digitalWrite(MOSI, LOW); |
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digitalWrite(SS, HIGH); |
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// Warning: if the SS pin ever becomes a LOW INPUT then SPI |
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// automatically switches to Slave, so the data direction of |
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// the SS pin MUST be kept as OUTPUT. |
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SPCR |= _BV(MSTR); |
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SPCR |= _BV(SPE); |
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} |
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void SPIClass::end() { |
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SPCR &= ~_BV(SPE); |
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} |
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void SPIClass::setBitOrder(uint8_t bitOrder) |
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{ |
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if(bitOrder == LSBFIRST) { |
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SPCR |= _BV(DORD); |
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} else { |
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SPCR &= ~(_BV(DORD)); |
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} |
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} |
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void SPIClass::setDataMode(uint8_t mode) |
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{ |
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SPCR = (SPCR & ~SPI_MODE_MASK) | mode; |
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} |
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void SPIClass::setClockDivider(uint8_t rate) |
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{ |
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SPCR = (SPCR & ~SPI_CLOCK_MASK) | (rate & SPI_CLOCK_MASK); |
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SPSR = (SPSR & ~SPI_2XCLOCK_MASK) | ((rate >> 2) & SPI_2XCLOCK_MASK); |
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} |
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