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Code Issues Releases Activity

Use SPI transactions and SPISettings in SD library

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This commit is contained in:
PaulStoffregen 2014-08-01 12:19:51 -07:00
parent a0f5a2ee4c
commit f7a565de1a
1 changed files with 22 additions and 19 deletions
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41
libraries/SD/src/utility/Sd2Card.cpp
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@ -24,6 +24,7 @@
#ifndef SOFTWARE_SPI
#ifdef USE_SPI_LIB
#include <SPI.h>
static SPISettings settings;
#endif
// functions for hardware SPI
/** Send a byte to the card */
@ -158,9 +159,15 @@ uint32_t Sd2Card::cardSize(void) {
//------------------------------------------------------------------------------
void Sd2Card::chipSelectHigh(void) {
digitalWrite(chipSelectPin_, HIGH);
#ifdef USE_SPI_LIB
SPI.endTransaction();
#endif
}
//------------------------------------------------------------------------------
void Sd2Card::chipSelectLow(void) {
#ifdef USE_SPI_LIB
SPI.beginTransaction(settings);
#endif
digitalWrite(chipSelectPin_, LOW);
}
//------------------------------------------------------------------------------
@ -233,7 +240,7 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
// set pin modes
pinMode(chipSelectPin_, OUTPUT);
chipSelectHigh();
digitalWrite(chipSelectPin_, HIGH);
#ifndef USE_SPI_LIB
pinMode(SPI_MISO_PIN, INPUT);
pinMode(SPI_MOSI_PIN, OUTPUT);
@ -251,16 +258,18 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
SPSR &= ~(1 << SPI2X);
#else // USE_SPI_LIB
SPI.begin();
#ifdef SPI_CLOCK_DIV128
SPI.setClockDivider(SPI_CLOCK_DIV128);
#else
SPI.setClockDivider(255);
#endif
settings = SPISettings(250000, MSBFIRST, SPI_MODE0);
#endif // USE_SPI_LIB
#endif // SOFTWARE_SPI
// must supply min of 74 clock cycles with CS high.
#ifdef USE_SPI_LIB
SPI.beginTransaction(settings);
#endif
for (uint8_t i = 0; i < 10; i++) spiSend(0XFF);
#ifdef USE_SPI_LIB
SPI.endTransaction();
#endif
chipSelectLow();
@ -497,21 +506,15 @@ uint8_t Sd2Card::setSckRate(uint8_t sckRateID) {
SPCR |= (sckRateID & 4 ? (1 << SPR1) : 0)
| (sckRateID & 2 ? (1 << SPR0) : 0);
#else // USE_SPI_LIB
int v;
#ifdef SPI_CLOCK_DIV128
switch (sckRateID) {
case 0: v=SPI_CLOCK_DIV2; break;
case 1: v=SPI_CLOCK_DIV4; break;
case 2: v=SPI_CLOCK_DIV8; break;
case 3: v=SPI_CLOCK_DIV16; break;
case 4: v=SPI_CLOCK_DIV32; break;
case 5: v=SPI_CLOCK_DIV64; break;
case 6: v=SPI_CLOCK_DIV128; break;
case 0: settings = SPISettings(25000000, MSBFIRST, SPI_MODE0); break;
case 1: settings = SPISettings(4000000, MSBFIRST, SPI_MODE0); break;
case 2: settings = SPISettings(2000000, MSBFIRST, SPI_MODE0); break;
case 3: settings = SPISettings(1000000, MSBFIRST, SPI_MODE0); break;
case 4: settings = SPISettings(500000, MSBFIRST, SPI_MODE0); break;
case 5: settings = SPISettings(250000, MSBFIRST, SPI_MODE0); break;
default: settings = SPISettings(125000, MSBFIRST, SPI_MODE0);
}
#else // SPI_CLOCK_DIV128
v = 2 << sckRateID;
#endif // SPI_CLOCK_DIV128
SPI.setClockDivider(v);
#endif // USE_SPI_LIB
return true;
}