//------------------------------------------------------------------------------
// send command to card
uint8_t SdReader::cardCommand(uint8_t cmd, uint32_t arg) {
//Serial.print("cardCommand, cmd="); Serial.print(cmd, DEC); Serial.print(", arg="); Serial.println(arg, DEC);
uint8_t r1;
// end read if in partialBlockRead mode
readEnd();
// select card
spiSSLow();
// wait up to 300 ms if busy
waitNotBusy(300);
// send command
spiSend(cmd | 0x40);
// send argument
for (int8_t s = 24; s >= 0; s -= 8) spiSend(arg >> s);
// send CRC
uint8_t crc = 0XFF;
if (cmd == CMD0) crc = 0X95; // correct crc for CMD0 with arg 0
if (cmd == CMD8) crc = 0X87; // correct crc for CMD8 with arg 0X1AA
spiSend(crc);
// wait for response
for (uint8_t retry = 0; ((r1 = spiRec()) & 0X80) && retry != 0XFF; retry++);
return r1;
}
/**
* Initialize a SD flash memory card.
*
* \param[in] slow Set SPI Frequency F_CPU/4 if true else F_CPU/2.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*
*/
uint8_t SdCard::init(uint8_t slow)
{
pinMode(SS, OUTPUT);
spiSSHigh();
pinMode(MOSI, OUTPUT);
pinMode(SCK, OUTPUT);
//Enable SPI, Master, clock rate F_CPU/128
SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR1) | (1 << SPR0);
//must supply min of 74 clock cycles with CS high.
for (uint8_t i = 0; i < 10; i++) spiSend(0XFF);
spiSSLow();
// next line prevent re-init hang by some cards (not sure why this works)
for (uint16_t i = 0; i <= 512; i++) spiRec();
uint8_t r = cardCommand(CMD0, 0);
for (uint16_t retry = 0; r != R1_IDLE_STATE; retry++){
if (retry == 10000) {
error(SD_ERROR_CMD0, r);
return false;
}
r = spiRec();
}
for (uint16_t retry = 0; ; retry++) {
cardCommand(CMD55, 0);
if ((r = cardCommand(ACMD41, 0)) == R1_READY_STATE)break;
if (retry == 1000) {
error(SD_ERROR_ACMD41, r);
return false;
}
}
// set SPI frequency
SPCR &= ~((1 << SPR1) | (1 << SPR0)); // F_CPU/4
if (!slow) SPSR |= (1 << SPI2X); // Doubled Clock Frequency to F_CPU/2
spiSSHigh();
return true;
}
//------------------------------------------------------------------------------
// send command to card
uint8_t sdCardCommand(uint8_t cmd, uint32_t arg) {
uint8_t r1;
uint8_t retry;
signed char s;
// end read if in partialBlockRead mode
sdReadEnd();
// select card
spiSSLow();
// wait up to 300 ms if busy
sdWaitNotBusy(300);
// send command
spiSend(cmd | 0x40);
// send argument
for (s = 24; s >= 0; s -= 8) spiSend(arg >> s);
// send CRC
uint8_t crc = 0XFF;
if (cmd == CMD0) crc = 0X95; // correct crc for CMD0 with arg 0
if (cmd == CMD8) crc = 0X87; // correct crc for CMD8 with arg 0X1AA
spiSend(crc);
// wait for response
for (retry = 0; ((r1 = spiRec()) & 0X80) && retry != 0XFF; retry++);
return r1;
}
//------------------------------------------------------------------------------
static uint8_t cardCommand(uint8_t cmd, uint32_t arg)
{
uint8_t r1;
// some cards need extra clocks after transaction to go to ready state
// easiest to put extra clocks before next transaction
spiSSLow();
spiRec();
spiSend(cmd | 0x40);
for (int8_t s = 24; s >= 0; s -= 8) spiSend(arg >> s);
spiSend(cmd == CMD0 ? 0x95 : 0XFF);//must send valid CRC for CMD0
//wait for not busy
for (uint8_t retry = 0; (r1 = spiRec()) == 0xFF && retry != 0XFF; retry++);
return r1;
}
/**
* Initialize a SD flash memory card.
*
* \param[in] slow If \a slow is false (zero) the SPI bus will
* be initialize at a speed of 8 Mhz. If \a slow is true (nonzero)
* the SPI bus will be initialize a speed of 4 Mhz. This may be helpful
* for some SD cards with Version 1.0 of the Adafruit Wave Shield.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*
*/
uint8_t SdReader::init(uint8_t slow) {
uint8_t ocr[4];
uint8_t r;
pinMode(SS, OUTPUT);
digitalWrite(SS, HIGH);
pinMode(MOSI, OUTPUT);
pinMode(MISO_PIN, INPUT);
pinMode(SCK, OUTPUT);
#if SPI_INIT_SLOW
// Enable SPI, Master, clock rate f_osc/128
SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR1) | (1 << SPR0);
#else // SPI_INIT_SLOW
// Enable SPI, Master, clock rate f_osc/64
SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR1);
#endif // SPI_INIT_SLOW
// must supply min of 74 clock cycles with CS high.
for (uint8_t i = 0; i < 10; i++) spiSend(0XFF);
// next two lines prevent re-init hang by cards that were in partial read
spiSSLow();
for (uint16_t i = 0; i <= 512; i++) spiRec();
// command to go idle in SPI mode
for (uint8_t retry = 0; ; retry++) {
if ((r = cardCommand(CMD0, 0)) == R1_IDLE_STATE) break;
if (retry == 10) {
error(SD_CARD_ERROR_CMD0, r);
return false;
}
}
// check SD version
r = cardCommand(CMD8, 0x1AA);
if (r == R1_IDLE_STATE) {
for(uint8_t i = 0; i < 4; i++) {
r = spiRec();
}
if (r != 0XAA) {
error(SD_CARD_ERROR_CMD8_ECHO, r);
return false;
}
type(SD_CARD_TYPE_SD2);
}
else if (r & R1_ILLEGAL_COMMAND) {
type(SD_CARD_TYPE_SD1);
}
else {
error(SD_CARD_ERROR_CMD8, r);
}
// initialize card and send host supports SDHC if SD2
for (uint16_t t0 = millis();;) {
cardCommand(CMD55, 0);
r = cardCommand(ACMD41, type() == SD_CARD_TYPE_SD2 ? 0X40000000 : 0);
if (r == R1_READY_STATE) break;
// timeout after 2 seconds
if (((uint16_t)millis() - t0) > 2000) {
error(SD_CARD_ERROR_ACMD41);
return false;
}
}
// if SD2 read OCR register to check for SDHC card
if (type() == SD_CARD_TYPE_SD2) {
if(cardCommand(CMD58, 0)) {
error(SD_CARD_ERROR_CMD58);
return false;
}
if ((spiRec() & 0XC0) == 0XC0) type(SD_CARD_TYPE_SDHC);
// discard rest of ocr
for (uint8_t i = 0; i < 3; i++) spiRec();
}
// use max SPI frequency unless slow is true
SPCR &= ~((1 << SPR1) | (1 << SPR0)); // f_OSC/4
if (!slow) SPSR |= (1 << SPI2X); // Doubled Clock Frequency: f_OSC/2
spiSSHigh();
return true;
}
/**
* Initialize a SD flash memory card.
*
* \param[in] slow Set SPI Frequency F_CPU/4 if true else F_CPU/2.
*
* \return The value one, true, is returned for success and
* the value zero, false, is returned for failure.
*/
uint8_t Sd2Card::init(uint8_t slow)
{
uint8_t r;
errorCode_ = inBlock_ = partialBlockRead_ = type_ = 0;
// set pin modes
spiSSOutputMode();
spiSSHigh();
spiMISOInputMode();
spiMOSIOutputMode();
spiSCKOutputMode();
#ifndef SOFTWARE_SPI
//Enable SPI, Master, clock rate f_osc/128
SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR1) | (1 << SPR0);
#endif //SOFTWARE_SPI
//must supply min of 74 clock cycles with CS high.
for (uint8_t i = 0; i < 10; i++) spiSend(0XFF);
// next two lines prevent re-init hang by cards that were in partial read
spiSSLow();
for (uint16_t i = 0; i <= 512; i++) spiRec();
// command to go idle in SPI mode
for (uint8_t retry = 0; ; retry++) {
if ((r = cardCommand(CMD0, 0)) == R1_IDLE_STATE) break;
if (retry == 10) {
error(SD_CARD_ERROR_CMD0, r);
return false;
}
}
// check SD version
if ((cardCommand(CMD8, 0x1AA) & R1_ILLEGAL_COMMAND)) {
type(SD_CARD_TYPE_SD1);
}
else {
// only need last byte of r7 response
for(uint8_t i = 0; i < 4; i++) r = spiRec();
if (r != 0XAA) {
error(SD_CARD_ERROR_CMD8, r);
return false;
}
type(SD_CARD_TYPE_SD2);
}
// initialize card and send host supports SDHC if SD2
for (uint16_t t0 = millis();;) {
r = cardAcmd(ACMD41, type() == SD_CARD_TYPE_SD2 ? 0X40000000 : 0);
if (r == R1_READY_STATE) break;
// timeout after 2 seconds
if (((uint16_t)millis() - t0) > 2000) {
error(SD_CARD_ERROR_ACMD41);
return false;
}
}
// if SD2 read OCR register to check for SDHC card
if (type() == SD_CARD_TYPE_SD2) {
if(cardCommand(CMD58, 0)) {
error(SD_CARD_ERROR_CMD58);
return false;
}
if ((spiRec() & 0XC0) == 0XC0) type(SD_CARD_TYPE_SDHC);
// discard rest of ocr
for (uint8_t i = 0; i < 3; i++) spiRec();
}
#ifndef SOFTWARE_SPI
// set SPI frequency to f_OSC/4
SPCR &= ~((1 << SPR1) | (1 << SPR0));
// if !slow set SPI frequency to f_OSC/2
if (!slow) SPSR |= (1 << SPI2X);
#endif // SOFTWARE_SPI
spiSSHigh();
return true;
}
