User frequently reported that the ArduCAM shield doesn’t work with DUE board, and it is now a known issue.
We figured out that in the Due board the default SD library speed is much faster than ArduCAM shield. The current ArduCAM shield SPI timing only supports less than 10Mbps. So if you want to work ArduCAM and DUE board together, the SPI should be configured with the lower speed.
To work around this issue, you have to modify the SD library below.
1. Please add the last line to \libraries\SD\utility\Sd2Card.h like follows.
/** Set SCK to max rate of F_CPU/2. See Sd2Card::setSckRate(). */
uint8_t const SPI_FULL_SPEED = 0;
/** Set SCK rate to F_CPU/4. See Sd2Card::setSckRate(). */
uint8_t const SPI_HALF_SPEED = 1;
/** Set SCK rate to F_CPU/8. Sd2Card::setSckRate(). */
uint8_t const SPI_QUARTER_SPEED = 2;
uint8_t const SPI_ARDUCAM_SPEED = 3;
2. Please change the SDClass::begin() function in the \libraries\SD\SD.cpp file like follows:
boolean SDClass::begin(uint8_t csPin) {
/*
Performs the initialisation required by the sdfatlib library.
Return true if initialization succeeds, false otherwise.
*/
//return card.init( SPI_FULL_SPEED, csPin) &&
//return card.init(SPI_HALF_SPEED, csPin) &&
//return card.init(SPI_QUARTER_SPEED, csPin) &&
return card.init(SPI_ARDUCAM_SPEED, csPin) &&
volume.init(card) &&
root.openRoot(volume);
}
