#include <Adafruit_SPIDevice.h>
#include <Arduino.h>
//#define DEBUG_SERIAL Serial
/*!
* @brief Create an SPI device with the given CS pin and settins
* @param cspin The arduino pin number to use for chip select
* @param freq The SPI clock frequency to use, defaults to 1MHz
* @param dataOrder The SPI data order to use for bits within each byte, defaults to SPI_BITORDER_MSBFIRST
* @param dataMode The SPI mode to use, defaults to SPI_MODE0
* @param theSPI The SPI bus to use, defaults to &theSPI
*/
Adafruit_SPIDevice::Adafruit_SPIDevice(int8_t cspin, uint32_t freq, BitOrder dataOrder, uint8_t dataMode, SPIClass *theSPI) {
_cs = cspin;
_sck = _mosi = _miso = -1;
_spi = theSPI;
_begun = false;
_spiSetting = new SPISettings(freq, dataOrder, dataMode);
_freq = freq;
_dataOrder = dataOrder;
_dataMode = dataMode;
}
/*!
* @brief Create an SPI device with the given CS pin and settins
* @param cspin The arduino pin number to use for chip select
* @param sckpin The arduino pin number to use for SCK
* @param misopin The arduino pin number to use for MISO, set to -1 if not used
* @param mosipin The arduino pin number to use for MOSI, set to -1 if not used
* @param freq The SPI clock frequency to use, defaults to 1MHz
* @param dataOrder The SPI data order to use for bits within each byte, defaults to SPI_BITORDER_MSBFIRST
* @param dataMode The SPI mode to use, defaults to SPI_MODE0
*/
Adafruit_SPIDevice::Adafruit_SPIDevice(int8_t cspin, int8_t sckpin, int8_t misopin, int8_t mosipin,
uint32_t freq, BitOrder dataOrder, uint8_t dataMode) {
_cs = cspin;
_sck = sckpin;
_miso = misopin;
_mosi = mosipin;
_freq = freq;
_dataOrder = dataOrder;
_dataMode = dataMode;
_begun = false;
_spiSetting = new SPISettings(freq, dataOrder, dataMode);
_spi = NULL;
}
/*!
* @brief Initializes SPI bus and sets CS pin high
* @return Always returns true because there's no way to test success of SPI init
*/
bool Adafruit_SPIDevice::begin(void) {
pinMode(_cs, OUTPUT);
digitalWrite(_cs, HIGH);
if (_spi) { // hardware SPI
_spi->begin();
} else {
pinMode(_sck, OUTPUT);
if (_dataMode==SPI_MODE0) {
digitalWrite(_sck, HIGH);
} else {
digitalWrite(_sck, LOW);
}
if (_mosi != -1) {
pinMode(_mosi, OUTPUT);
digitalWrite(_mosi, HIGH);
}
if (_miso != -1) {
pinMode(_miso, INPUT);
}
}
_begun = true;
return true;
}
/*!
* @brief Transfer (send/receive) one byte over hard/soft SPI
* @param buffer The buffer to send and receive at the same time
* @param len The number of bytes to transfer
*/
void Adafruit_SPIDevice::transfer(uint8_t *buffer, size_t len) {
if (_spi) {
// hardware SPI is easy
_spi->transfer(buffer, len);
return;
}
// for softSPI we'll do it by hand
for (size_t i=0; i<len; i++) {
// software SPI
uint8_t reply = 0;
uint8_t send = buffer[i];
if (_dataOrder == SPI_BITORDER_LSBFIRST) {
// LSB is rare, if it happens we'll just flip the bits around for them
uint8_t temp = 0;
for (uint8_t b=0; b<8; b++) {
temp |= ((send >> b) & 0x1) << (7-b);
}
send = temp;
}
for (int b=7; b>=0; b--) {
reply <<= 1;
if (_dataMode == SPI_MODE0) {
digitalWrite(_sck, LOW);
digitalWrite(_mosi, send & (1<<b));
digitalWrite(_sck, HIGH);
if ((_miso != -1) && digitalRead(_miso)) {
reply |= 1;
}
}
if (_dataMode == SPI_MODE1) {
digitalWrite(_sck, HIGH);
digitalWrite(_mosi, send & (1<<b));
digitalWrite(_sck, LOW);
if ((_miso != -1) && digitalRead(_miso)) {
reply |= 1;
}
}
}
if (_dataOrder == SPI_BITORDER_LSBFIRST) {
// LSB is rare, if it happens we'll just flip the bits around for them
uint8_t temp = 0;
for (uint8_t b=0; b<8; b++) {
temp |= ((reply >> b) & 0x1) << (7-b);
}
reply = temp;
}
buffer[i] = reply;
}
return;
}
/*!
* @brief Transfer (send/receive) one byte over hard/soft SPI
* @param send The byte to send
* @return The byte received while transmitting
*/
uint8_t Adafruit_SPIDevice::transfer(uint8_t send) {
uint8_t data = send;
transfer(&data, 1);
return data;
}
/*!
* @brief Write a buffer or two to the SPI device.
* @param buffer Pointer to buffer of data to write
* @param len Number of bytes from buffer to write
* @param prefix_buffer Pointer to optional array of data to write before buffer.
* @param prefix_len Number of bytes from prefix buffer to write
* @return Always returns true because there's no way to test success of SPI writes
*/
bool Adafruit_SPIDevice::write(uint8_t *buffer, size_t len, uint8_t *prefix_buffer, size_t prefix_len) {
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
digitalWrite(_cs, LOW);
// do the writing
for (size_t i=0; i<prefix_len; i++) {
transfer(prefix_buffer[i]);
}
for (size_t i=0; i<len; i++) {
transfer(buffer[i]);
}
digitalWrite(_cs, HIGH);
if (_spi) {
_spi->endTransaction();
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
if ((prefix_len != 0) && (prefix_buffer != NULL)) {
for (uint16_t i=0; i<prefix_len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(prefix_buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
}
}
for (uint16_t i=0; i<len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
return true;
}
/*!
* @brief Read from SPI into a buffer from the SPI device.
* @param buffer Pointer to buffer of data to read into
* @param len Number of bytes from buffer to read.
* @param sendvalue The 8-bits of data to write when doing the data read, defaults to 0xFF
* @return Always returns true because there's no way to test success of SPI writes
*/
bool Adafruit_SPIDevice::read(uint8_t *buffer, size_t len, uint8_t sendvalue) {
memset(buffer, sendvalue, len); // clear out existing buffer
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
digitalWrite(_cs, LOW);
transfer(buffer, len);
digitalWrite(_cs, HIGH);
if (_spi) {
_spi->endTransaction();
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Read: "));
for (uint16_t i=0; i<len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
return true;
}
/*!
* @brief Write some data, then read some data from SPI into another buffer. The buffers can point to same/overlapping locations. This does not transmit-receive at the same time!
* @param write_buffer Pointer to buffer of data to write from
* @param write_len Number of bytes from buffer to write.
* @param read_buffer Pointer to buffer of data to read into.
* @param read_len Number of bytes from buffer to read.
* @param sendvalue The 8-bits of data to write when doing the data read, defaults to 0xFF
* @return Always returns true because there's no way to test success of SPI writes
*/
bool Adafruit_SPIDevice::write_then_read(uint8_t *write_buffer, size_t write_len, uint8_t *read_buffer, size_t read_len, uint8_t sendvalue) {
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
digitalWrite(_cs, LOW);
// do the writing
for (size_t i=0; i<write_len; i++) {
transfer(write_buffer[i]);
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
for (uint16_t i=0; i<write_len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(write_buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (write_len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
// do the reading
for (size_t i=0; i<read_len; i++) {
read_buffer[i] = transfer(sendvalue);
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Read: "));
for (uint16_t i=0; i<read_len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(read_buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (read_len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
digitalWrite(_cs, HIGH);
if (_spi) {
_spi->endTransaction();
}
return true;
}