doc added, mega port definition

This commit is contained in:
Robin Müller 2020-10-13 00:37:09 +02:00
parent 78792e5d4a
commit 55caac63da

View File

@ -11,9 +11,24 @@
//from the core and we need to include it explicitly //from the core and we need to include it explicitly
#include <SPI.h> #include <SPI.h>
//Define which port to use for the SPI Chip Select // Define which port to use for the SPI Chip Select by using the register
// definitions. The data direction register is assigned as well.
// The ports can be looked up on the official Arduino pinout schematics.
#ifdef ARDUINO_AVR_MEGA2560
// Defines for the Arduino Mega
#define CS_PORT PORTK
#define CS_DDR DDRK
#elif defined(ARDUINO_AVR_UNO)
#define CS_PORT PORTD
#define CS_DDR DDRD
#elif defined(__SAM3X8E__)
// Define for the Arduino Due
#define CS_PORT PORTC #define CS_PORT PORTC
#define CS_DDR DDRC #define CS_DDR DDRC
#else
#define CS_PORT PORTC
#define CS_DDR DDRC
#endif
static const uint8_t COMMAND_TRANSFER_SPI = 1; static const uint8_t COMMAND_TRANSFER_SPI = 1;
@ -45,9 +60,13 @@ void sendData(uint8_t *data, size_t len) {
void transferSPI(uint8_t address, uint8_t *data, size_t datalen) { void transferSPI(uint8_t address, uint8_t *data, size_t datalen) {
SPI.beginTransaction(SPISettings(14000000, MSBFIRST, SPI_MODE3)); SPI.beginTransaction(SPISettings(14000000, MSBFIRST, SPI_MODE3));
// The specified address is the bit where the last bit is port 0
// and the first bit is port 7. It is inverted because the SPI protocol
// requires the slave select to be driven low.
CS_PORT = ~address; CS_PORT = ~address;
SPI.transfer(data, datalen); SPI.transfer(data, datalen);
delay(100); delay(100);
// Pull the slave select high again.
CS_PORT = 0xff; CS_PORT = 0xff;
SPI.endTransaction(); SPI.endTransaction();
@ -157,7 +176,10 @@ void serialEvent() {
} }
void setup() { void setup() {
// Set data direction of selected port to output.
CS_DDR = 0xff; CS_DDR = 0xff;
// Drive all the slave selects high as required for the SPI protocol
// if no transfer is going on.
CS_PORT = 0xff; CS_PORT = 0xff;
Serial.begin(BAUD_RATE); Serial.begin(BAUD_RATE);
Serial.println("Setting up Arduino IO interface board."); Serial.println("Setting up Arduino IO interface board.");