100 lines
2.8 KiB
Arduino
100 lines
2.8 KiB
Arduino
|
|
||
|
|
|
||
|
|
/* The ESP32 has four SPi buses, however as of right now only two of
|
||
|
|
* them are available to use, HSPI and VSPI. Simply using the SPI API
|
||
|
|
* as illustrated in Arduino examples will use VSPI, leaving HSPI unused.
|
||
|
|
*
|
||
|
|
* However if we simply intialise two instance of the SPI class for both
|
||
|
|
* of these buses both can be used. However when just using these the Arduino
|
||
|
|
* way only will actually be outputting at a time.
|
||
|
|
*
|
||
|
|
* Logic analyser capture is in the same folder as this example as
|
||
|
|
* "multiple_bus_output.png"
|
||
|
|
*
|
||
|
|
* created 30/04/2018 by Alistair Symonds
|
||
|
|
*/
|
||
|
|
#include <SPI.h>
|
||
|
|
|
||
|
|
// Define ALTERNATE_PINS to use non-standard GPIO pins for SPI bus
|
||
|
|
|
||
|
|
#ifdef ALTERNATE_PINS
|
||
|
|
#define VSPI_MISO 2
|
||
|
|
#define VSPI_MOSI 4
|
||
|
|
#define VSPI_SCLK 0
|
||
|
|
#define VSPI_SS 33
|
||
|
|
|
||
|
|
#define HSPI_MISO 26
|
||
|
|
#define HSPI_MOSI 27
|
||
|
|
#define HSPI_SCLK 25
|
||
|
|
#define HSPI_SS 32
|
||
|
|
#else
|
||
|
|
#define VSPI_MISO MISO
|
||
|
|
#define VSPI_MOSI MOSI
|
||
|
|
#define VSPI_SCLK SCK
|
||
|
|
#define VSPI_SS SS
|
||
|
|
|
||
|
|
#define HSPI_MISO 12
|
||
|
|
#define HSPI_MOSI 13
|
||
|
|
#define HSPI_SCLK 14
|
||
|
|
#define HSPI_SS 15
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if CONFIG_IDF_TARGET_ESP32S2 || CONFIG_IDF_TARGET_ESP32S3
|
||
|
|
#define VSPI FSPI
|
||
|
|
#endif
|
||
|
|
|
||
|
|
static const int spiClk = 1000000; // 1 MHz
|
||
|
|
|
||
|
|
//uninitalised pointers to SPI objects
|
||
|
|
SPIClass * vspi = NULL;
|
||
|
|
SPIClass * hspi = NULL;
|
||
|
|
|
||
|
|
void setup() {
|
||
|
|
//initialise two instances of the SPIClass attached to VSPI and HSPI respectively
|
||
|
|
vspi = new SPIClass(VSPI);
|
||
|
|
hspi = new SPIClass(HSPI);
|
||
|
|
|
||
|
|
//clock miso mosi ss
|
||
|
|
|
||
|
|
#ifndef ALTERNATE_PINS
|
||
|
|
//initialise vspi with default pins
|
||
|
|
//SCLK = 18, MISO = 19, MOSI = 23, SS = 5
|
||
|
|
vspi->begin();
|
||
|
|
#else
|
||
|
|
//alternatively route through GPIO pins of your choice
|
||
|
|
vspi->begin(VSPI_SCLK, VSPI_MISO, VSPI_MOSI, VSPI_SS); //SCLK, MISO, MOSI, SS
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef ALTERNATE_PINS
|
||
|
|
//initialise hspi with default pins
|
||
|
|
//SCLK = 14, MISO = 12, MOSI = 13, SS = 15
|
||
|
|
hspi->begin();
|
||
|
|
#else
|
||
|
|
//alternatively route through GPIO pins
|
||
|
|
hspi->begin(HSPI_SCLK, HSPI_MISO, HSPI_MOSI, HSPI_SS); //SCLK, MISO, MOSI, SS
|
||
|
|
#endif
|
||
|
|
|
||
|
|
//set up slave select pins as outputs as the Arduino API
|
||
|
|
//doesn't handle automatically pulling SS low
|
||
|
|
pinMode(vspi->pinSS(), OUTPUT); //VSPI SS
|
||
|
|
pinMode(hspi->pinSS(), OUTPUT); //HSPI SS
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
// the loop function runs over and over again until power down or reset
|
||
|
|
void loop() {
|
||
|
|
//use the SPI buses
|
||
|
|
spiCommand(vspi, 0b01010101); // junk data to illustrate usage
|
||
|
|
spiCommand(hspi, 0b11001100);
|
||
|
|
delay(100);
|
||
|
|
}
|
||
|
|
|
||
|
|
void spiCommand(SPIClass *spi, byte data) {
|
||
|
|
//use it as you would the regular arduino SPI API
|
||
|
|
spi->beginTransaction(SPISettings(spiClk, MSBFIRST, SPI_MODE0));
|
||
|
|
digitalWrite(spi->pinSS(), LOW); //pull SS slow to prep other end for transfer
|
||
|
|
spi->transfer(data);
|
||
|
|
digitalWrite(spi->pinSS(), HIGH); //pull ss high to signify end of data transfer
|
||
|
|
spi->endTransaction();
|
||
|
|
}
|