使用VSPI接口前提用esp32作为主机，配合scl3300的spi传输协议即Off-frame协议，初始化scl3300相关函数

1. 引入SPI库

#include <SPI.h>

2. 定义SPI通信引脚

#define SCL3300_CS 5
#define SCL3300_MOSI 23
#define SCL3300_MISO 19
#define SCL3300_SCK 18

3. 定义SPI对象

SPIClass scl3300_spi(VSPI);

4. 初始化SPI

scl3300_spi.begin(SCL3300_SCK, SCL3300_MISO, SCL3300_MOSI, SCL3300_CS);
scl3300_spi.setBitOrder(MSBFIRST);
scl3300_spi.setDataMode(SPI_MODE3);
scl3300_spi.setFrequency(1000000); // 设置SPI时钟频率为1MHz

5. 定义读写函数

byte scl3300_write(byte addr, byte data)
{
  byte response = 0;
  byte packet[2] = {addr, data};
  digitalWrite(SCL3300_CS, LOW);
  scl3300_spi.transfer(packet, response, sizeof(packet));
  digitalWrite(SCL3300_CS, HIGH);
  return response;
}

byte scl3300_read(byte addr)
{
  byte response = 0;
  byte packet[2] = {addr | 0x80, 0x00};
  digitalWrite(SCL3300_CS, LOW);
  scl3300_spi.transfer(packet, response, sizeof(packet));
  digitalWrite(SCL3300_CS, HIGH);
  return response;
}

6. 调用读写函数进行数据传输

byte response = scl3300_write(0x00, 0x01); // 写入数据
byte data = scl3300_read(0x01); // 读取数据