# SPI Implementation with source code in C++

To work with the SPI, you also need to add a specific Kernel module: [Spidev](https://elixir.bootlin.com/linux/latest/source/drivers/spi/spidev.c). The Raspberry Pi supports this module, you need to configure it by invoking `raspi-config`, and then select `3 Interfacing Options` and `P4 SPI`.

To access SPI functions with C/C++, you can use the [spidev wrapper library](https://github.com/milekium/spidev-lib). Following the [example code](https://raw.githubusercontent.com/milekium/spidev-lib/master/sample/spidev-testcpp.cc), you need to configure the SPI connection, then open the device that you want to connect to, and then use the library method for reading and writing data.

```
//SOURCE: https://raw.githubusercontent.com/milekium/spidev-lib/master/sample/spidev-testcpp.cc
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <spidev_lib++.h>

spi_config_t spi_config;
uint8_t tx_buffer[32];
uint8_t rx_buffer[32];

int  main( void)
{

  SPI *mySPI = NULL;

  spi_config.mode=0;
  spi_config.speed=1000000;
  spi_config.delay=0;
  spi_config.bits_per_word=8;

  mySPI=new SPI("/dev/spidev1.0",&spi_config);

  if (mySPI->begin())
  {
    memset(tx_buffer,0,32);
    memset(rx_buffer,0,32);
    sprintf((char*)tx_buffer,"hello world");
    printf("sending %s, to spidev2.0 in full duplex \n ",(char*)tx_buffer);
    mySPI->xfer(tx_buffer,strlen((char*)tx_buffer),rx_buffer,strlen((char*)tx_buffer));
    printf("rx_buffer=%s\n",(char *)rx_buffer);
    //mySPI->end();
    delete mySPI;
  }
 return 1;
}
```


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