SPI/I2C Step on nRF52833 to read BMI160 outputs

[Katie Newell]

Hello,

I am trying to read BMI160 outputs using SPI protocol but I am struggling to get a successful build from my code. 

The build fails at the first line of my code //static nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE( 0 ); // SPI instance// 

The complier doesn't recognise NRF_DRV_SPI_INSTANCE even though it is in the libraries into nrf_drv_spi library. 

I don't know what I am doing wrong? Could I get some help please?

Please find below my code. 

Thanks a lot.

[awneil]

Katie Newell said:

The complier doesn't recognise NRF_DRV_SPI_INSTANCE even though it is in the libraries into nrf_drv_spi library

Have you made the necessary settings in sdk_config.h ?

[Katie Newell]

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nrf.h"
#include "nrf_drv_saadc.h"
#include "nrf_drv_ppi.h"
#include "nrf_drv_timer.h"
#include "nrf_drv_twi.h"
#include "nrf_drv_spi.h"
#include "nrf_drv_spis.h"
#include "boards.h"
#include "app_error.h"
#include "sdk_config.h"
#include "nrf_delay.h"
#include "app_util_platform.h"
#include "nrf_pwr_mgmt.h"
#include <string.h>
#include "nrf_gpio.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#include "bmi160.h"


#define SPI_SS_PIN 28 
#define SPI_MISO_PIN 12 
#define SPI_MOSI_PIN 25
#define SPI_SCK_PIN 29

static nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE( 0 );  // SPI instance
struct bmi160_dev sensor ; // bmi160 sensor struct 


void user_delay_ms(uint32_t period) { 
	// delay time
	
	
  nrf_delay_ms( period ) ;
} // user_delay_ms()

static uint8_t       no_use = 0xFF ;

int8_t spi1_read_transfer(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t length)
{
	ret_code_t ret ;
	uint8_t read_temp[ length + 1 ] ;
	
    ret = nrf_drv_spi_transfer(&spi, &reg_addr, 1, read_temp, length + 1 ) ;	
	nrf_delay_ms(5); 
	
	for( int i = 1 ; i < length + 1 ; i ++ )
	  reg_data[i-1] = read_temp[i] ;
	
	return (int8_t)ret;	
}

int8_t spi1_write_transfer(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t length)
{
	ret_code_t ret;
	uint8_t write_temp[ length + 1 ] ;
	write_temp[0] = reg_addr ;
	for( int i = 1 ; i < length + 1 ; i ++ )
	  write_temp[i] = reg_data[i-1] ;

    ret = nrf_drv_spi_transfer(&spi, write_temp, length + 1, &no_use, 1 ) ;
	nrf_delay_ms(5) ;
	
	return (int8_t)ret;	
}

int main(void){   
	
    bsp_board_init(BSP_INIT_LEDS);
    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

  	// init spi // 
  	nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG; 
        spi_config.ss_pin   = SPI_SS_PIN; 
        spi_config.miso_pin = SPI_MISO_PIN;
        spi_config.mosi_pin = SPI_MOSI_PIN;
        spi_config.sck_pin  = SPI_SCK_PIN;

    APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, NULL, NULL));
		
  	// init bmi160 sensor // 
	sensor.id = 0 ; 
        sensor.interface = BMI160_SPI_INTF;
        sensor.read = spi1_read_transfer;
        sensor.write = spi1_write_transfer;
        sensor.delay_ms = user_delay_ms;

	int8_t rslt = BMI160_OK;
        uint8_t reg_addr = BMI160_CHIP_ID_ADDR; // chip_id address // chip_id
        uint8_t data;
        uint16_t len = 1;
    rslt = bmi160_get_regs(reg_addr, &data, len, &sensor); // read sensor chip_id // 

    // print result // 
		SEGGER_RTT_printf( 0, "rslt = %d \n", rslt ) ; 
		SEGGER_RTT_printf( 0, "data = %d \n", data ) ; 
		
} 

[Katie Newell]

Thank you Awneil.

Sorry for the code post. I repost it below.

Could you tell me please what settings I need to made into sdk_config.h ?

Thank you very much.

[awneil]

not used an nRF52833, so don't know.

suggest you start with an SDK example which has working SPI ...

[Edvin]

So you want to use the SPI 0 instance. Please make sure these are set in sdk_config.h:

#define SPI_ENABLED 1
#define SPI0_ENABLED 1
#define SPI0_USE_EASY_DMA 1

These are the same settings that are set in the spi example from SDK\examples\peripheral\spi

Best regards,

Edvin