Failed to read/write ADXL362 data using nRF52840

[beparas]

Hello All,

I have connected nRF52840 with ADXL362 over SPI, and try to read/write data on "Power Control register".

The process I follow,

1. Rest ADXL362.

2. Write data 0x02 in "Power Control register" of ADXL362.

2. Read value of  "Power Control register" of ADXL362.

But every time I read data form ADXL362 I got 0x00 value.

Logs are attached.

For testing this I have modify SPI test code located at "nRF5_SDK_15.0.0_a53641a\examples\peripheral\spi"

Code is also attached here, will you please guide me, If I did any wrong in SPI configuration?

I am little bit confuse of "tx_buffer_length" & "rx_buffer_length" value passing in nrf_drv_spi_transfer() function.

Does the values of "tx_buffer_length" & "rx_buffer_length" are correct at line no 101 & 118 in main.c file?

Thanks in advance.

Fullscreen output.txt Download

<info> app: #########################################################
<info> app: SPI example started.
<info> SPIM: Function: nrfx_spim_init, error code: NRF_SUCCESS.
<info> app: <---- ADXL325 reset ---->
<info> SPIM: Function: spim_xfer, error code: NRF_SUCCESS.
<debug> SPIM: Event: NRF_SPIM_EVENT_END.
<info> app: Transfer completed.
<info> app:  00 00 00               |...     
<info> app: soft reset
<info> app: <--- ADXL325 set power control register --->
<info> SPIM: Function: spim_xfer, error code: NRF_SUCCESS.
<info> app: ** 0 0 0
<info> app:  00 00                  |..      
<info> app: Setting Measeurement Mode - Reg 2D before = 0
<debug> SPIM: Event: NRF_SPIM_EVENT_END.
<info> app: Transfer completed.
<info> app:  00 00 00               |...     
<info> SPIM: Function: spim_xfer, error code: NRF_SUCCESS.
<debug> SPIM: Event: NRF_SPIM_EVENT_END.
<info> app: Transfer completed.
<info> app:  00 00 00               |...     
<info> app: -----------
<info> SPIM: Function: spim_xfer, error code: NRF_SUCCESS.
<info> app: ** 0 0 0
<info> app:  00 00                  |..      
<info> app: , Reg 2D after = 0
<debug> SPIM: Event: NRF_SPIM_EVENT_END.
<info> app: Transfer completed.
<info> app:  00 00 00               |...     

Fullscreen main.c Download

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 */
#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "boards.h"
#include "app_error.h"
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define SPI_INSTANCE  0 /**< SPI instance index. */
static const nrf_drv_spi_t spi = NRF_DRV_SPI_INSTANCE(SPI_INSTANCE);  /**< SPI instance. */
static volatile bool spi_xfer_done;  /**< Flag used to indicate that SPI instance completed the transfer. */

#define TEST_STRING "Nordic"
static uint8_t       m_tx_buf[] = TEST_STRING;           /**< TX buffer. */
static uint8_t       m_rx_buf[sizeof(TEST_STRING) + 1];    /**< RX buffer. */
static const uint8_t m_length = sizeof(m_tx_buf);        /**< Transfer length. */

uint8_t tx[3] = { 0x0B, 0x00, 0x00 };
uint8_t rx[3] = { 0 };


/**
 * @brief SPI user event handler.
 * @param event
 */
void spi_event_handler(nrf_drv_spi_evt_t const * p_event,
                       void *                    p_context)
{
    spi_xfer_done = true;
    NRF_LOG_INFO("Transfer completed.");
    //NRF_LOG_INFO("%d.", p_event->type);
    //NRF_LOG_INFO("%d %d %s", p_event->data.done.rx_length, p_event->data.done.tx_length, p_event->data.done.p_tx_buffer);
//    if (m_rx_buf[0] != 0)
    if (rx[0] != 0)
    {
        NRF_LOG_INFO(" Received:");
        NRF_LOG_HEXDUMP_INFO(m_rx_buf, strlen((const char *)m_rx_buf));
    }
   NRF_LOG_HEXDUMP_INFO(rx, 3);
}


#define XL362_REG_WRITE          0x0a
#define XL362_REG_READ           0x0b
#define XL362_POWER_CTL          0x2d
#define XL362_SOFT_RESET         0x1f
#define XL362_SOFT_RESET_KEY     0x52

uint8_t adxl362_read_one_reg(uint8_t reg_address)
{
  uint8_t tx_buff[3] = {0};
  uint8_t rx_buff[3] = {0};

  // </CS down> <command byte (0x0A or 0x0B)> <address byte> <data byte> <additional data bytes for multi-byte> � </CS up>
  tx_buff[0] = XL362_REG_READ;
  tx_buff[1] = reg_address;
  tx_buff[2] = 0x00;            // dummy byte

   APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, tx_buff, 3, rx_buff, 1));
   NRF_LOG_INFO("** %d %d %d", rx[0], rx[1], rx[2]);
   NRF_LOG_HEXDUMP_INFO(rx, 2);

   return rx_buff[2];
}

void adxl362_write_one_reg(uint8_t reg_address, uint8_t reg_value)
{
  uint8_t tx_buff[3] = {0};
  uint8_t rx_buff[3] = {0};

  // </CS down> <command byte (0x0A or 0x0B)> <address byte> <data byte> <additional data bytes for multi-byte> � </CS up>
  tx_buff[0] = XL362_REG_WRITE;
  tx_buff[1] = reg_address;
  tx_buff[2] = reg_value;

   APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, tx_buff, 3, rx_buff, 3));
//   NRF_LOG_INFO("** %d %d %d", rx[0], rx[1], rx[2]);
//   NRF_LOG_HEXDUMP_INFO(rx, 2);
}

void adxl362_reset()
{
  // soft reset
  adxl362_write_one_reg(XL362_SOFT_RESET, XL362_SOFT_RESET_KEY);

  // Note: A latency of approximately 0.5 ms is required after soft reset.
  nrf_delay_ms(200);
  NRF_LOG_INFO("soft reset");
}

void beginMeasure()
{
  uint8_t reg_val = 0x0;
  // read Reg 2D before modifying for measure mode
  reg_val = adxl362_read_one_reg(XL362_POWER_CTL);
  
  NRF_LOG_INFO("Setting Measeurement Mode - Reg 2D before = %d", reg_val);

  // turn on measurement mode
  uint8_t temp_write = (reg_val | 0x02);  // turn on measurement bit in Reg 2D

  adxl362_write_one_reg(XL362_POWER_CTL, temp_write);

  nrf_delay_ms(10);
  //nrf_delay_ms(200);

  NRF_LOG_INFO("-----------");
  // read Reg 2D before modifying for measure mode
  reg_val = adxl362_read_one_reg(XL362_POWER_CTL);
  NRF_LOG_INFO(", Reg 2D after = %d", reg_val);
}

int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);

    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    NRF_LOG_INFO("#########################################################");
    NRF_LOG_INFO("SPI example started.");

    nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
#if 1
    spi_config.ss_pin   = NRF_GPIO_PIN_MAP(0,17);       //17
    spi_config.miso_pin = NRF_GPIO_PIN_MAP(0,23);       //23
    spi_config.mosi_pin = NRF_GPIO_PIN_MAP(0,21);       //21
    spi_config.sck_pin  = NRF_GPIO_PIN_MAP(0,19);       //19
#else
    spi_config.ss_pin   = SPI_SS_PIN;
    spi_config.miso_pin = SPI_MOSI_PIN;
    spi_config.mosi_pin = SPI_MISO_PIN;
    spi_config.sck_pin  = SPI_SCK_PIN;
#endif

    spi_config.frequency = NRF_SPIM_FREQ_1M;
//    spi_config.bit_order    = NRF_DRV_SPI_BIT_ORDER_LSB_FIRST;
//    spi_config.irq_priority = NRFX_SPIM_DEFAULT_CONFIG_IRQ_PRIORITY;
//    spi_config.mode = NRF_SPIM_MODE_3;
     
     ret_code_t ret = nrf_drv_spi_init(&spi, &spi_config, spi_event_handler, NULL);
     if(ret != NRF_SUCCESS)
        NRF_LOG_INFO("SPI init failed:  %d", ret);
    //APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, NULL, NULL));

    NRF_LOG_INFO("<---- ADXL325 reset ---->");
    adxl362_reset();

    NRF_LOG_INFO("<--- ADXL325 set power control register --->");
    beginMeasure();

    while (1)
    {
#if 0
        // Reset rx buffer and transfer done flag
        memset(m_rx_buf, 0, m_length);
        spi_xfer_done = false;

//        APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, tx, 3, rx, 3));
          nrf_drv_spi_transfer(&spi, tx, 3, rx, 1);
   
        NRF_LOG_INFO("SPI tx: %d", ret);

        NRF_LOG_INFO("** %d %d %d", rx[0], rx[1], rx[2]);
//        NRF_LOG_HEXDUMP_INFO(rx, 2);
 
        // read Reg 2D before modifying for measure mode
      uint8_t  reg_val = adxl362_read_one_reg(XL362_POWER_CTL);
      NRF_LOG_INFO(", Reg 2D after = %d", reg_val);
#endif
        while (!spi_xfer_done)
        {
            __WFE();
        }

        NRF_LOG_FLUSH();

//        bsp_board_led_invert(BSP_BOARD_LED_0);
        nrf_delay_ms(200);
    }
}

sdk_config.h

[Håkon Alseth]

Hi,

 

Code is also attached here, will you please guide me, If I did any wrong in SPI configuration?

You configuration looks to be correct, MSB first, SPI Mode 0.

Are you sure that you have connected the pins correctly to the SPIS device? MISO to MISO, MOSI->MOSI, etc.?

Try reading a register, for instance PARTID (0x02), as this is non-zero in reset-value.

 

I am little bit confuse of "tx_buffer_length" & "rx_buffer_length" value passing in nrf_drv_spi_transfer() function.

Does the values of "tx_buffer_length" & "rx_buffer_length" are correct at line no 101 & 118 in main.c file?

This is related to the amount of bytes to send (tx) and the expected number of bytes you read (Rx) from the sensor. This may differ from register-to-register on your SPI slave device.

This function looks a bit suspicious:

uint8_t adxl362_read_one_reg(uint8_t reg_address)
{
uint8_t tx_buff[3] = {0};
uint8_t rx_buff[3] = {0};

// </CS down> <command byte (0x0A or 0x0B)> <address byte> <data byte> <additional data bytes for multi-byte> … </CS up>
tx_buff[0] = XL362_REG_READ;
tx_buff[1] = reg_address;
tx_buff[2] = 0x00; // dummy byte

APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, tx_buff, 3, rx_buff, 1));
NRF_LOG_INFO("** %d %d %d", rx[0], rx[1], rx[2]);
NRF_LOG_HEXDUMP_INFO(rx, 2);

return rx_buff[2];
}

 

Here you are sending 3 bytes, then receiving one (rx_buff[0]), then returning index 2 in rx_buff. Given your print log, it is still 0x0, but this function is likely not working as you intend it to.

Best regards,

Håkon

[beparas]

Hello Sir,

Thanks for you replay.

I recheck the pin connection (MOSI <--> MOSI, MISO <--> MISO), are ok.

I simplify above program & try to read Analog device ID (register address 0x00), MEMS ID (0x01), Part ID (0x02) but I am getting wrong values.

As per ADXL362 datasheet default values for register address 0x00 is 0xAD,  for register 0x01 is 0x1D, for register 0x02 is 0xF2.

But I am getting wrong values for these register.

The values I am getting for register address 0x00 is 0x90,  for register 0x01 is 0x18, for register 0x02 is 0xF0.

Could you please explain the reason for wrong values?

Thanks in advance.

void spi_event_handler(nrf_drv_spi_evt_t const * p_event,
                       void *                    p_context)
{
    spi_xfer_done = true;
    NRF_LOG_INFO("Transfer completed.");
    if (m_rx_buf[0] != 0)
    {
        NRF_LOG_INFO(" Received:");
        NRF_LOG_HEXDUMP_INFO(m_rx_buf, strlen((const char *)m_rx_buf));
    }
    else
      NRF_LOG_HEXDUMP_INFO(m_rx_buf, 3);
}
		
int main(void)
{
    bsp_board_init(BSP_INIT_LEDS);

    APP_ERROR_CHECK(NRF_LOG_INIT(NULL));
    NRF_LOG_DEFAULT_BACKENDS_INIT();

    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, spi_event_handler, NULL));

    NRF_LOG_INFO("#########################################################");
    NRF_LOG_INFO("SPI example started.");

    while (1)
    {
        // Reset rx buffer and transfer done flag
        memset(m_rx_buf, 0, m_length);
        spi_xfer_done = false;

        // </CS down> <command byte (0x0A or 0x0B)> <address byte> <data byte> <additional data bytes for multi-byte> … </CS up>
        m_tx_buf[0] = 0x0B;       // Read Register
        m_tx_buf[1] = 0x00;
        m_tx_buf[2] = 0x00;       // dummy data

        APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, m_tx_buf, 3, m_rx_buf, 3));

        while (!spi_xfer_done)
        {
            __WFE();
        }

        NRF_LOG_FLUSH();

        bsp_board_led_invert(BSP_BOARD_LED_0);
        nrf_delay_ms(200);
    }
}

[Håkon Alseth]

Hi,

 

Have you scoped the signal to see how it looks? You might be running on too high SPI frequency.

You can change the frequency in spi_config.frequency = NRF_DRV_SPI_FREQ_1M.

Best regards,

Håkon

[beparas]

Hello Sir,
 
 As per your guide line I set SPI frequency to 1MHz and try to read register 0x01 (having device MEMS ID).
 I am getting wrong value 0x18 instead on 0x1D (default value).
 
 Here attached waveform of CLK & MOSI pin.

Waveform for CLK & MISO pin

 Data we are sending on MOSI is 0x0B (Read register command) , 0x01 (register address), 0x00 (dummy data).
 
 
 Next I connect my ADXL362 evaluation board to Arduino and follow this document.

 
 Logs from Arduino device showing correct data for register value 0x00, 0x01, 0x02
 
 So my ADXL362 evaluation board is not damages.
 
 But when I connect ADXL362 to nRF52840 DK I am getting wrong data.

Thanks in advance

[awneil]

So use your scope to compare what happens in the Arduino (working) case against what happens with your nRF...

Note that the Keysight scopes can capture screen images to a USB stick - much better than taking photos!

[beparas]

 Hello Sir,
 
 I connect ADXL362 to Arduino & check waveform on oscilloscope.
 I am reading register 0x01 (having device MEMS ID)
 So data I am sending on MOSI is 0x0B (Read register command) , 0x01 (register address), 0x00 (dummy data).
 
 Here is the waveform for CLK & MOSI

waveform for CLK & MISO

Arduino adds 1us delay in CLK after sending 1 byte. but nRF52840 sending continouns CLK signal (please refer previous post)

What is the reason to add delay on CLK?
If I want to add delay in CLK, Where do I add this in SPI driver?

Note: SDK version is 15.0.0_a53641a

Thanks in advance.

[beparas]

Hello Sir,

Any update on this.

Waiting for replay.

[Håkon Alseth]

Hi,

 

Judging by the scoping of CLK+MISO, the resonse is incorrect. This may indicate that there's a difference between the inputted data on MOSI.

Is there any difference in the MOSI data compared to the arduino?

Kind regards,

Håkon

[beparas]

Hello Sir,

As per ADXL362, here is command structure for read register

" </CS down> <command byte (0x0A or 0x0B)> <address byte> <data byte> <additional data bytes for multi-byte> … </CS up>"

So I am sending same command for Arduino & nRF52840. The command is
0x0B 0x01 0x00

You can check this in above attached waveform.

Thanks in advance.

[Håkon Alseth]

1. Could you post your latest source code that performs the SPI read/write?

2. Could you try only reading the 0x01 register. Do not run the Soft-reset or powerctl routine.

3. Could you post the arduino code used?

Kind regards,

Håkon

[beparas]

Hello Sir,

Thanks for replay.

1. Could you post your latest source code that performs the SPI read/write?

Ans: Please find spim_adxl362.zip file contains source code for reading 0x01 register.

3. Could you post the arduino code used?

For Arduino I follow this document

1. Open ADXL362_SimpleRead example sketch.

2. To read 0x01 register modify ADXL362 library. added readDevIDData() function in it. ADXL362.cpp file is attached here.

3. called readDevIDData() in loop.

Note: SDK version: nRF5_SDK_15.0.0_a53641a

Thanks in advance.

4237.ADXL362.cpp6747.ADXL362.h3247.spim_adxl362.zip