no communication between custom PCB and mpu6050

[Adrian]

Hello,

I used a breakout board of the MPU6050 (playground.arduino.cc/.../mpu-6050.jpg) and the nrf52832 development board. There is communication between the two and I have no problems retrieving data from the MPU6050. However, when I put the mpu6050 and nrf52832 on a custom PCB there is no communication between the two (i.e. no clock signals). The MPU6050 are close to the nrf52832 so there is minimal noise interference. I can provide more information. I'm just not sure what I should add.

Has anyone come across this problem or has ideas to solve this?

[bjorn-spockeli]

Hi Adrian,

I suggest that you take a look at the nRF5x examples in this GitHub repo .

Best regards

Bjørn

[cd.barahona]

Hi Bjorn,

I have used that repo, but I have problems building the program (example nrf_mpu_simple).

This is the code and errors:

 /* 
  * This example is not extensively tested and only 
  * meant as a simple explanation and for inspiration. 
  * NO WARRANTY of ANY KIND is provided. 
  */

#include <stdio.h>
#include "boards.h"
#include "app_uart.h"
#include "app_error.h"
#include "nrf_delay.h"
#include "app_mpu.h"

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

typedef struct
{
    uint8_t             smplrt_div;         // Divider from the gyroscope output rate used to generate the Sample Rate for the MPU-9150. Sample Rate = Gyroscope Output Rate / (1 + SMPLRT_DIV)
    sync_dlpf_config_t  sync_dlpf_gonfig;   // Digital low pass fileter and external Frame Synchronization (FSYNC) configuration structure
    gyro_config_t       gyro_config;        // Gyro configuration structure
    accel_config_t      accel_config;       // Accelerometer configuration structure
}app_mpu_config_t;

/**@brief Function for initializing the nrf log module.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


void mpu_init(void)
{
    ret_code_t ret_code;
    // Initiate MPU driver
    ret_code = app_mpu_init();
    APP_ERROR_CHECK(ret_code); // Check for errors in return value
    
    // Setup and configure the MPU with intial values
    app_mpu_config_t p_mpu_config = MPU_DEFAULT_CONFIG(); // Load default values
    p_mpu_config.smplrt_div = 19;   // Change sampelrate. Sample Rate = Gyroscope Output Rate / (1 + SMPLRT_DIV). 19 gives a sample rate of 50Hz
    p_mpu_config.accel_config.afs_sel = AFS_2G; // Set accelerometer full scale range to 2G
    ret_code = app_mpu_config(&p_mpu_config); // Configure the MPU with above values
    APP_ERROR_CHECK(ret_code); // Check for errors in return value 
}

/**
 * @brief Function for main application entry.
 */
int main(void)
{    
    uint32_t err_code;
    
    // Initialize.
    log_init();
	NRF_LOG_INFO("\033[2J\033[;H"); // Clear screen
    
    mpu_init();
    
    // Start execution.
    NRF_LOG_INFO("MPU Free Fall Interrupt example.");
    
    accel_values_t acc_values;
    uint32_t sample_number = 0;
    
    while(1)
    {
        if(NRF_LOG_PROCESS() == false)
        {
            // Read accelerometer sensor values
            err_code = app_mpu_read_accel(&acc_values);
            APP_ERROR_CHECK(err_code);
            // Clear terminal and print values
            NRF_LOG_INFO("\033[3;1HSample # %d\r\nX: %06d\r\nY: %06d\r\nZ: %06d", ++sample_number, acc_values.x, acc_values.y, acc_values.z);
            nrf_delay_ms(250);
        }
    }
}

/** @} */

Building ‘template_pca10040’ from solution ‘template_pca10040’ in configuration ‘Debug’
  Compiling ‘main.c’
    conflicting types for 'app_mpu_config_t'
    main.c
    previous declaration of 'app_mpu_config_t' was here
    passing argument 1 of 'app_mpu_config' from incompatible pointer type [-Wincompatible-pointer-types]
    main.c
    expected 'app_mpu_config_t * {aka struct <anonymous> *}' but argument is of type 'app_mpu_config_t * {aka struct <anonymous> *}'
Build failed

Can you help me with this. I do not know where is the error.

[run_ar]

Guess this is handled in your separate question? devzone.nordicsemi.com/.../nrf52832-and-mpu6050