Hello everyone, I'm developing a wearable device based on nRF52832 which reads IMU (ICM20948) data using TWI.
The problem is that if I try to use the code with a custom board it works fine, while if I use a breadboard with the breakout kits provided by sparkfun it doesn't work. I've done the same connections of the PCB, but I get the error: ERROR 13 [NRF_ERROR_TIMEOUT]. No softdevice used
Here's the simple code used for testing:
#include <stdio.h>
#include "boards.h"
#include "app_uart.h"
#include "app_error.h"
#include "nrf_delay.h"
#include "app_ICM20948.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "SEGGER_RTT.h"
#define PI 3.1415
/**@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 icm_init(void)
{
/*ICM-20948 initialization and configuration */
ret_code_t ret_code;
// Initiate ICM driver
ret_code = app_icm_init();
APP_ERROR_CHECK(ret_code); // Check for errors in return value
ICM20948_reset();
ICM20948_selectAutoClockSource();
ICM20948_enableAccelGyro();
ICM20948_configAccel();
ICM20948_configGyro();
ICM20948_setGyroSrd(21); //19 nella versione MPU. ODR is computed as follows: 1.1 kHz/(1+GYRO_SMPLRT_DIV[7:0]) 1100/(1+21) = 50 Hz
ICM20948_setAccelSrd(21);//19 nella versione MPU (in ICM sono due registri separati, mentre in MPU è unico )
//ODR is computed as follows: 1.125 kHz/(1+ACCEL_SMPLRT_DIV[11:0]) 1125/(21+1) = 51.136 Hz
ICM20948_resetMag();
app_icm_magn_config_t magnetometer_config;
magnetometer_config.mode = MAG_CNTL2_MODE_100HZ; //continuous measurment mode 4 = 100 Hz
ret_code = app_icm_magnetometer_init(&magnetometer_config);
APP_ERROR_CHECK(ret_code);
}
/**
* @brief Function for main application entry.
*/
int main(void)
{
uint32_t err_code;
float deltat=0.025;
float mx;
float my;
float mz;
float quat[4];
accel_values_t acc_values;
magn_values_t magn_values;
gyro_values_t gyro_values;
accel_values_float_t acc;
gyro_values_float_t gyro;
// Initialize.
log_init();
NRF_LOG_INFO("\033[2J\033[;H"); // Clear screen
icm_init();
// Start execution.
NRF_LOG_INFO("MPU Free Fall Interrupt example.");
while(1)
{
for (int i=0;i<4; i++)
{
//ICM-20948
//Accelerometer data read
err_code = app_icm_read_accel(&acc_values);
APP_ERROR_CHECK(err_code);
//sensitivity 2g
// acc.x=((acc_values.x)/16384.)+0.00274279364;
// acc.y=((acc_values.y)/16384.)+0.0255990699;
// acc.z=((acc_values.z)/16384.)-0.02146649;
//sensitivity 4g
acc.x=((acc_values.x)/4096.)-0.0217083115;
acc.y=((acc_values.y)/4096.)+0.0340574495;
acc.z=((acc_values.z)/4096.)-0.02073884;
//Gyroscope data read
err_code = app_icm_read_gyro(&gyro_values);
APP_ERROR_CHECK(err_code);
//sensitivity 500 dps
gyro.x=(gyro_values.x/65.54)*PI/180.0f-0.00743509503;
gyro.y=(gyro_values.y/65.54)*PI/180.0f+0.0040876139;
gyro.z=(gyro_values.z/65.54)*PI/180.0f-0.0127511621;
//Magnetometer data read
err_code = app_icm_read_magnetometer(&magn_values, NULL);
APP_ERROR_CHECK(err_code);
mx=(((magn_values.x)*0.15)+16.0499992)*1.08809519;
my=(((magn_values.y)*0.15)+47.0999985)*1.00882995;
mz=(((magn_values.z)*0.15)-72)*0.917670667;
nrf_delay_ms(25);
}
}
}
/** @} */
I even tried with the twi scanner example, and it finds the IMU at the adress 0x68, so it seems that the connection is fine...
I'm using the library "nrf5-mpu-examples"
The error seems to rise after the function app_icm_magnetometer_init(&magnetometer_config) is called. That function is in void icm_init(void).
UPDATE: Solved. It was just a problem of pull-ups in the breakout board by sparkfun, excluding them and using external pull ups solved the issue!
Thanks anyways
