Hi!
I'm trying to get the MPU-9250 chip working through SPI with my nRF52832. But I don't seem to have much luck.
I have created a basic program for testing, based on the peripheral/spi example from the SDK. It's supposed to make the LED I have on GPIO 3 blink, but the LED stays constant on.
Could i get a helping hand with this?
/* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.
*
* The information contained herein is property of Nordic Semiconductor ASA.
* Terms and conditions of usage are described in detail in NORDIC
* SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
*
* Licensees are granted free, non-transferable use of the information. NO
* WARRANTY of ANY KIND is provided. This heading must NOT be removed from
* the file.
*
*/
#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "boards.h"
#include "app_error.h"
#include <string.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. */
static uint8_t m_tx_buf[] = { 245 }; // The WHO_AM_I register + read bit
static uint8_t m_rx_buf[2]; /* RX buffer. */
static const uint8_t m_length = 2; /* Transfer length. */
/**
* @brief SPI user event handler.
* @param event
*/
void spi_event_handler(nrf_drv_spi_evt_t const * p_event)
{
spi_xfer_done = true;
NRF_LOG_PRINTF(" Transfer completed.\r\n");
nrf_gpio_pin_clear(3);
NRF_LOG_PRINTF(" Received: %s\r\n",m_rx_buf);
}
int main(void)
{
nrf_gpio_cfg_output(3); // CH1, LED used for debug
nrf_drv_spi_config_t spi_config = {
.sck_pin = 10,
.mosi_pin = 9,
.miso_pin = 8,
.ss_pin = 7,
.irq_priority = CONCAT_3(SPI, 0, _CONFIG_IRQ_PRIORITY),
.orc = 0xFF,
.frequency = NRF_DRV_SPI_FREQ_125K,
.mode = NRF_DRV_SPI_MODE_3,
.bit_order = NRF_DRV_SPI_BIT_ORDER_MSB_FIRST
};
APP_ERROR_CHECK(nrf_drv_spi_init(&spi, &spi_config, spi_event_handler));
nrf_gpio_pin_clear(3);
nrf_delay_ms(200);
while(1)
{
spi_xfer_done = false;
nrf_gpio_pin_set(3);
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, m_tx_buf, 1, m_rx_buf, m_length));
while (!spi_xfer_done)
{
__WFE();
}
nrf_delay_ms(200);
}
}
Edit:
So I've tried running Øyvind's code, and I find the behavior quite peculiar. I have made some changes to his code, to better understand the state of the program. The state of the program is indicated by LEDs on the GPIOs 3, 2, 31, 30, 29, 28. Note that I'm not using the standard nRF52 DK, but a custom board.
void spi_event_handler(nrf_drv_spi_evt_t const * p_event)
{
nrf_gpio_pin_set(3);
nrf_delay_ms(200);
}
int main(void)
{
nrf_gpio_cfg_output(3); // CH1, LED used for debug
nrf_gpio_cfg_output(2); // CH2, LED used for debug
nrf_gpio_cfg_output(31); // CH3, LED used for debug
nrf_gpio_cfg_output(30); // CH4, LED used for debug
nrf_gpio_cfg_output(29); // CH5, LED used for debug
nrf_gpio_cfg_output(28); // CH6, LED used for debug
nrf_drv_spi_config_t spi_config = {
.sck_pin = 10,
.mosi_pin = 9,
.miso_pin = 8,
.ss_pin = 7,
.irq_priority = 3,
.orc = 0xFF,
.frequency = NRF_DRV_SPI_FREQ_125K,
.mode = NRF_DRV_SPI_MODE_3,
.bit_order = NRF_DRV_SPI_BIT_ORDER_MSB_FIRST,
};
uint32_t err_code = nrf_drv_spi_init(&spi, &spi_config, spi_event_handler);
if (err_code != NRF_SUCCESS)
{
nrf_gpio_pin_set(2);
}
while(1)
{
nrf_gpio_pin_set(31);
nrf_delay_ms(200);
while(nrf_drv_spi_transfer(&spi, m_tx_buf, 1, m_rx_buf, m_length) != NRF_SUCCESS)
{
nrf_gpio_pin_set(30);
nrf_delay_ms(200); //Wait for the previous transfer to finish
}
nrf_gpio_pin_set(29);
__WFE();
nrf_gpio_pin_set(28);
}
}
The state of the LEDs when I run the code: 31 and 29 are constant active, while 3, 2, 30 and 28 are constant off.
