Hi, we got a MIMXRT1064-EVK board to develop an application that was done on a iMx8QM, an added feature this time is SPI, i used the b2b_master example to try to communicate with other boards (raspberry(raspi-os), arduino uno (arduino), esp8266(arduino)) but had no luck making the MIMXRT1064 work as master or slave in SPI.
By using an oscilloscope i noticed that the MIMXRT1064 doesn't output any clock in the SCK pin during transmission, there is no activity at all on any of the SPI pin of the arduino header. I tried with the given example and also by modifying it trying to make it work, any clue what could be the reason for the SPI not working?
Solution: it was just a resistor issue, MIMXRT1064-evk doesn't come stock with the arduino header jumper resistors so i had to solder some 0402 0 ohm resistors in place, after this was done everything come back to a working status.
this is the sligthly modified code of freertos_lpspi_b2b_master just to continously (time interval) send a message on SPI.
/*
* Copyright (c) 2013 - 2015, Freescale Semiconductor, Inc.
* Copyright 2016-2019 NXP
* All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
/* FreeRTOS kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include "timers.h"
/* Freescale includes. */
#include "fsl_device_registers.h"
#include "fsl_debug_console.h"
#include "fsl_lpspi.h"
#include "fsl_lpspi_freertos.h"
#include "board.h"
#include "app.h"
/*******************************************************************************
* Definitions
******************************************************************************/
#define TRANSFER_SIZE (16U) /*! Transfer dataSize.*/
#define TRANSFER_BAUDRATE (500000U) /*! Transfer baudrate - 500k */
/*******************************************************************************
* Prototypes
******************************************************************************/
/* LPSPI user callback */
extern uint32_t LPSPI_GetInstance(LPSPI_Type *base);
/*******************************************************************************
* Variables
******************************************************************************/
lpspi_slave_handle_t g_s_handle;
uint8_t masterReceiveBuffer[TRANSFER_SIZE] = {0};
uint8_t masterSendBuffer[TRANSFER_SIZE] = {0};
uint8_t slaveSendBuffer[TRANSFER_SIZE] = {0};
SemaphoreHandle_t lpspi_sem;
/*******************************************************************************
* Definitions
******************************************************************************/
/* Task priorities. */
#define master_task_PRIORITY (configMAX_PRIORITIES - 1)
/*******************************************************************************
* Prototypes
******************************************************************************/
static void master_task(void *pvParameters);
/*******************************************************************************
* Code
******************************************************************************/
/*!
* @brief Application entry point.
*/
int main(void)
{
int i;
/* Init board hardware. */
BOARD_InitHardware();
PRINTF("FreeRTOS LPSPI master example starts.\r\n");
PRINTF("This example uses two boards to connect with one as master and anohter as slave.\r\n");
PRINTF("Master and slave are both use interrupt way.\r\n");
PRINTF("Please make sure you make the correct line connection. Basically, the connection is:\r\n");
PRINTF("LPSPI_master -- LPSPI_slave\r\n");
PRINTF(" CLK -- CLK\r\n");
PRINTF(" PCS -- PCS\r\n");
PRINTF(" SOUT -- SIN\r\n");
PRINTF(" SIN -- SOUT\r\n");
PRINTF("\r\n");
/* Initialize data in transfer buffers */
for (i = 0; i < TRANSFER_SIZE; i++)
{
masterSendBuffer[i] = i % 256;
masterReceiveBuffer[i] = 0;
slaveSendBuffer[i] = ~masterSendBuffer[i];
}
if (xTaskCreate(master_task, "Master_task", configMINIMAL_STACK_SIZE + 64, NULL, master_task_PRIORITY, NULL) !=
pdPASS)
{
PRINTF("Task creation failed!.\r\n");
while (1)
;
}
vTaskStartScheduler();
for (;;)
;
}
/*!
* @brief Task responsible for master SPI communication.
*/
static void master_task(void *pvParameters)
{
lpspi_transfer_t masterXfer;
lpspi_rtos_handle_t master_rtos_handle;
lpspi_master_config_t masterConfig;
status_t status;
LPSPI_MasterGetDefaultConfig(&masterConfig);
masterConfig.baudRate = TRANSFER_BAUDRATE;
masterConfig.whichPcs = EXAMPLE_LPSPI_MASTER_PCS_FOR_INIT;
status = LPSPI_RTOS_Init(&master_rtos_handle, EXAMPLE_LPSPI_MASTER_BASEADDR, &masterConfig, LPSPI_MASTER_CLK_FREQ);
if (status != kStatus_Success)
{
PRINTF("LPSPI master: error during initialization. \r\n");
vTaskSuspend(NULL);
}
/*Start master transfer*/
masterXfer.txData = masterSendBuffer;
masterXfer.rxData = masterReceiveBuffer;
masterXfer.dataSize = TRANSFER_SIZE;
masterXfer.configFlags = EXAMPLE_LPSPI_MASTER_PCS_FOR_TRANSFER | kLPSPI_SlaveByteSwap;
for(int j=0; j<100; j++){
status = LPSPI_RTOS_Transfer(&master_rtos_handle, &masterXfer);
if (status == kStatus_Success)
{
PRINTF("LPSPI master transfer completed successfully.\r\n");
}
else
{
PRINTF("LPSPI master transfer completed with error.\r\n");
}
vTaskDelay(1000);
}
vTaskSuspend(NULL);
}note that communication from e to the other devices work, the problem is just with the MIMX board