I am using CubeMx and CubeIde with two nucleo-F042K6 boards. I am fairly new to development on STM32 boards.
I am attempting to implement SPI communciation between the two boards. I use a logic analyzer to monitor the communication signals.
I have set the one board up as a full duplex master, the other as a full duplex slave. The code on both machines is identical with the exception the the Master resets and sets the enable line. I would tie enable low except the logic analyzer needs the toggle to decode the SPI signals.
As you will see I use #defines to select the operations I want to perform
When I set the Master to TX__ONLY and the Slave to RX_ONLY the results are acceptable but not exact; the first four characters received by the slave are zero ('\0') otherwise the message is complete. I could live with that as long at it is repeatable but I don't think that is the way it would operate.
When I set the Master RX_ONLY and the Slave to TX_ONLY, the results are unacceptable. Master clocks out zeros ('\0') as is normal. Unfortunately the Slave Message is a bunch of random characters. I verified the the data I see on the MOSI line of the logic analyzer is received by the Master.
When I set ht MASTER to TX_RX_ and the Slave to TX_RX I can see the the Master message is complete on the logic Analyzer. Again there is only random data on the MISO data line. The Slave message is more random characters.
I have looked at a number of sample codes and documentation. They all suggest that this should be a simple, straight forward implementation so I must be missing something terribly simple.
I eventually want to implement SPI with DMA but if I have to get the simple implementation working first.
I would appreciate any suggestions and pointers.
Master code follows:
Master code follows:
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2023 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
SPI_HandleTypeDef hspi1;
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
#define SPI_BUFSZ 50
char Spi_Tx_Buffer[SPI_BUFSZ];
char Spi_Rx_Buffer[SPI_BUFSZ];
int kntr1;
int kntr2;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_SPI1_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_USART2_UART_Init();
MX_SPI1_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
//#define __TX_RX__
#define __TX_RX__
while (1)
{
#ifdef __TX_RX__
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
memset(Spi_Tx_Buffer, 0, SPI_BUFSZ);
memset(Spi_Rx_Buffer, 0, SPI_BUFSZ);
sprintf(Spi_Tx_Buffer, "<M->S TxRx:%d>\r\n", kntr2++);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, RESET);
HAL_SPI_TransmitReceive(&hspi1, Spi_Tx_Buffer,
Spi_Rx_Buffer, 20, HAL_MAX_DELAY);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, SET);
#endif
#ifdef __TX_ONLY__
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
memset(Spi_Tx_Buffer, 0, SPI_BUFSZ);
memset(Spi_Rx_Buffer, 0, SPI_BUFSZ);
sprintf(Spi_Tx_Buffer, "<M->S Tx:%d>\r\n", kntr2++);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, RESET);
HAL_SPI_Transmit(&hspi1, Spi_Tx_Buffer, 20, HAL_MAX_DELAY);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, SET);
#endif
#ifdef __RX_ONLY__
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
memset(Spi_Tx_Buffer, 0, SPI_BUFSZ);
memset(Spi_Rx_Buffer, 0, SPI_BUFSZ);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, RESET);
HAL_SPI_Receive(&hspi1, Spi_Rx_Buffer, 20, HAL_MAX_DELAY);
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, SET);
#endif
HAL_Delay(800);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48;
RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI48;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief SPI1 Initialization Function
* @param None
* @retval None
*/
static void MX_SPI1_Init(void)
{
/* USER CODE BEGIN SPI1_Init 0 */
/* USER CODE END SPI1_Init 0 */
/* USER CODE BEGIN SPI1_Init 1 */
/* USER CODE END SPI1_Init 1 */
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_HIGH;
hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_64;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 7;
hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI1_Init 2 */
/* USER CODE END SPI1_Init 2 */
}
/**
* @brief USART2 Initialization Function
* @param None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 38400;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* @param None
* @retval None
*/
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOF_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, SPI1_CS_Pin|t2_Pin, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(LED1_GPIO_Port, LED1_Pin, GPIO_PIN_RESET);
/*Configure GPIO pins : SPI1_CS_Pin t2_Pin */
GPIO_InitStruct.Pin = SPI1_CS_Pin|t2_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pin : LED1_Pin */
GPIO_InitStruct.Pin = LED1_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LED1_GPIO_Port, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
I changed the clock frequency.
I placed separate transmit and receive function back to back. No joy.
I have used different nucleo boards. Still the same results.
I have changed the Clock Polarity and Clock Phase. Same results.