Problems using USART to send NMEA commands to X-NUCLEO-GNSS1-A

Forum|Forum|5 years ago
February 4, 2021
3 replies
1482 views

Hello,

I've been trying to implement a positioning sensor using the X-NUCLEO-GNSS1-A1 expansion board using a NUCLEO F401RE, but I am facing problems sending NMEA commands through USART.

I am trying to deactivate the NMEA messages using the $PSTMNMEAONOFF,0 and request a single NMEA message using the $PSTMNMEAREQUEST, but the module keeps sending the automatic messages and not responding to the $PSTMNMEAREQUEST command.

Do I need to enable some setting for the X-NUCLEO-GNSS1-A1 respond to the commands I am sending via USART?

Am I sending it correctly?

Thanks in advance,

Best regards,

João

/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file : main.c
 * @brief : Main program body
 ******************************************************************************
 * @attention
 *
 * <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.
 * All rights reserved.</center></h2>
 *
 * This software component is licensed by ST under BSD 3-Clause license,
 * the "License"; You may not use this file except in compliance with the
 * License. You may obtain a copy of the License at:
 * opensource.org/licenses/BSD-3-Clause
 *
 ******************************************************************************
 */
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
 
/* USER CODE BEGIN PV */
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */
void Console_Write(uint8_t *string){
HAL_UART_Transmit(&huart2, string, strlen((char *)string), 1000);
}
 
static volatile _read = 0;
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
_read = 1;
}
 
static const char *NMEA_ON_OFF = "$PSTMNMEAONOFF,0\n\r";
static const char *gpgll_msg = "$PSTMGETRTCTIME\n\r";
/* 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 */
	char read_buf[180] = {0};
	//int i;
	//int j = 0;
	HAL_StatusTypeDef ret = 0xFF;
 /* 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_USART1_UART_Init();
 MX_USART2_UART_Init();
 
 /* USER CODE BEGIN 2 */
 
 HAL_GPIO_WritePin(WAKE_UP_GPIO_Port, WAKE_UP_Pin, 0x00);
 HAL_GPIO_WritePin(nRESET_GPIO_Port, nRESET_Pin, 0xFF);
 
 Console_Write("DISABLING AUTIMATIC MESSAGES\n\r");
 HAL_UART_Transmit(&huart1, *NMEA_ON_OFF, strlen(NMEA_ON_OFF), 1000);
 
 /* USER CODE END 2 */
 
 
 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
 while (1)
 {
 /* USER CODE END WHILE */
 
 /* USER CODE BEGIN 3 */
 
	 Console_Write("Sending Request\n\r");
	 HAL_UART_Transmit(&huart1, *gpgll_msg, strlen(gpgll_msg), 1000);
 
	 Console_Write("Received:\n\r");
	 HAL_UART_Receive(&huart1, &read_buf, sizeof(read_buf), 1000);
 
	 Console_Write(read_buf);
	 HAL_Delay(1000);
 }
 /* USER CODE END 3 */
}
 
/**
 * @brief System Clock Configuration
 * @retval None
 */
void SystemClock_Config(void)
{
 RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
 
 /** Configure the main internal regulator output voltage
 */
 __HAL_RCC_PWR_CLK_ENABLE();
 __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
 /** Initializes the RCC Oscillators according to the specified parameters
 * in the RCC_OscInitTypeDef structure.
 */
 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
 RCC_OscInitStruct.HSIState = RCC_HSI_ON;
 RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
 RCC_OscInitStruct.PLL.PLLM = 16;
 RCC_OscInitStruct.PLL.PLLN = 336;
 RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
 RCC_OscInitStruct.PLL.PLLQ = 4;
 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_CLOCKTYPE_PCLK2;
 RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
 RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
 RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
 {
 Error_Handler();
 }
}
 
/**
 * @brief USART1 Initialization Function
 * @param None
 * @retval None
 */
static void MX_USART1_UART_Init(void)
{
 
 /* USER CODE BEGIN USART1_Init 0 */
 
 /* USER CODE END USART1_Init 0 */
 
 /* USER CODE BEGIN USART1_Init 1 */
 
 /* USER CODE END USART1_Init 1 */
 huart1.Instance = USART1;
 huart1.Init.BaudRate = 9600;
 huart1.Init.WordLength = UART_WORDLENGTH_8B;
 huart1.Init.StopBits = UART_STOPBITS_1;
 huart1.Init.Parity = UART_PARITY_NONE;
 huart1.Init.Mode = UART_MODE_TX_RX;
 huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
 huart1.Init.OverSampling = UART_OVERSAMPLING_16;
 if (HAL_UART_Init(&huart1) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN USART1_Init 2 */
 
 /* USER CODE END USART1_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 = 115200;
 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;
 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};
 
 /* GPIO Ports Clock Enable */
 __HAL_RCC_GPIOC_CLK_ENABLE();
 __HAL_RCC_GPIOH_CLK_ENABLE();
 __HAL_RCC_GPIOA_CLK_ENABLE();
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOA, WAKE_UP_Pin|nRESET_Pin, GPIO_PIN_RESET);
 
 /*Configure GPIO pin : PC13 */
 GPIO_InitStruct.Pin = GPIO_PIN_13;
 GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
 
 /*Configure GPIO pins : WAKE_UP_Pin nRESET_Pin */
 GPIO_InitStruct.Pin = WAKE_UP_Pin|nRESET_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);
 
 /* EXTI interrupt init*/
 HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
 
}
 
/* 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 */
 
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

This topic has been closed for replies.

darla14

Associate III

This is a a good question ! Any answer on that> Please post.

F

Fide

Associate

This should be the expected format:

$PSTMNMEAONOFF,<on_off>*<checksum><cr><lf>

Where is your checksum part?

F

Francesco Virlinzi

Technical Moderator

Hi

The idea is correct and it works.

I see two problem in the C:

static const char *NMEA_ON_OFF = "$PSTMNMEAONOFF,0\n\r";
static const char *gpgll_msg = "$PSTMGETRTCTIME\n\r";

should be replaced in

static const char *NMEA_ON_OFF = "$PSTMNMEAONOFF,0";

static const char *gpgll_msg = "$PSTMNMEAREQUEST, 0x100000,0x0";

char checksum(const char *string) {
 int i = 1, checksum = 0;
 for (i = 1; string[i] != '\0'; i++) {
 checksum ^= string[i];
 }
 return checksum;
}

and when you send the commands:

char str_checksum[6];
HAL_UART_Transmit(&huart1, *gpgll_msg, strlen(gpgll_msg), 1000);
sprintf(str_checksum, "*%02x\r\n", gpgll_msg, checksum(gpgll_msg));
HAL_UART_Transmit(&huart1, str_checksum, strlen(gpgll_msg), 5);

 
because you are not sending the checksum in the NMEA commands as the standard needs.
Regards
 Francesco

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