HAL_UART_Receive() Polling Mode: Only picks up first character from UART
Hello,
I have a GPS module that prints of NMEA message strings in standard ASCII format at a rate of 9600 baud. This module is connected to usuart1 on my micro.
It appears that only the first character is ever caught by the system, and anything following that fails. Subsequent reads fail as well.
The GPS module has direct USB connection and I can see that 9600 baud with no parity and 1 stop bit is the correct configuration. My logic analyzer confirms this as well.
Does anyone know what might be causing this to occur?
Any help is much appreciated, thanks
Code with other functionality stripped out(filesystem stuff was stripped out for your reading)
/* Private variables ---------------------------------------------------------*/
RTC_HandleTypeDef hrtc;
SPI_HandleTypeDef hspi1;
SPI_HandleTypeDef hspi2;
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_RTC_Init(void);
static void MX_SPI1_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_SPI2_Init(void);
static void MX_USART1_UART_Init(void);
int main(void)
{
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_RTC_Init();
MX_SPI1_Init();
MX_USART2_UART_Init();
MX_SPI2_Init();
MX_FATFS_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
//uint8_t gpsBuff[10] = {0};
HAL_UART_Transmit(&huart2, (uint8_t*)"Hello There\r\n", sizeof("Hello There"), 1000);
uint8_t secondBuffer[100] = {0};
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
// Listen to GPS on uart1 and transmit received message to the Serial Terminal
HAL_UART_Receive(&huart1, secondBuffer, sizeof(secondBuffer), 1000);
HAL_UART_Transmit(&huart2, (uint8_t*)'\r\n', sizeof('\r\n'), 1000);
HAL_Delay(100);
HAL_UART_Transmit(&huart2, secondBuffer, sizeof(secondBuffer), 1000);
HAL_Delay(1000);
secondBuffer[0] = 0; //Seems strange but you'll see that only index 0 is being changed once, the rest remain zero and won't print
HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
}
}
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;
huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
if (HAL_UART_Init(&huart1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART1_Init 2 */
/* USER CODE END USART1_Init 2 */
}
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;
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 */
}CubeMX Setup for USUART1 (GPS UART)
Serial Terminal Capture (Occasionally when it first polls in the middle of the window it will publish a garbage character, but as you can see it only reads the first char, then prints only the new lines from the transmit, the buffer remains empty)
Serial Terminal Output when GPS connected directly to PC
Logic Analyzer Settings
Logic Analyzer Capture (This is what the HAL should receive, or at least some snippet of it)
