Data not being transmitted via USART on STM32H7B3I-DK

[JTurn.2]

What I am trying to do:

Send and receive data via USART on my STM32H7B3I-DK. I am connecting a serial USB to the STMod+ CN10 RX and TX and have 2 serial consoles on for monitoring the data that is transmitted on both ends (the serial USB and the discovery board).

What I have done:

I have generated a code with both USART1 and USART2 enabled. (USART1 for outputting the data that goes to the discovery board and USART2 to enable data transfer to the serial USB.) I then added a few lines of code (shown below) in the main loop to send and receive data.

I have also tried switching to USART3 on (CN11) but there is still no data being sent or received. I have also tried connecting to the ESP-01connector (CN4 of STMod+) , which should also be routed to USART2, but the result is the same.

Could someone provide me with some insight? Thank you for your help!

#include "main.h"
#include "stdio.h"
/* Private variables ---------------------------------------------------------*/
 
UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
void PeriphCommonClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);
static void MX_USART2_UART_Init(void);
 
int main(void)
{
 HAL_Init();
 SystemClock_Config();
 PeriphCommonClock_Config();
 MX_GPIO_Init();
 MX_RTC_Init();
 MX_USART1_UART_Init();
 MX_USART2_UART_Init();
 /* USER CODE BEGIN 2 */
	//USART_SendData(&huart2,"hi");
	uint8_t trans[] = "test"; //Data to send
	HAL_UART_Transmit(&huart2,trans,sizeof(trans),500);
	uint8_t recv[100]; //Data to send
	HAL_UART_Receive(&huart2,recv,sizeof(recv),500);
	HAL_UART_Transmit(&huart1,recv,sizeof(recv),500);
 /* USER CODE END 2 */
	
 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
 while (1)
 {
 /* USER CODE END WHILE */
 /* USER CODE BEGIN 3 */
 }
 /* USER CODE END 3 */
}
 
/**
 * @brief Peripherals Common Clock Configuration
 * @retval None
 */
void PeriphCommonClock_Config(void)
{
 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
 
 /** Initializes the peripherals clock
 */
 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_FMC|RCC_PERIPHCLK_OSPI
 |RCC_PERIPHCLK_CKPER;
 PeriphClkInitStruct.PLL2.PLL2M = 12;
 PeriphClkInitStruct.PLL2.PLL2N = 200;
 PeriphClkInitStruct.PLL2.PLL2P = 2;
 PeriphClkInitStruct.PLL2.PLL2Q = 2;
 PeriphClkInitStruct.PLL2.PLL2R = 4;
 PeriphClkInitStruct.PLL2.PLL2RGE = RCC_PLL2VCIRANGE_1;
 PeriphClkInitStruct.PLL2.PLL2VCOSEL = RCC_PLL2VCOWIDE;
 PeriphClkInitStruct.PLL2.PLL2FRACN = 0;
 PeriphClkInitStruct.FmcClockSelection = RCC_FMCCLKSOURCE_PLL2;
 PeriphClkInitStruct.OspiClockSelection = RCC_OSPICLKSOURCE_PLL2;
 PeriphClkInitStruct.CkperClockSelection = RCC_CLKPSOURCE_HSI;
 if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
 {
 Error_Handler();
 }
}
 
/**
 * @brief USART1 Initialization Function
 * @param None
 * @retval None
 */
static void MX_USART1_UART_Init(void)
{
 huart1.Instance = USART1;
 huart1.Init.BaudRate = 115200;
 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.Init.ClockPrescaler = UART_PRESCALER_DIV1;
 huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
 if (HAL_UART_Init(&huart1) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_SetTxFifoThreshold(&huart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_SetRxFifoThreshold(&huart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_DisableFifoMode(&huart1) != HAL_OK)
 {
 Error_Handler();
 }
 
}
 
static void MX_USART2_UART_Init(void)
{
 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.Init.ClockPrescaler = UART_PRESCALER_DIV1;
 huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
 if (HAL_UART_Init(&huart2) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_SetTxFifoThreshold(&huart2, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_SetRxFifoThreshold(&huart2, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_UARTEx_DisableFifoMode(&huart2) != HAL_OK)
 {
 Error_Handler();
 }
 
}
 
static void MX_GPIO_Init(void)
{
 GPIO_InitTypeDef GPIO_InitStruct = {0};
 
 /* GPIO Ports Clock Enable */
 __HAL_RCC_GPIOI_CLK_ENABLE();
 __HAL_RCC_GPIOG_CLK_ENABLE();
 __HAL_RCC_GPIOK_CLK_ENABLE();
 __HAL_RCC_GPIOD_CLK_ENABLE();
 __HAL_RCC_GPIOC_CLK_ENABLE();
 __HAL_RCC_GPIOE_CLK_ENABLE();
 __HAL_RCC_GPIOB_CLK_ENABLE();
 __HAL_RCC_GPIOJ_CLK_ENABLE();
 __HAL_RCC_GPIOA_CLK_ENABLE();
 __HAL_RCC_GPIOF_CLK_ENABLE();
 __HAL_RCC_GPIOH_CLK_ENABLE();
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOI, WIFI_BOOT_Pin|WIFI_WKUP_Pin|WIFI_RST_Pin, GPIO_PIN_RESET);
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOG, USER_LED1_Pin|USER_LED2_Pin, GPIO_PIN_RESET);
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(SPI2_NSS_GPIO_Port, SPI2_NSS_Pin, GPIO_PIN_RESET);
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(AUDIO_NRST_GPIO_Port, AUDIO_NRST_Pin, GPIO_PIN_SET);
 
 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOA, LCD_BL_CTRL_Pin|LCD_ON_OFF_Pin, GPIO_PIN_SET);
 
 /*Configure GPIO pins : WIFI_GPIO_Pin WIFI_DATRDY_Pin */
 GPIO_InitStruct.Pin = WIFI_GPIO_Pin|WIFI_DATRDY_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 HAL_GPIO_Init(GPIOI, &GPIO_InitStruct);
 
 /*Configure GPIO pins : SDIO1_D2_Pin SDIO1_CK_Pin SDIO1_D3_Pin SDIO1_D1_Pin
 SDIO1_D0_Pin */
 GPIO_InitStruct.Pin = SDIO1_D2_Pin|SDIO1_CK_Pin|SDIO1_D3_Pin|SDIO1_D1_Pin
 |SDIO1_D0_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 GPIO_InitStruct.Alternate = GPIO_AF12_SDMMC1;
 HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
 
 /*Configure GPIO pins : WIFI_BOOT_Pin WIFI_WKUP_Pin WIFI_RST_Pin */
 GPIO_InitStruct.Pin = WIFI_BOOT_Pin|WIFI_WKUP_Pin|WIFI_RST_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
 HAL_GPIO_Init(GPIOI, &GPIO_InitStruct);
 
 /*Configure GPIO pins : USER_LED1_Pin AUDIO_NRST_Pin USER_LED2_Pin */
 GPIO_InitStruct.Pin = USER_LED1_Pin|AUDIO_NRST_Pin|USER_LED2_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
 HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
 
 /*Configure GPIO pin : SDIO1_CMD_Pin */
 GPIO_InitStruct.Pin = SDIO1_CMD_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 GPIO_InitStruct.Alternate = GPIO_AF12_SDMMC1;
 HAL_GPIO_Init(SDIO1_CMD_GPIO_Port, &GPIO_InitStruct);
 
 /*Configure GPIO pin : uSD_Detect_Pin */
 GPIO_InitStruct.Pin = uSD_Detect_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
 GPIO_InitStruct.Pull = GPIO_PULLUP;
 HAL_GPIO_Init(uSD_Detect_GPIO_Port, &GPIO_InitStruct);
 
 /*Configure GPIO pins : SPI2_NSS_Pin LCD_BL_CTRL_Pin LCD_ON_OFF_Pin */
 GPIO_InitStruct.Pin = SPI2_NSS_Pin|LCD_BL_CTRL_Pin|LCD_ON_OFF_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 : WAKEUP_Pin */
 GPIO_InitStruct.Pin = WAKEUP_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 HAL_GPIO_Init(WAKEUP_GPIO_Port, &GPIO_InitStruct);
 
 /*Configure GPIO pin : MCO_Pin */
 GPIO_InitStruct.Pin = MCO_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
 GPIO_InitStruct.Alternate = GPIO_AF0_MCO;
 HAL_GPIO_Init(MCO_GPIO_Port, &GPIO_InitStruct);
 
 /*Configure GPIO pin : LCD_INT_Pin */
 GPIO_InitStruct.Pin = LCD_INT_Pin;
 GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 HAL_GPIO_Init(LCD_INT_GPIO_Port, &GPIO_InitStruct);
 
}

Note: I have shortened the code due to posting length limitations. Basically, my full code includes all of the settings STM32CUBEMX recommends turning on when generating a new code with this board with the exception of USART2 also being configured for serial input/output.

[TDK]

> USART1 for outputting the data that goes to the discovery board

Debug one thing at a time. Where is USART1 hooked up specifically? The user manual says it is used for the VCP, is this what you're monitoring?

How do you know it's not working? Are you looking a signals on the wires or are you just monitoring console output on your PC? Or something else?

[JTurn.2]

Hi, thank you for your reply. UASRT1 is hooked to the VCP which is outputted via CN14 (the USB STlink). It's not working cause there is nothing being outputted.

I just used a multi meter to test for a signal. I hooked up an esp8266 which outputs in serial and found that there is a voltage drop when there is data being transmitted. I then checked the data line (STM32 Tx on the STMod+ to Rx of the serial USB). There was no voltage drop. So I'm assuming there's no data being sent. I have also attached two pictures showing the output from the serial consoles. The top console is the STM32's serial while the bottom one is the output for the serial USB.

Note: I added a test string to UART1 to test that it's working properly

[JTurn.2]

Please ignore that the port for the top serial console is closed. I turned it off before I screenshot the images