Problem whit STM32F401RE as USB HID Device when using ADC

[pablin235]

Hi, i'm using my Nucleo STM32F401RE as a HID Device for a MIDI Keyboard project

I have configured the following:

Connectivity --> USB_OTG_FS --> Device Only

Middleware --> USB_DEVICE --> Human Interface Device

I followed a video tutorial to configure the USB MIDI Descriptor in the file usbd_hid.c and it worked, my notebook detects my Nucleo as a USB Device and I have made a code to send only MIDI Note On and Note Off messages up to now, when pushing the Nucleo switch.

The problem comes when trying to use a potentiometer to send Control Change messages. I tried to use the ADC with interrupt and with DMA but when i use it, my notebook fails to detect the board as a USB

If i comment the line that initializes the ADC (HAL_ADC_Start_DMA) it works, but when uncommenting it again the ADC works fine but the HID doesn't

I'm not sure if i have an issue with the configuration of the ADC or USB or if maybe they are incompatible

The code in the main.c is the following:

/* USER CODE BEGIN Header */

/**

 ******************************************************************************

 * @file : main.c

 * @brief : Main program body

 ******************************************************************************

 * @attention

 *

 * Copyright (c) 2024 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"

#include "usb_device.h"



/* Private includes ----------------------------------------------------------*/

/* USER CODE BEGIN Includes */

#include "usbd_hid.h"

/* 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 ---------------------------------------------------------*/

ADC_HandleTypeDef hadc1;

DMA_HandleTypeDef hdma_adc1;



/* USER CODE BEGIN PV */

extern USBD_HandleTypeDef hUsbDeviceFS;



//MIDI Message arrays: 4 Bytes

uint8_t midiNoteOn[4];

uint8_t midiNoteOff[4];



uint8_t botonEstadoActual = 0;

uint8_t botonEstadoAnterior = 0;

uint8_t botonTimeOut = 10;



uint8_t lastDebounceTime = 0;

uint8_t botonTimer = 0;



uint16_t adc_val = 0;

uint32_t buffer = 0;



/* USER CODE END PV */



/* Private function prototypes -----------------------------------------------*/

void SystemClock_Config(void);

static void MX_GPIO_Init(void);

static void MX_DMA_Init(void);

static void MX_ADC1_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 */

//NOTE ON MESSAGE

//Header Byte (Solo para MIDI USB)

 midiNoteOn[0] = 0x09; //Cable Number 0 (puede ser de 0 a F), el 9 es el Codigo (CIN) de NoteOn

//Status Byte (El primer Nibble es el comando (NoteOn) y el segundo el Canal

 midiNoteOn[1] = 0x90; //9 es para NoteOn y 0 es el Canal 0

//Data Byte 1 --> Es el numero de nota, valor entre 0 y 127 pues el MSB de un data byte siempre es 0

 midiNoteOn[2] = 0x40; //0x40 es 64

//Data Byte 2 --> Es la velocidad, la dejamos en un valor constante por no medirla

 midiNoteOn[3] = 0x7F; //0x7F es 127, ponemos el maximo



//NOTE OFF MESSAGE

//Header Byte (Solo para MIDI USB)

 midiNoteOff[0] = 0x08; //Cable Number 0 (puede ser de 0 a F), el 8 es el Codigo (CIN) de NoteOff

//Status Byte (El primer Nibble es el comando (NoteOn) y el segundo el Canal

 midiNoteOff[1] = 0x80; //8 es para NoteOff y 0 es el Canal 0

//Data Byte 1 --> Es el numero de nota, valor entre 0 y 127 pues el MSB de un data byte siempre es 0

 midiNoteOff[2] = 0x40; //0x40 es 64

//Data Byte 2 --> Es la velocidad, la dejamos en un valor constante por no medirla

 midiNoteOff[3] = 0x7F; //0x7F es 127, ponemos el maximo



uint8_t retorno = 0;



/* 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_DMA_Init();

 MX_USB_DEVICE_Init();

 MX_ADC1_Init();

/* USER CODE BEGIN 2 */

HAL_ADC_Start_DMA(&hadc1, &buffer, 1);

/* USER CODE END 2 */



/* Infinite loop */

/* USER CODE BEGIN WHILE */

while (1)

 {

/* USER CODE END WHILE */



/* USER CODE BEGIN 3 */

 botonEstadoActual = HAL_GPIO_ReadPin(Boton_GPIO_Port, Boton_Pin);

 botonTimer = HAL_GetTick() - lastDebounceTime;

if(botonTimer > botonTimeOut)

 {

if(botonEstadoActual != botonEstadoAnterior)

 {

 lastDebounceTime = HAL_GetTick();

if(botonEstadoActual == 0)

 {

//midiNoteOn[2] = (buffer*127)/4096;

//midiNoteOff[2] = (buffer*127)/4096;

while(((USBD_HID_HandleTypeDef *)hUsbDeviceFS.pClassData)->state==USBD_HID_BUSY)

 {

 }

 retorno = USBD_HID_SendReport(&hUsbDeviceFS,midiNoteOn,4);

if(retorno == 0)

 HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_SET);

 }

else

 {

while(((USBD_HID_HandleTypeDef *)hUsbDeviceFS.pClassData)->state==USBD_HID_BUSY)

 {

 }

 retorno = USBD_HID_SendReport(&hUsbDeviceFS,midiNoteOff,4);

if(retorno == 0)

 HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);

 }

 botonEstadoAnterior = botonEstadoActual;

 }

 }

 }

/* 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_OSCILLATORTYPE_HSE;

 RCC_OscInitStruct.HSEState = RCC_HSE_ON;

 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_HSE;

 RCC_OscInitStruct.PLL.PLLM = 4;

 RCC_OscInitStruct.PLL.PLLN = 72;

 RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;

 RCC_OscInitStruct.PLL.PLLQ = 3;

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_HSI;

 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_0) != HAL_OK)

 {

 Error_Handler();

 }

}



/**

 * @brief ADC1 Initialization Function

 * @PAram None

 * @retval None

 */

static void MX_ADC1_Init(void)

{



/* USER CODE BEGIN ADC1_Init 0 */



/* USER CODE END ADC1_Init 0 */



ADC_ChannelConfTypeDef sConfig = {0};



/* USER CODE BEGIN ADC1_Init 1 */



/* USER CODE END ADC1_Init 1 */



/** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)

 */

 hadc1.Instance = ADC1;

 hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;

 hadc1.Init.Resolution = ADC_RESOLUTION_12B;

 hadc1.Init.ScanConvMode = ENABLE;

 hadc1.Init.ContinuousConvMode = ENABLE;

 hadc1.Init.DiscontinuousConvMode = DISABLE;

 hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;

 hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;

 hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;

 hadc1.Init.NbrOfConversion = 1;

 hadc1.Init.DMAContinuousRequests = ENABLE;

 hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;

if (HAL_ADC_Init(&hadc1) != HAL_OK)

 {

 Error_Handler();

 }



/** Configure for the selected ADC regular channel its corresponding rank in the sequencer and its sample time.

 */

 sConfig.Channel = ADC_CHANNEL_0;

 sConfig.Rank = 1;

 sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;

if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)

 {

 Error_Handler();

 }

/* USER CODE BEGIN ADC1_Init 2 */



/* USER CODE END ADC1_Init 2 */



}



/**

 * Enable DMA controller clock

 */

static void MX_DMA_Init(void)

{



/* DMA controller clock enable */

 __HAL_RCC_DMA2_CLK_ENABLE();



/* DMA interrupt init */

/* DMA2_Stream0_IRQn interrupt configuration */

 HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 0, 0);

 HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);



}



/**

 * @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_GPIOC_CLK_ENABLE();

 __HAL_RCC_GPIOH_CLK_ENABLE();

 __HAL_RCC_GPIOA_CLK_ENABLE();

 __HAL_RCC_GPIOB_CLK_ENABLE();



/*Configure GPIO pin Output Level */

 HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);



/*Configure GPIO pin : Boton_Pin */

 GPIO_InitStruct.Pin = Boton_Pin;

 GPIO_InitStruct.Mode = GPIO_MODE_INPUT;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 HAL_GPIO_Init(Boton_GPIO_Port, &GPIO_InitStruct);



/*Configure GPIO pins : USART_TX_Pin USART_RX_Pin */

 GPIO_InitStruct.Pin = USART_TX_Pin|USART_RX_Pin;

 GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 GPIO_InitStruct.Alternate = GPIO_AF7_USART2;

 HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);



/*Configure GPIO pin : LD2_Pin */

 GPIO_InitStruct.Pin = LD2_Pin;

 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;

 GPIO_InitStruct.Pull = GPIO_NOPULL;

 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

 HAL_GPIO_Init(LD2_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 hope someone can give me a hand!

Thank you!

[TDK · Accepted solution]

>  sConfig.SamplingTime = ADC_SAMPLETIME_3CYCLES;

You're swamping the system with ADC interrupts so the USB doesn't have time to respond. Increase the sampling time to max and/or increase the number of samples you take before calling the ADC half/complete callbacks.

[pablin235]

Hi TDK!

Thank you so much, it worked!

It's my first time working with USB so I wasn't aware that a high sampling frequency could affect the USB response

Greetings!