How to implement USB-CDC functionality for B L072Z LRWAN1 discovery kit

you can find not similar but project for another controller on your IDE folder

Ya followed that but still facing problem. Till now i have tried following things:-

• Changed the clock source on the hardware board, made it to TCXO source now. After changing it is working in debug mode and my clock configuration is

 /* Enable HSI Oscillator to be used as System clock source
 Enable HSI48 Oscillator to be used as USB clock source */
 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSI48;
 RCC_OscInitStruct.HSIState = RCC_HSI_ON;
 RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
 HAL_RCC_OscConfig(&RCC_OscInitStruct);
 
 /* Select HSI48 as USB clock source */
 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
 PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
 HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
 
 /* Select HSI as system clock source and configure the HCLK, PCLK1 and PCLK2
 clock dividers */
 RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
 RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
 RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
 RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);
 
 /*Configure the clock recovery system (CRS)**********************************/
 
 /*Enable CRS Clock*/
 __HAL_RCC_CRS_CLK_ENABLE();
 
 /* Default Synchro Signal division factor (not divided) */
 RCC_CRSInitStruct.Prescaler = RCC_CRS_SYNC_DIV1;
 /* Set the SYNCSRC[1:0] bits according to CRS_Source value */
 RCC_CRSInitStruct.Source = RCC_CRS_SYNC_SOURCE_USB;
 /* HSI48 is synchronized with USB SOF at 1KHz rate */
 RCC_CRSInitStruct.ReloadValue = __HAL_RCC_CRS_RELOADVALUE_CALCULATE(48000000, 1000);
 RCC_CRSInitStruct.ErrorLimitValue = RCC_CRS_ERRORLIMIT_DEFAULT;
 /* Set the TRIM[5:0] to the default value*/
 RCC_CRSInitStruct.HSI48CalibrationValue = 0x20;
 /* Start automatic synchronization */
 HAL_RCCEx_CRSConfig (&RCC_CRSInitStruct);

• With the same clock configuration when i flash the code and put BOOT0 pin = 0, then Virtual com port is not creating.

I've had the USB working on the Murata modules, for the DISCO board I recall there being Solder Bridges (SB) that you must attend too. Review schematic/user manual.

Hello,

I intend to add USB CDC feature on the current PING PONG project on my B-L072Z-LRWAN board.

First I did the solder bridges configurations presented on this thread.

Then, I created a simple STM32Cube project for this board, configuring USB CDC. It worked correctly. But it doesn't have the LoraWan stack and porting it to a Cube Project is not a simple task (I tried it, without success). But, I could see USB CDC working.

To add USB CDC on the PingPong project, I got the project from STM32L073Z_EVAL and added the features to PingPong project. But it is not working. My PC cannot recognize the USB port.

I set 0x1000 heap size at linker script.

Below my system clock configuration:

void SystemClock_Config(void)
{
 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
 RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
 
 /* Enable HSE Oscillator and Activate PLL with HSE as source */
 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
 RCC_OscInitStruct.HSEState = RCC_HSE_OFF;
 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.PLLMUL = RCC_PLLMUL_6;
 RCC_OscInitStruct.PLL.PLLDIV = RCC_PLLDIV_3;
 
 if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
 {
 Error_Handler();
 }
 
 /*Select PLL 48 MHz output as USB clock source */
 PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
 PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_PLL;
 HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
 
 /* Set Voltage scale1 as MCU will run at 32MHz */
 __HAL_RCC_PWR_CLK_ENABLE();
 __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
 
 /* Poll VOSF bit of in PWR_CSR. Wait until it is reset to 0 */
 while (__HAL_PWR_GET_FLAG(PWR_FLAG_VOS) != RESET) {};
 
 /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
 clocks dividers */
 RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
 RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
 RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
 RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
 {
 Error_Handler();
 }
}

Could you please advise me where am I doing wrong ... or how should I debug my implementation?]

Best regards,

Flavio

Solder the connections SB16 and SB15, by default board comes with open line USB_DM and USB_DP. Once you short SB16 and SB15 you will find another virtual com port.