Any working sample code for stm32WLE5CC ?

vinodstanur · ‎2025-06-25

Hi everyone,

Is there any working sample code for STM32WLE5CC, specifically for basic LoRa TX (not LoRaWAN)?

I've been struggling for days — tried several STM32WL projects, but most don't compile or run properly on the STM32WLE5CC. Even examples from CubeMX seem inconsistent or poorly documented for this chip.

Is the STM32WLE5CC just not well supported, or am I missing something?

I’m using the MS23SF1 module (datasheet: MS23SF1 Datasheet), which integrates STM32WLE5CC with a 32 MHz crystal (not a TCXO). The module comes preloaded with some custom LoRaWAN firmware. They claim users can flash custom firmware using CubeMX IDE + their documentation — but I’ve had no luck getting the sub-GHz radio working.

Working so far:

LPUART
GPIO, clocks, basic peripheral bring-up

Not Working so far:

No working example of basic LoRa TX/RX
Difficult to configure radio manually
Cube-generated code does not transmit anything over RF

Has anyone successfully flashed bare LoRa code to STM32WLE5CC and gotten it to transmit? Any CubeIDE-compatible example project, HAL/LL-based code, or even direct register-level init would help.

Appreciate any guidance, tips, or links!

Thanks in advance.

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2025 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 "adc.h"
#include "dma.h"
#include "lptim.h"
#include "usart.h"
#include "rtc.h"
#include "subghz.h"
#include "gpio.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 */
void MX_SUBGHZ_Init(void);
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
extern SUBGHZ_HandleTypeDef hsubghz;

/* USER CODE BEGIN PV */

uint8_t payload[64] = "Hello World!";

uint8_t RadioParam[8]  = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
uint8_t interrupts[3] = {0};
uint8_t signal_delay = 100;
uint8_t uart_buff[65] = {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 */

  /* 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_SUBGHZ_Init();
  MX_LPUART1_UART_Init();
  MX_LPTIM1_Init();
  MX_ADC_Init();
  MX_RTC_Init();
  /* USER CODE BEGIN 2 */
//  MX_SUBGHZ_Init();
  // 1. Set Buffer Address
  RadioParam[0] = 0x80U; // Tx base address
  RadioParam[1] = 0x00U; // Rx base address

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_BUFFERBASEADDRESS, &RadioParam, 2) != HAL_OK)
  {
	  Error_Handler();
  }


  // 2. Write Payload to Buffer
  if (HAL_SUBGHZ_WriteBuffer(&hsubghz, 0x80U, &payload, sizeof(payload)) != HAL_OK)
  {
	  Error_Handler();
  }


  // 3. Set Packet Type
  RadioParam[0] = 0x01U; //LoRa packet type

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACKETTYPE, &RadioParam, 1) != HAL_OK)
  {
	  Error_Handler();
  }


  // 4. Set Frame Format
  RadioParam[0] = 0x00U; // PbLength MSB - 12-symbol-long preamble sequence
  RadioParam[1] = 0x0CU; // PbLength LSB - 12-symbol-long preamble sequence
  RadioParam[2] = 0x00U; // explicit header type
  RadioParam[3] = 0x40U; // 64 bit packet length.
  RadioParam[4] = 0x01U; // CRC enabled
  RadioParam[5] = 0x00U; // standard IQ setup

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACKETPARAMS, &RadioParam, 6) != HAL_OK)
  {
	  Error_Handler();
  }


  // 5. Define synchronisation word
  RadioParam[0] = 0x14U; // LoRa private network
  RadioParam[1] = 0x24U; // LoRa private network

  if (HAL_SUBGHZ_WriteRegisters(&hsubghz, (uint16_t) 0x740, &RadioParam, 2) != HAL_OK)
  {
	  Error_Handler();
  }


  // 6. Define RF Frequency
  RadioParam[0] = 0x33U; //RF frequency - 868000000Hz
  RadioParam[1] = 0xBCU; //RF frequency - 868000000Hz
  RadioParam[2] = 0xA1U; //RF frequency - 868000000Hz
  RadioParam[3] = 0x00U; //RF frequency - 868000000Hz

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_RFFREQUENCY, &RadioParam, 4) != HAL_OK)
  {
	  Error_Handler();
  }


  // 7. Set PA Config
  RadioParam[0] = 0x04U; // PaDutyCycle
  RadioParam[1] = 0x00U; // HpMax
  RadioParam[2] = 0x01U; // LP PA selected
  RadioParam[3] = 0x01U; // predefined in RM0461 and RM0453

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_PACONFIG, &RadioParam, 4) != HAL_OK)
  {
	  Error_Handler();
  }


  // 8.  Set Tx Parameters
  RadioParam[0] = 0x0EU; // Power - +14dB
  RadioParam[1] = 0x04U; // RampTime - 200us

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_TXPARAMS, &RadioParam, 2) != HAL_OK)
  {
	  Error_Handler();
  }


  // 9. Set Modulation parameter
  RadioParam[0] = 0x07U; // SF (Spreading factor) - 7 (default)
  RadioParam[1] = 0x09U; // BW (Bandwidth) - 20.83kHz
  RadioParam[2] = 0x01U; // CR (Forward error correction coding rate) - 4/5
  RadioParam[3] = 0x00U; // LDRO (Low data rate optimization) - off

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_MODULATIONPARAMS, &RadioParam, 4) != HAL_OK)
  {
	  Error_Handler();
  }


  // 10. Configure interrupts
  RadioParam[0] = 0x01U; // IRQ Mask MSB - Timeout interrupt
  RadioParam[1] = 0x01U; // IRQ Mask LSB - Tx done interrupt
  RadioParam[2] = 0x00U; // IRQ1 Line Mask MSB
  RadioParam[3] = 0x01U; // IRQ1 Line Mask LSB - Tx done interrupt on IRQ line 1
  RadioParam[4] = 0x01U; // IRQ2 Line Mask MSB - Timeout interrupt on IRQ line 2
  RadioParam[5] = 0x00U; // IRQ2 Line Mask LSB
  RadioParam[6] = 0x00U; // IRQ3 Line Mask MSB
  RadioParam[7] = 0x00U; // IRQ3 Line Mask LSB

  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_CFG_DIOIRQ, &RadioParam, 8) != HAL_OK)
  {
	  Error_Handler();
  }


  // 10.1 Read Interrupts
  if (HAL_SUBGHZ_ExecGetCmd(&hsubghz, RADIO_GET_IRQSTATUS, &interrupts, 3) != HAL_OK)
  {
	  Error_Handler();
  }

  sprintf(uart_buff, "Interrupts after set:  %i %i %i \n\r", interrupts[0], interrupts[1], interrupts[2]);
  //HAL_UART_Transmit(&huart1, (uint8_t *)uart_buff, sizeof(uart_buff), 100);
  //reset_uart_buff();




  // 11. Set Tx
  RadioParam[0] = 0x09U; // Timeout
  RadioParam[1] = 0xC4U; // Timeout
  RadioParam[2] = 0x00U; // Timeout
  GPIOA->ODR |= 1<<9;
  GPIOA->ODR &= ~( 1<<8 );



  // Check interrupts
  do
  {
	  if (HAL_SUBGHZ_ExecSetCmd(&hsubghz, RADIO_SET_TX, &RadioParam, 3) != HAL_OK)
	  {
		  Error_Handler();
	  }
	  if (HAL_SUBGHZ_ExecGetCmd(&hsubghz, RADIO_GET_IRQSTATUS, &interrupts, 3) != HAL_OK)
	  {
		  Error_Handler();
	  }

	  sprintf(uart_buff, "Interrupts after send: %i %i %i \n\r", interrupts[0], interrupts[1], interrupts[2]);
	  HAL_UART_Transmit(&hlpuart1, (uint8_t *)uart_buff, sizeof(uart_buff), 100);
	  //reset_uart_buff();

	 // HAL_Delay(2000);
  } while (1);

  /* 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 System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure LSE Drive Capability
  */
  HAL_PWR_EnableBkUpAccess();
  __HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);

  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_LSE
                              |RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
  RCC_OscInitStruct.LSIDiv = RCC_LSI_DIV1;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure the SYSCLKSource, HCLK, PCLK1 and PCLK2 clocks dividers
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK3|RCC_CLOCKTYPE_HCLK
                              |RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1
                              |RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.AHBCLK3Divider = RCC_SYSCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

/* 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.
  *   file: pointer to the source file name
  *   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 */