How to send AT commands in Keil - c

Question

I am using HC-05 bluetooth module and STM32F407. I am trying to change the name of the bluetooth module. I can enter AT Command Mode, but i can't send any AT Commands to module. I tried something in main. But it didn't work
I see
huart->Instance->DR = (*pData++ & (uint8_t)0xFF);
in my Transmit function. Also, i see ascii values of elements in DR
Here is my try.
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "string.h"
/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart3;
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_USART3_UART_Init();
/* USER CODE BEGIN 2 */
char* data = "AT+NAME=charles \n\r";
HAL_UART_Transmit(&huart3, (uint8_t *)data, strlen(data), 2000);
/* USER CODE END 2 */
while (1)
{
}
}
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_SCALE1);
/** Initializes the CPU, AHB and APB busses clocks
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB busses 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_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
static void MX_USART3_UART_Init(void)
{
huart3.Instance = USART3;
huart3.Init.BaudRate = 38400;
huart3.Init.WordLength = UART_WORDLENGTH_8B;
huart3.Init.StopBits = UART_STOPBITS_1;
huart3.Init.Parity = UART_PARITY_NONE;
huart3.Init.Mode = UART_MODE_TX_RX;
huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart3.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart3) != HAL_OK)
{
Error_Handler();
}
}
static void MX_GPIO_Init(void)
{
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOB_CLK_ENABLE();
}
[1]: https://i.stack.imgur.com/pbxqx.png

Answer 1

If you want to send a character buffer:
static void MX_USART3_UART_Init(void)
{
char* data = "AT+NAME=charles \n\r";
HAL_UART_Transmit(&huart3, (uint8_t *)data, strlen(data), 2000);
}
That's all you need. You called sprintf as if it was strcpy and the first argument is an uninitialized character buffer.

Answer 2

as tadman said, you don't need this:
uint8_t data[50];
But this is not a uninitialized character buffer as tadman said.