ESP32 Forum

Posted: **Tue Feb 14, 2017 2:34 pm**

I'm implementing a user defined AT command but it makes the module reset

In at_task.c


static uint8_t at_exeCmdTest(uint8_t para_num)
{
	 int32_t cnt = 0;
	 uint8_t *str;
	 uint8_t *str2;

	if (para_num != 1) {
		return ESP_AT_RESULT_CODE_ERROR;
	}

	 str = (uint8_t *)malloc(32);
	 if (!str) {
		return ESP_AT_RESULT_CODE_ERROR;
	 }

	 str2 = (uint8_t *)malloc(10);
	 if (!str2) {
		free (str);
		return ESP_AT_RESULT_CODE_ERROR;
	 }

	if (esp_at_get_para_as_str (cnt++,&str2) != ESP_AT_PARA_PARSE_RESULT_OK) {
		free(str);
		free(str2);
		return ESP_AT_RESULT_CODE_ERROR;
	}

	sprintf((char*)str, "You've entered \"%s\"\r\n", str2);
	esp_at_port_write_data((uint8_t *)str, strlen( (char*)str));
	
	free(str);
	free(str2);

	esp_at_response_result(ESP_AT_RESULT_CODE_OK);

	return ESP_AT_RESULT_CODE_PROCESS_DONE;
}


static esp_at_cmd_struct at_custom_cmd[] = {
    {"+UART", NULL, NULL, at_setupCmdUart, NULL},
    {"+UART_CUR", NULL, NULL, at_setupCmdUart, NULL},
    {"+UART_DEF", NULL, NULL, at_setupCmdUartDef, NULL},
    {"+CIUPDATE", NULL, NULL, NULL, at_exeCmdCipupdate},
	{"+CITEST", NULL, NULL, at_exeCmdTest, NULL},
};

When I test it

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at+citest="123"<\r><\n>
You've entered "123"<\r><\n>
<\r><\n>
ready<\r><\n>

Why that happens? when I wrote other user defined AT commands with integer parameters or no parameters, this problem doesn't occur

Posted: **Sun Mar 04, 2018 8:19 pm**

Yet appears that you may be freeing esp_at lib's internal parameter buffer when you do:

Code: Select all

free(str2);

after:

Code: Select all

if (esp_at_get_para_as_str (cnt++,&str2) != ESP_AT_PARA_PARSE_RESULT_OK) {

Just get rid of all the malloc and free'ing for your str2. You could probably make some minor changes to not use sprintf, and get rid of all of the malloc() and free() calls in your example.

ESP32 Forum

User defined AT Command makes the module rest

User defined AT Command makes the module rest

Re: User defined AT Command makes the module rest