我正在编写一个程序以在ESP32(Arduino框架)中通过蓝牙接收SSID和密码。函数BTSerialRcvBuffer()等待蓝牙,当它接收到一个字符串时,它将通过struct Buffer_return类型的变量返回该字符串的基址和大小。该函数返回SSID,但不返回密码。不知道为什么我是否必须为Var.rtn_addr分配内存或为变量buff1和buff2分配足够的内存?
#include <Arduino.h>
#include <stdlib.h>
#include <BluetoothSerial.h>
#include <WiFi.h>
#define btrcv_buffer_size 256
BluetoothSerial SerialBT;
typedef struct
{
char *rtn_addr;
int buff_len;
} Buffer_return;
Buffer_return* BTSerialRcvBuffer() {
static int i = 0;
static char rcv_buffer[ btrcv_buffer_size ];
static Buffer_return Var;
memset(rcv_buffer,0, btrcv_buffer_size);
while (!SerialBT.available());
delayMicroseconds(500);
while(SerialBT.available()) {
rcv_buffer[i] = SerialBT.read();
i++;
}
rcv_buffer[i-1] = '\0';
rcv_buffer[i-2] = '\0';
SerialBT.flush();
Var.rtn_addr = rcv_buffer; //<------------Do I have to allocate memory for Var.rtn_addr?
Var.buff_len = i-1;
return &Var;
}
void WiFiConfig() {
//WiFi.printDiag(Serial);
Serial.println("Enter SSID");
Buffer_return *buff1 = BTSerialRcvBuffer();
char *ssid = (char*) malloc((buff1->buff_len) * sizeof(char));
strcpy(ssid,buff1->rtn_addr);
Serial.println(ssid);
Serial.println("Enter Password");
Buffer_return *buff2 = BTSerialRcvBuffer();
char *pass = (char*) malloc((buff2->buff_len) * sizeof(char));
strcpy(pass,buff2->rtn_addr);
Serial.println(pass);
//Serial.println(buff2->buff_len);
free(ssid)
free(pass);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Establishing connection to WiFi..");
Serial.printf("Connection status: %d\n", WiFi.status());
}
}
void setup() {
Serial.begin(115200);
//WiFi.disconnect(true);
SerialBT.begin("ESP32_INO"); //Bluetooth device name
WiFi.mode(WIFI_STA);
Serial.println("The device started, now you can pair it with bluetooth!");
WiFiConfig();
Serial.println("Connected to network");
Serial.println(WiFi.macAddress());
Serial.println(WiFi.localIP());
}
void loop() {
}
输出:
Enter SSID
Airtel_5G <----- prints fine!
Enter Password
<----- Problem!
Establishing connection to WiFi..
Connection status: 6
Establishing connection to WiFi..
Connection status: 6
Establishing connection to WiFi..
Connection status: 6
代码使用以下顺序将输入数据复制到缓冲区。
Buffer_return *buff1 = BTSerialRcvBuffer();
char *ssid = (char*) malloc((buff1->buff_len) * sizeof(char));
strcpy(ssid,buff1->rtn_addr);
请注意,字符串是NUL终止的,因此分配必须包括额外的字节!。对malloc调用的简单更新:
char *ssid = (char*) malloc((buff1->buff_len+1) * sizeof(char));
甚至更好,使用现有的strndup(我相信)>
char *ssid = strndup(buff1->rtn_addr, buff1->buff_len) ;
更新1:BTSerialRcvBuffer中的错误
BTSerialRcvBuffer
对许多变量使用静态,包括i
。回想一下,静态变量一次初始化(在程序启动时)。建议从i
中删除“ static”-修复初始化,因为不需要使其变为静态。
还不清楚为什么rcv_buffer
的最后2个位置重置为零?