我想使用 sim900a 模块和 arduino uno 通过短信将 GPS 坐标发送到特定号码,当他们从短信(如"发送 GPS"(请求时,这里编写了代码,但是当我编译代码时,我收到"错误:请求从'void'转换为非标量类型'字符串'".....请任何帮助不胜感激...提前谢谢你
void loop() {
RecieveMessage();
if (sim.available() > 0)
{
Serial.write(sim.read());
}
if(sim.read()=="SEND GPS")
{
SendMessage();
}
}
void RecieveMessage()
{
Serial.println ("SIM800L Read an SMS");
sim.println("AT+CNMI=2,2,0,0,0");
Serial.write ("Unread Message done");
}
void SendMessage()
{
//Serial.println ("Sending Message");
sim.println("AT+CMGF=1");
sim.println("AT+CMGS="" + number + ""r");
while (sgps.available())
{
int c = sgps.read();
if (gps.encode(c))
{
float slat,slon;
String loc=gps.f_get_position(&slat, &slon);
}
String SMS = String("http://maps.google.com/maps?q=loc:")+String(loc);
sim.println(SMS);
sim.println((char)26);
}
gps.f_get_position
返回 void,但您正在将其分配给String
。只需删除String loc=
void loop()
{
while (sgps.available())
{
int c = sgps.read();
if (gps.encode(c))
{
float slat,slon;
gps.f_get_position(&slat, &slon);
Serial.print("Latitude :");
Serial.println(slat, 6);
Serial.print("Longitude:");
Serial.println(slon, 6);
String loc = String(slat,6)+" "+String(slon,6);
Serial.println ("Sending Message");
sim.println("AT+CMGF=1"); //Sets the GSM Module in Text Mode
delay(1000);
Serial.println ("Set SMS Number");
sim.println("AT+CMGS="" + number + ""r"); //Mobile phone number to send message
delay(1000);
String SMS = String("https://www.google.com/maps/") + String(slat,6)+","+String(slon,6);
sim.println(SMS);
delay(100);
sim.println((char)26);// ASCII code of CTRL+Z
delay(1000);
_buffer = _readSerial();
}
}
}