How to read data from ThingSpeak and control led using sim800L?

I'm working on SIM800L with arduino and try to read data from ThingSpeak. I can read my channel field last value (1 or 0) using AT+HTTPREAD command. But the content get from sim800L.read() is -1 not one or zero. I want to read 1 or 0 and then turn on/off LED. How to get the data of field from the response of AT+HTTPREAD? Please find the code as follows:

{.....

SIM800L.println("AT+HTTPPARA=\"URL\",\"http://api.thingspeak.com/channels/xxxxxxx/fields/3/last?api_key=xxxxxxxxxxxxxx\"");

delay(1000);

ShowSerialData();

SIM800L.println("AT+HTTPACTION=0");

delay(10000);

ShowSerialData();

SIM800L.println("AT+HTTPREAD");

delay(300);

ShowSerialData();

changeled();

ShowSerialData();

SIM800L.println("");

delay(100);

}

void changeled()

{

String content = "";

Serial.println(SIM800L.read());

content = content + String(SIM800L.read());

Serial.print("Content:");

Serial.println(content);

}

[Severin Baumgartner]

Hello, I have the same problem. How did you finally solve the problem? I would be very happy about help. I despair: D

greetings from Germany

[Christopher Stapels]

-1 is for unauthorized. Perhaps it is a private channel you are trying to read?

[Anzaku Engla]

First of all you have to be sure you can read AT command reply from the SIM800 first. If you can do this your solution is close

Answer 1

[Vinod]

Is the SIM card activated? Have you confirmed that you can connect to the internet with the SIM800L module and your SIM card? Does your GSM provider support the use of their SIM card in the SIM800L module? See this video.