Unable to upload the data on thingspeak using uno and esp8266

Question

I am able to connect to thingspeak but now able to upload the data. here are my set of commands:

AT+CIPMUX=0
OK

AT+CIPSTART="TCP","184.106.153.149", 80   
OK
Linked

AT+CIPSTATUS
STATUS:3
+CIPSTATUS:0,"TCP","184.106.153.149",80,0
OK

AT+CIPSEND=45    
> GET /update?api_key=DXDPC4MLXMXFB5TT&field1=60

busy s...

SEND OK

OK

and after some time unlink

I am giving these commands using arudino serial monitor. Please help, I have searched a many blogs, youtube videos.

Answer 1

You have a malformed HTTP request. You only have half of the first line.

A valid HTTP request would look more like this:

GET /update?api_key=DXDPC4MLXMXFB5TT&field1=60 HTTP/1.1
Host: api.thingspeak.com
Content-length: 0
Connection: close
<blank line>

Just sending "GET : ain't gonna work. For a start, the server won't know what protocol you're speaking (HTTP/1.1), nor what website it's supposed to direct the request to (Host: api.thingspeak.com). Also, the final extra blank line is required to finish the request.

Answer 2

I got it working. Yo!

#include <SoftwareSerial.h>
#include <stdlib.h>

// LED
int ledPin = 13;
// LM35 analog input
int lm35Pin = 0;
float my_value = 22;
// replace with your channel's thingspeak API key
String apiKey = "9PJEF1EP8ZMVY5JA";

// connect 10 to TX of Serial USB
// connect 11 to RX of serial USB
SoftwareSerial ser(10, 11); // RX, TX

// this runs once
void setup() {                
  // initialize the digital pin as an output.
  pinMode(ledPin, OUTPUT);    

  // enable debug serial
  Serial.begin(9600);
  // enable software serial
  ser.begin(9600);

  // reset ESP8266
  ser.println("AT+RST");
}


// the loop
void loop() {

  // blink LED on board
  digitalWrite(ledPin, HIGH);   
  delay(200);               
  digitalWrite(ledPin, LOW);

  // read the value from LM35.
  // read 10 values for averaging.


  // convert to temp:
  // temp value is in 0-1023 range
  // LM35 outputs 10mV/degree C. ie, 1 Volt => 100 degrees C
  // So Temp = (avg_val/1023)*5 Volts * 100 degrees/Volt
  my_value++;
  float temp = my_value;

  // convert to string
  char buf[16];
  String strTemp = dtostrf(temp, 4, 1, buf);

  Serial.println(strTemp);

  // TCP connection
  String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += "184.106.153.149"; // api.thingspeak.com
  cmd += "\",80";
  ser.println(cmd);

  if(ser.find("Error")){
    Serial.println("AT+CIPSTART error");
    return;
  }

  // prepare GET string
  String getStr = "GET /update?api_key=";
  getStr += apiKey;
  getStr +="&field1=";
  getStr += String(strTemp);
  getStr +="&field2=";
  getStr += String(strTemp);
  getStr += "\r\n\r\n";

  // send data length
  cmd = "AT+CIPSEND=";
  cmd += String(getStr.length());
  ser.println(cmd);
  Serial.println(cmd);

  if(ser.find(">")){
    ser.print(getStr);
    Serial.println(getStr);
  }
  else{
    ser.println("AT+CIPCLOSE");
    // alert user
    Serial.println("AT+CIPCLOSE");
  }

  // thingspeak needs 15 sec delay between updates
  ser.println("AT+RST");
  delay(30000);  
}