Fail to Retrieve channel description

Question

Asha Rani 2020-9-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/600307-fail-to-retrieve-channel-description

编辑： Vinod 2020-10-15

Serial.println("AT");

delay(1000);

Serial.print("AT+CIPSTART=3,\"TCP\",\"api.thingspeak.com\",80\r\n");

delay(3000);

Serial.print("AT+CIPSEND=3,");

Serial.print(68);

Serial.print("\r\n");

delay(2000);

Serial.print("GET /channels/");

Serial.print(channel_id);

Serial.print("/feeds.json?api_key=");

Serial.print(mystringchar);

Serial.print("&results=0 HTTP/1.1\r\n");

Serial.print("Host:");

Serial.print(DST_IP);

Serial.println(); //web link

delay(300);

unsigned long lastRead = millis();

while (millis() - lastRead < 5000) {

while (Serial.available())

{

if (Serial.find("description\":\""))

{

String message = Serial.readStringUntil('$');

Serial.flush();

Serial.println(message);

}

This code was working fine for our production since 3 years but presently we are unable to retrive description .please do suggest us .

we are using sim-800c and esp8266-12f

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Vinod 2020-9-28

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/600307-fail-to-retrieve-channel-description#answer_501391

Have you checked your GSM module to see that it still has data capacity? Nothing has changed on ThingSpeak early August that can be linked to what you are seeing.

Are you able to connect to any other site using the SIM-800C?

4 个评论
显示 2更早的评论隐藏 2更早的评论

Asha Rani 2020-10-8

yes i am able to read the data

Vinod 2020-10-8

Since the response is correct from POSTMAN and cURL, I suspect the issue is on your device code. I have pasted the Arduino sketch in my answer below that you can modify and try on your device.

请先登录，再进行评论。

Answer 2

Vinod 2020-10-5

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/600307-fail-to-retrieve-channel-description#answer_505641

编辑：Vinod 2020-10-5

在 MATLAB Online 中打开

Here's a working Arduino Sketch I have tried on an ESP32. It can be modified as needed for your device.

#include <WiFi.h>
const char* ssid = "YourSSIDHere";
const char* password = "YourWifiPasswordHere";
WiFiClient client;
const char* host = "api.thingspeak.com";
void setup() {
  Serial.begin(115200);
  delay(100);
  WiFi.begin(ssid, password);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");  
}
void loop() {
  delay(5000);
  if (!client.connect(host, 80)) {
    Serial.println("connection failed");
    return;
  }
  
  String url = "/channels/366768/feeds.json?api_key=DoesNotMatter&results=0&headers=false";
  Serial.print("Requesting URL: ");
  Serial.println(url);
  
  client.print(String("GET ") + url + " HTTP/1.1\r\n" +
               "Host: " + host + "\r\n" + 
               "Connection: close\r\n\r\n");
  delay(500);
  
  while(client.available()){
      String line = client.readStringUntil('{');
      line = client.readStringUntil('}');
      Serial.print(line);
      while(client.available()){client.readStringUntil('\r');}
      Serial.print("\r\n");
  }
  delay(10000);
}

2 个评论
显示无隐藏无

Asha Rani 2020-10-11

we are using ESP-8266 without the WiFi shield in the productionand the device has been working fine in the field but now we are facing issue for new production.

Vinod 2020-10-15

编辑：Vinod 2020-10-15

If existing devices are working fine but new production devices are not, I would suggest looking at what might be different on the new devices. It could be that one of the libraries you use has changed, or something about the hardware (available memory, memory partitions, etc.?) has changed causing you to see different results.

请先登录，再进行评论。