Problem at tweeting with ESP8266 via Thingspeak - twitter

Question

I programmed my ESP8266 to read the soil moisture. Depending on the moisture a water pump gets activated. Now I wanted the ESP to tweet different sentences, depending on the situation.
Therefore I connected my twitter account to thingspeak.com and followed this code
Connecting to the internet works fine.
Problems:
It does not tweet every time and if it tweets, only the first word from a sentence shows up at twitter.
According to the forum, where I found the code, I already tried to replace all the spaces between the words with "%20". However then nothing shows up at twitter at all. Also single words are not always posted to twitter.
This is the code I have problems with:
// if connection to thingspeak.com is successful, send your tweet!
if (client.connect("184.106.153.149", 80))
{
client.print("GET /apps/thingtweet/1/statuses/update?key=" + API + "&status=" + tweet + " HTTP/1.1\r\n");
client.print("Host: api.thingspeak.com\r\n");
client.print("Accept: */*\r\n");
client.print("User-Agent: Mozilla/4.0 (compatible; esp8266 Lua; Windows NT 5.1)\r\n");
client.print("\r\n");
Serial.println("tweeted " + tweet);
}
I don't get any error messages.
Maybe you could help me to make it visible if the tweet was really sent and how I manage to tweet a whole sentence.
I am using the Arduino IDE version 1.8.9 and I am uploading to this board
The rest of the code works fine. The only problem is the tweeting.
Update
I now tried a few different things:
Checking server response
Works and helps a lot. The results are:
Single words as String don't get any response at all
Same for Strings like "Test%20Tweet"
Strings with multiple words like "Test Tweet" get the following response and the first word of the String shows up as a tweet
HTTP/1.1 200 OK
Server: nginx/1.7.5
Date: Wed, 19 Jun 2019 18:44:22 GMT
Content-Type: text/html; charset=utf-8
Content-Length: 1
Connection: keep-alive
Status: 200 OK
X-Frame-Options: SAMEORIGIN
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS, DELETE, PATCH
Access-Control-Allow-Headers: origin, content-type, X-Requested-With
Access-Control-Max-Age: 1800
ETag: W/"RANDOM_CHARS"
Cache-Control: max-age=0, private, must-revalidate
X-Request-Id: THE_ID
1
I think the Content-Length might be the problem?
But I don't know how to change it in this code.
Checking if the connection succeded
I implemented this into my code an it never shows up on the monitor. So I think i never have a problem with not connecting.
Use a hostname instead of IP address
I tried it and never got a bad request. On the other hand nothing shows up on twitter at all.

Answer 1

Check if your tweet variable contains any new-line characters (carriage return or line feed). For example, the following variable would cause problems
String tweet = "Tweet no. 1\r\n";
due to the new-line characters at the end. These characters will cause the first line of the HTTP request to be cut short. I.e., instead of
GET /apps/thingtweet/1/statuses/update?key=api_key&status=Tweet no. 1 HTTP/1.1\r\n
it would become
GET /apps/thingtweet/1/statuses/update?key=api_key&status=Tweet no. 1\r\n
and the server would reject it with a 400 (Bad request) error.
On the other hand
String tweet = "Tweet no. 1";
would be fine.
If your tweets may contain such characters, then try encoding them before passing them to client.print():
tweet.replace("\r", "%0D");
tweet.replace("\n", "%0A");
Use a hostname instead of IP address
According to https://uk.mathworks.com/help/thingspeak/writedata.html, the relevant hostname for the API you are using is api.thingspeak.com. Use that instead of the IP address. This is preferable because the IP address a hostname points to can change regularly. (The IP address you are using doesn't even seem to be correct - and may already be out of date.)
I.e., change
if (client.connect("184.106.153.149", 80)) {
to
if (client.connect("api.thingspeak.com", 80)) {
API endpoint
Are you sure you are using the correct API endpoint? According to the link above, it looks like the API endpoint you need is https://api.thingspeak.com/update.json - so you may need to change
client.print("GET /apps/thingtweet/1/statuses/update?key=" + API + "&status=" + tweet + " HTTP/1.1\r\n");
to
client.print("GET /update.json?api_key=" + API + "&status=" + tweet + " HTTP/1.1\r\n");
Check if the connection succeeded
Presently, your device sends the HTTP request if connects to the server successfully - but doesn't give any indication if the connection fails! So add an else block to handle that scenario and notify the user via the serial console.
if (client.connect("api.thingspeak.com", 80)) {
client.print("GET /apps/thingtweet/1/statuses/update?key=" + API + "&status=" + tweet + " HTTP/1.1\r\n");
// etc.
}
else {
Serial.println("Connection to the server failed!");
}
Checking server response
To check the response from the server, add the following block to your main loop - which will print the server response via the serial console.
delay(50);
while (client.available()) {
String response_line = client.readString();
Serial.println(response_line);
}
To clarify: that code should go inside your loop() function.
The response should include a status line - such as HTTP/1.1 200 OK if the request was successful, or HTTP/1.1 400 Bad Request if there was a problem.
In the case of a Bad request response, the full message will quite likely contain more information about the precise reason the request failed.
HTTP vs HTTPs
Lastly, are you sure that the API supports (plain, unencrypted) HTTP as well as HTTPs? If not, that may be your problem.