How to make an API Call every second using ESP8266? - api

I tried making a HTTP request to my localhost that is running Laravel Api.
if (WiFi.status() == WL_CONNECTED) {
HTTPClient http;
http.begin(url + "update"); //request destination
http.addHeader("Content-Type", "application/x-www-form-urlencoded"); //content-type header
String stringData = "payload=" + data;
int httpCode = http.POST(stringData);
String payload = http.getString();
Serial.print(httpCode);
http.end();
}
delay(2000);
}
When I reduce delay value <= 2000, nodeMCU is not performing as expected.
While testing getting 429 error.
Please suggest an alternative that can update every second.

429 Too Many Requests "indicates the user has sent too many requests in a given amount of time". The server could be slow, or rate limited.
The server may send a Retry-After header; if it does, it tells you how long you have to wait before a new request is made.
I suspect you would have to change things on the server side to make it as fast as you want; I doubt the ESP8266 is to blame.
Note that if handling a request takes longer than 1s, you're out of luck anyway.
BTW could you try the code below and see if it works? Just to rule out some other potential problems. It removes the inefficient delay() and only does HTTPClient http; once.
HTTPClient http;
unsigned long int lastPost = 0;
int postInterval = 1000; // Post every second
void setup() {
// Setup stuffs
}
void loop() {
if (WiFi.status() == WL_CONNECTED && (millis() - lastPost) >= postInterval) {
http.begin(url + "update"); //request destination
http.addHeader("Content-Type", "application/x-www-form-urlencoded"); //content-type header
String stringData = "payload=" + data;
int httpCode = http.POST(stringData);
String payload = http.getString();
Serial.print(httpCode);
http.end();
lastPost = millis();
}
}
Untested, just typed it in, but you get the idea.

Related

Plc4x addressing system

I am discovering the Plc4x java implementation which seems to be of great interest in our field. But the youth of the project and the documentation makes us hesitate. I have been able to implement the basic hello world for reading out of our PLCs, but I was unable to write. I could not find how the addresses are handled and what the maskwrite, andMask and orMask fields mean.
Please can somebody explain to me the following example and detail how the addresses should be used?
#Test
void testWriteToPlc() {
// Establish a connection to the plc using the url provided as first argument
try( PlcConnection plcConnection = new PlcDriverManager().getConnection( "modbus:tcp://1.1.2.1" ) ){
// Create a new read request:
// - Give the single item requested the alias name "value"
var builder = plcConnection.writeRequestBuilder();
builder.addItem( "value-" + 1, "maskwrite:1[1]/2/3", 2 );
var writeRequest = builder.build();
LOGGER.info( "Synchronous request ..." );
var syncResponse = writeRequest.execute().get();
}catch(Exception e){
e.printStackTrace();
}
}
I have used PLC4x for writing using the modbus driver with success. Here is some sample code I am using:
public static void writePlc4x(ProtocolConnection connection, String registerName, byte[] writeRegister, int offset)
throws InterruptedException {
// modbus write works ok writing one record per request/item
int size = 1;
PlcWriteRequest.Builder writeBuilder = connection.writeRequestBuilder();
if (writeRegister.length == 2) {
writeBuilder.addItem(registerName, "register:" + offset + "[" + size + "]", writeRegister);
}
...
PlcWriteRequest request = writeBuilder.build();
request.execute().whenComplete((writeResponse, error) -> {
assertNotNull(writeResponse);
});
Thread.sleep((long) (sleepWait4Write * writeRegister.length * 1000));
}
In the case of modbus writing there is an issue regarding the return of the writer Future, but the write is done. In the modbus use case I don't need any mask stuff.

How to keep HTTP/2 connection alive till the request / response session is complete?

I am currently using HttpDeclarePushto exploit the Server Push feature in HTTP/2.
I am able to successfully create all the parameters that this function accepts. But the issue is when HttpDeclarePushexecutes it returns a value of 1229 (ERROR_CONNECTION_INVALID) - https://learn.microsoft.com/en-us/windows/desktop/debug/system-error-codes--1000-1299-.
On further investigation I found that the HttpHeaderConnection in _HTTP_HEADER_ID (https://learn.microsoft.com/en-us/windows/desktop/api/http/ne-http-_http_header_id) is actually passed in the function as 'close'. That implies that on every request response the server closes the connection and that is also happening in my case, I checked it in the log.
Here is the code.
class http2_native_module : public CHttpModule
{
public:
REQUEST_NOTIFICATION_STATUS OnBeginRequest(IN IHttpContext * p_http_context, IN IHttpEventProvider * p_provider)
{
HTTP_REQUEST_ID request_id;
const HTTPAPI_VERSION version = HTTPAPI_VERSION_2;
auto pHttpRequest = p_http_context->GetRequest();
auto phttpRequestRaw = pHttpRequest->GetRawHttpRequest();
HANDLE p_req_queue_handle = nullptr;
auto isHttp2 = phttpRequestRaw->Flags;
try {
const auto request_queue_handle = HttpCreateRequestQueue(version, nullptr, nullptr, NULL, &p_req_queue_handle);
const auto verb = phttpRequestRaw->Verb;
const auto http_path = L"/polyfills.0d74a55d0dbab6b8c32c.js"; //ITEM that I want to PUSH to client
const auto query = nullptr;
request_id = phttpRequestRaw->RequestId;
auto headers = phttpRequestRaw->Headers;
auto connId = phttpRequestRaw->ConnectionId;
WriteEventViewerLog(L"OnBeginRequest - Entering HTTPDECLAREPUSH");
headers.KnownHeaders[1].pRawValue = NULL;
headers.KnownHeaders[1].RawValueLength = 0;
const auto is_success = HttpDeclarePush(p_req_queue_handle, request_id, verb, http_path, query, &headers);
sprintf_s(szBuffer, "%lu", is_success);
Log("is_success value", szBuffer); //ERROR CODE 1229 here
HttpCloseRequestQueue(p_req_queue_handle);
}
catch (std::bad_alloc & e)
{
auto something = e;
}
return RQ_NOTIFICATION_CONTINUE;
}
I even tried to update the header connection value as below but it still gives me 1229.
headers.KnownHeaders[1].pRawValue = NULL;
headers.KnownHeaders[1].RawValueLength = 0;
I understand from https://http2.github.io/http2-spec/ that HTTP/2 actually ignores the content in HTTP HEADERs and uses some other mechanism as part of its FRAME.
This brings us to the next question on how we can keep the connection OPEN and is it something related to the FRAME (similar to HEADER) that HTTP2 uses, if so, how C++ or rather Microsoft helps us to play and exploit with the FRAME in HTTP2?

Global variable assigned inside while loop not available outside the loop

I'm calling an api using ESP8266 WiFi Chip. Im declaring a global variable to assign the token sent by the server to it. The variable assignment is made inside a while loop. In this loop i'm reading the contents of the reply "the token" and saving it in the global variable.
But when i print out the result outside the while loop to variable is empty. But inside the loop it is not.
String deviceToken;
WiFiClient client;
if (!client.connect(hostIp, 80)){
Serial.println("Connection to server failed.");
Serial.print(client.connect(hostIp, 80));
return;
}
String authURL = "/api/";
authURL += "startauth/";
authURL += serialValue;
Serial.print("Requesting URL: ");
Serial.println(authURL);
// This will send auth request to the server
client.print(String("GET ") + authURL + " HTTP/1.1\r\n" +
"Host: " + host + "\r\n" +
"Connection: close\r\n\r\n");
unsigned long timeout = millis();
while (client.available() == 0) {
if (millis() - timeout > 5000) {
Serial.println(">>> Client Timeout !");
client.stop();
return;
}
}
// Read Auth reply from server and print them to Serial
while(client.available()){
String token = client.readStringUntil('\r');
deviceToken = token;
writeDeviceToken(token.c_str()); //Function to write data in eeprom
Serial.print(deviceToken); //NOT EMPTY
}
Serial.print("Device Token:" + deviceToken); //EMPTY VARIABLE
In your while loop you are looping over the HTTP headers and the data line by line and overwrite deviceToken each time. This is ok, except that each line ends with \r\n and not only \r - (also, you probably only want to write the token to the eeprom, not every header).
So the last token that gets read is a single \n which is then put into deviceToken. You will need to read that extra byte after each line.
An alternative way would be to read until you reach \r\n\r\n (end of header block), then read the size (28 hex - this is a chunked transfer), and then you can read and store the token you want. Otherwise your token would be that last 0, or the newline following it.
Also keep in mind that there is no guarantee that the reply will allways be chunked (which is actually rather strange in this case), and you should be prepared for a 'normal' reply too.
An easy way to fix this, is to send a HTTP/1.0 request instead of HTTP/1.1 (as far as that server supports it). Since HTTP/1.0 doesn't support/allow chunked transfers you will always have a 'clean' deviceToken in the reply.
Thanks to Danny_ds instructions i was able to solve my issue and thought of sharing the working code in here as a reference.
// Read Auth reply from server and print them to Serial
while(client.available()){
char c = client.read();
response += c;
}
String testStatus = response;
if((strstr(testStatus.c_str(),"HTTP/1.1 500")) != NULL) {
Serial.println("Found reponse 500");
return;
} else if ((strstr(testStatus.c_str(),"HTTP/1.1 200")) != NULL) {
Serial.println("Found reponse 200");
//Grabing the token after the header
String token = response.substring(response.indexOf("\r\n\r\n") + 8 );
//Removing the \r in end of token
token.remove(40);
deviceToken = token;
writeDeviceToken(deviceToken.c_str());
delay(500);
Serial.print("Device Token:" + deviceToken);
return;
}

Issue with BTC-e API in App Script, method parameter

I am trying to incorporate the BTC-e.com API in to a google docs spreadsheet.
The API documentation is here: https://btc-e.com/api/documentation
The method name is sent via POST parameter method.
As the URLFetchApp requires me to set the type of request as POST by a parameter method and I then have another parameter called method to be set as getInfo.
How can I go about setting the fetch method as POST and have the API parameter method as getInfo.
Below is the function this relates too. Also I am sure there a more issues in my work I am yet to find.
function inventory() {
var nonce=Number(SpreadsheetApp.getActiveSheet().getRange('K2').getValue());
var token=SpreadsheetApp.getActiveSheet().getRange('K1').getValue();
var tokenEndpoint = "https://btc-e.com/tapi";
var sign= 'TEMP'
var head = {
'Content-Type': 'application/x-www-form-urlencoded',
'Key': token,
'Sign': sign
}
var params = {
method : "POST",
method : "getInfo",
headers: head,
contentType: 'application/x-www-form-urlencoded',
method : "getInfo",
nonce: nonce
}
var request = UrlFetchApp.getRequest(tokenEndpoint, params);
var response = UrlFetchApp.fetch(tokenEndpoint, params);
var response2=String(response);
SpreadsheetApp.getActiveSheet().getRange('K2').setValue(nonce+1);
SpreadsheetApp.getActiveSheet().getRange('I16').setValue(response2);
SpreadsheetApp.getActiveSheet().getRange('I17').setValue(nonce);
}
This just yields the error
Attribute provided with invalid value: method
Thanks,
Steve
PS: First time posting, I tried to get the format correct.
I made the following Google JavaScript function to do POST access to BTC-e. You can find this function in action in the example spreadsheet I made to demonstrate the BTC-e API functions.
function btceHttpPost(keyPair, method, params, nonce) {
if (keyPair === undefined) {
return "{'error':'missing key pair'}"
}
if (params === undefined) {
params = '';
}
// Cleanup keypair, remove all \s (any whitespace)
var keyPair = keyPair.replace(/[\s]/g, '');
// Keypair example: "AFE730YV-S9A4FXBJ-NQ12HXS9-CA3S3MPM-CKQLU0PG,96a00f086824ddfddd9085a5c32b8a7b225657ae2fe9c4483b4c109fab6bf1a7"
keyPair = keyPair.split(',');
var pubKey = keyPair[0];
var privKey = keyPair[1];
// As specified on the BTC-e api (https://btc-e.com/api/documentation) the
// nonce POST parameter must be an incrementing integer (>0). The easiest
// implementation is the use of a timestamp (TS), so there is no need
// for persistant storage. Preferable, the resolution of the TS should be
// small enough the handle the desired call-frequency (a sleep of the TS
// resolution can fix this but I don't like such a waste). Another
// consideration is the sizeof the nonce supported by BTC-e. Experiments
// revealed this is a 32 bit unsigned number. The native JavaScript TS,
// stored in a float, can be 53 bits and has a resolution of 1 ms.
if (nonce === undefined)
// This time stamp counts amount of 200ms ticks starting from Jan 1st, 2014 UTC
// On 22 Mar 2041 01:17:39 UTC, it will overflow the 32 bits and will fail
// the nonce key for BTC-e
var nonce = Math.floor((Date.now() - Date.UTC(2014,0)) / 200);
// Construct payload message
var msg = 'nonce=' + nonce + '&method=' + method + params;
var msgSign = Utilities.computeHmacSignature(Utilities.MacAlgorithm.HMAC_SHA_512, msg, privKey);
// Convert encoded message from byte[] to hex string
for (var msgSignHex = [], i = 0; i < msgSign.length; i++) {
// Doing it nibble by nibble makes sure we keep leading zero's
msgSignHex.push(((msgSign[i] >>> 4) & 0xF).toString(16));
msgSignHex.push((msgSign[i] & 0xF).toString(16));
}
msgSignHex = msgSignHex.join('');
var httpHeaders = {'Key': pubKey, 'Sign': msgSignHex};
var fetchOptions = {'method': 'post', 'headers': httpHeaders, 'payload': msg};
var reponse = UrlFetchApp.fetch('https://btc-e.com/tapi', fetchOptions);
return reponse.getContentText();
};
The problem looks to be with your params object . You have method set thrice in the same object, which is a source of confusion.
Next, take a look at the documentation for UrlFetchApp.fetch() ( https://developers.google.com/apps-script/reference/url-fetch/url-fetch-app#fetch(String,Object) ) . The method can take a value of post, get, delete, put.
The getInfo should probably be appended to your URL to make it
var tokenEndpoint = "https://btc-e.com/tapi/getInfo"
Per the docs, you also have to put in more parameters to the request, nonce, api key etc. Use this as a starting point, revisit the documentation and get back to SO if you still have trouble

why qtnetworkaccessmanager don't go to authenticationRequired

I am creating an application that is mentioned to connect to an instance of on owncloud server but i can't find why it doesn't connect to the server .Instead of that the reply i get to the login screen and i get the html code for it
this is the code responsible for the connection
//the network request and reply
QNetworkAccessManager * manager = new QNetworkAccessManager();
QUrl url (url1);
manager->get(QNetworkRequest(url));
connect(manager, SIGNAL(authenticationRequired(QNetworkReply*,QAuthenticator*)),
SLOT(provideAuthenication(QNetworkReply*,QAuthenticator*)));
connect(manager, SIGNAL(finished(QNetworkReply *)),
this, SLOT(result(QNetworkReply *)));
the reply code
void Login::result(QNetworkReply *reply)
{
reply->deleteLater();
if(reply->error() == QNetworkReply::NoError) {
// Get the http status code
int v = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
if (v >= 200 && v < 300) // Success
{
qDebug()<<"Here we got the final reply";
QString replyText = reply->readAll();
qDebug()<<replyText;
}
else if (v >= 300 && v < 400) // Redirection
{
qDebug()<<"Get the redirection url";
QUrl newUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute).toUrl();
// Because the redirection url can be relative,
// we have to use the previous one to resolve it
newUrl = reply->url().resolved(newUrl);
QNetworkAccessManager *manager = reply->manager();
QNetworkRequest redirection(newUrl);
QNetworkReply *newReply = manager->get(redirection);
QString replyText = newReply->readAll();
qDebug()<<replyText;
return; // to keep the manager for the next request
}
}
else
{
// Error
qDebug()<<reply->errorString();
}
reply->manager()->deleteLater();
}
could you help me figure out why i get the login screen instead of authentication ?
Try to call connect() before calling manager->get() otherwise when the authentication required signal is triggered, there might not be any slots present to call to handle that signal.
Try this instead:
QNetworkAccessManager * manager = new QNetworkAccessManager();
QUrl url (url1);
connect(manager, SIGNAL(authenticationRequired(QNetworkReply*,QAuthenticator*)),
SLOT(provideAuthenication(QNetworkReply*,QAuthenticator*)));
connect(manager, SIGNAL(finished(QNetworkReply *)),
this, SLOT(result(QNetworkReply *)));
manager->get(QNetworkRequest(url));