I tried to do a RFID card reading with the esp8266. But when I upload the code it's got an error. Can you help me? Here's a part of the code:
void loop() {
// put your main code here, to run repeatedly
readsuccess = getid();
if(readsuccess) {
digitalWrite(ON_Board_LED, LOW);
HTTPClient http; //Declare object of class HTTPClient
String UIDresultSend, postData;
UIDresultSend = StrUID;
//Post Data
postData = "UIDresult=" + UIDresultSend;
http.begin("http://IPaddress/NodeMCU_RC522_Mysql/getUID.php");
http.addHeader("Content-Type", "application/x-www-form-urlencoded");
int httpCode = http.POST(postData); //Send the request
String payload = http.getString(); //Get the response payload
Serial.println(UIDresultSend);
Serial.println(httpCode); //Print HTTP return code
Serial.println(payload); //Print request response payload
http.end(); //Close connection
delay(1000);
digitalWrite(ON_Board_LED, HIGH);
}
}
This error occurs in latest version of ESP8266 board.
Go to Tools >> Board >> Board Manager >> install 2.7.4 version of esp8266 board. That's it! It will fix this error.
Refer this video on how to downgrade board version: https://www.youtube.com/watch?v=m3Xb9GB9SI8
Thanks
Related
I'm trying to send multiple packets at once to a server, but the socket keeps "merging" all sync calls to write as a single call, I did a minimal reproducible example:
import 'dart:io';
void main() async {
// <Server-side> Create server in the local network at port <any available port>.
final ServerSocket server =
await ServerSocket.bind(InternetAddress.anyIPv4, 0);
server.listen((Socket client) {
int i = 1;
client.map(String.fromCharCodes).listen((String message) {
print('Got a new message (${i++}): $message');
});
});
// <Client-side> Connects to the server.
final Socket socket = await Socket.connect('localhost', server.port);
socket.write('Hi World');
socket.write('Hello World');
}
The result is:
> dart example.dart
> Got a new message (1): Hi WorldHello World
What I expect is:
> dart example.dart
> Got a new message (1): Hi World
> Got a new message (2): Hello World
Unfortunately dart.dev doesn't support dart:io library, so you need to run in your machine to see it working.
But in summary:
It creates a new tcp server at a random port.
Then creates a socket that connects to the previous created server.
The socket makes 2 synchronous calls to the write method.
The server only receives 1 call, which is the 2 messages concatenated.
Do we have some way to receive each synchronous write call in the server as separated packets instead buffering all sync calls into a single packet?
What I've already tried:
Using socket.setOption(SocketOption.tcpNoDelay, true); right after Socket.connect instantiation, this does modify the result:
final Socket socket = await Socket.connect('localhost', server.port);
socket.setOption(SocketOption.tcpNoDelay, true);
// ...
Using socket.add('Hi World'.codeUnits); instead of socket.write(...), also does not modify the result as expected, because write(...) seems to be just a short version add(...):
socket.add('Hi World'.codeUnits);
socket.add('Hello World'.codeUnits);
Side note:
Adding an async delay to avoid calling write synchronously:
socket.add('Hi World'.codeUnits);
await Future<void>.delayed(const Duration(milliseconds: 100));
socket.add('Hello World'.codeUnits);
make it works, but I am pretty sure this is not the right solution, and this isn't what I wanted.
Environment:
Dart SDK version: 2.18.4 (stable) (Tue Nov 1 15:15:07 2022 +0000) on "windows_x64"
This is a Dart-only environment, there is no Flutter attached to the workspace.
As Jeremy said:
Programmers coding directly to the TCP API have to implement this logic themselves (e.g. by prepending a fixed-length message-byte-count field to each of their application-level messages, and adding logic to the receiving program to parse these byte-count fields, read in that many additional bytes, and then present those bytes together to the next level of logic).
So I chose to:
Prefix each message with a - and suffix with ..
Use base64 to encode the real message to avoid conflict between the message and the previously defined separators.
And using this approach, I got this implementation:
// Send packets:
socket.write('-${base64Encode("Hi World".codeUnits)}.');
socket.write('-${base64Encode("Hello World".codeUnits)}.');
And to parse the packets:
// Cache the previous parsed packet data.
String parsed = '';
void _handleCompletePacket(String rawPacket) {
// Decode the original message from base64 using [base64Decode].
// And convert the [List<int>] to [String].
final String message = String.fromCharCodes(base64Decode(rawPacket));
print(message);
}
void _handleServerPacket(List<int> rawPacket) {
final String packet = String.fromCharCodes(rawPacket);
final String next = parsed + packet;
final List<String> items = <String>[];
final List<String> tokens = next.split('');
for (int i = 0; i < tokens.length; i++) {
final String char = tokens[i];
if (char == '-') {
if (items.isNotEmpty) {
// malformatted packet.
items.clear();
continue;
}
items.add('');
continue;
} else if (char == '.') {
if (items.isEmpty) {
// malformatted packet.
items.clear();
continue;
}
_handleCompletePacket(items.removeLast());
continue;
} else {
if (items.isEmpty) {
// malformatted packet.
items.clear();
continue;
}
items.last = items.last + char;
continue;
}
}
if (items.isNotEmpty) {
// the last data of this packet was left incomplete.
// cache it to complete with the next packet.
parsed = items.last;
}
}
client.listen(_handleServerPacket);
There are certainly more optimized solutions/approaches, but I got this just for chatting messages within [100-500] characters, so that's fine for now.
I am aiming to make a post request to trigger a IFTTT webhook action. I am using the MKR1010 board. I am able to connect to the network and turn the connected LED on and off using the cloud integration.
The code is as follows, but doesn't trigger the web hook. I can manually paste the web address in a browser and this does trigger the web hook. When the code is posted it returns a 400 bad request error.
The key has been replaced in the below code with a dummy value.
Does anybody know why this is not triggering the web hook? / Can you explain why the post request is being rejected by the server? I don't even really need to read the response from the server as long as it is sent.
Thank you
// ArduinoHttpClient - Version: Latest
#include <ArduinoHttpClient.h>
#include "thingProperties.h"
#define LED_PIN 13
#define BTN1 6
char serverAddress[] = "maker.ifttt.com"; // server address
int port = 443;
WiFiClient wifi;
HttpClient client = HttpClient(wifi, serverAddress, port);
// variables will change:
int btnState = 0; // variable for reading the pushbutton status
int btnPrevState = 0;
void setup() {
// Initialize serial and wait for port to open:
Serial.begin(9600);
// This delay gives the chance to wait for a Serial Monitor without blocking if none is found
delay(1500);
// Defined in thingProperties.h
initProperties();
// Connect to Arduino IoT Cloud
ArduinoCloud.begin(ArduinoIoTPreferredConnection);
/*
The following function allows you to obtain more information
related to the state of network and IoT Cloud connection and errors
the higher number the more granular information you’ll get.
The default is 0 (only errors).
Maximum is 4
*/
setDebugMessageLevel(2);
ArduinoCloud.printDebugInfo();
// setup the board devices
pinMode(LED_PIN, OUTPUT);
pinMode(BTN1, INPUT);
}
void loop() {
ArduinoCloud.update();
// Your code here
// read the state of the pushbutton value:
btnState = digitalRead(BTN1);
if (btnPrevState == 0 && btnState == 1) {
led2 = !led2;
postrequest();
}
digitalWrite(LED_PIN, led2);
btnPrevState = btnState;
}
void onLed1Change() {
// Do something
digitalWrite(LED_PIN, led1);
//Serial.print("The light is ");
if (led1) {
Serial.println("The light is ON");
} else {
// Serial.println("OFF");
}
}
void onLed2Change() {
// Do something
digitalWrite(LED_PIN, led2);
}
void postrequest() {
// String("POST /trigger/btn1press/with/key/mykeyhere")
Serial.println("making POST request");
String contentType = "/trigger/btn1press/with/key";
String postData = "mykeyhere";
client.post("/", contentType, postData);
// read the status code and body of the response
int statusCode = client.responseStatusCode();
String response = client.responseBody();
Serial.print("Status code: ");
Serial.println(statusCode);
Serial.print("Response: ");
Serial.println(response);
Serial.println("Wait five seconds");
delay(5000);
}
Why do you want to make a POST request and send the key in the POST body? The browser sends a GET request. It would be
client.get("/trigger/btn1press/with/key/mykeyhere");
In HttpClient post() the first parameter is 'path', the second parameter is contentType (for example "text/plain") and the third parameter is the body of the HTTP POST request.
So your post should look like
client.post("/trigger/btn1press/with/key/mykeyhere", contentType, postData);
I'm having trouble trying to consume the Response of an HTTP Endpoint which Streams real-time events continously. It's actually one of Docker's endpoints: https://docs.docker.com/engine/api/v1.40/#operation/SystemEvents
I am using Apache HTTP Client 4.5.5 and it just halts indefinitely when I try to consume the content InputStream:
HttpEntity entity = resp.getEntity();
EntityUtils.consume(entity);//it just hangs here.
//Even if I don't call this method, Apache calls it automatically
//after running all my ResponseHandlers
Apparently, it can be done by using JDK's raw URL: Stream a HTTP response in Java
But I cannot do that since local Docker communicates over a Unix Socket which I only managed to configure in Apache's HTTP Client with a 3rd party library for Unix Sockets in Java.
If there is a smarter HTTP Client library which I could switch to, that would also be an option.
Any ideas would be greatly appreciated. Thank you!
I managed to solve this issue by generating an infinite java.util.stream.Stream of JsonObject from the response InputStream (I know the json reading part is not the most elegant solution but there is no better way with that API and also, Docker doesn't send any separator between the jsons).
final InputStream content = response.getEntity().getContent();
final Stream<JsonObject> stream = Stream.generate(
() -> {
JsonObject read = null;
try {
final byte[] tmp = new byte[4096];
while (content.read(tmp) != -1) {
try {
final JsonReader reader = Json.createReader(
new ByteArrayInputStream(tmp)
);
read = reader.readObject();
break;
} catch (final Exception exception) {
//Couldn't parse byte[] to Json,
//try to read more bytes.
}
}
} catch (final IOException ex) {
throw new IllegalStateException(
"IOException when reading streamed JsonObjects!"
);
}
return read;
}
).onClose(
() -> {
try {
((CloseableHttpResponse) response).close();
} catch (final IOException ex) {
//There is a bug in Apache HTTPClient, when closing
//an infinite InputStream: IOException is thrown
//because the client still tries to read the remainder
// of the closed Stream. We should ignore this case.
}
}
);
return stream;
Is there any way to send Upstream notification message through FCM from one android device to another devices connected with Firebase database.
I know that XMPP server can then receive the upstream messages and send the notifications to the other devices.To receive messages sent with the upstream API i need to implement an XMPP server but there is any other way???
Is there any way to send Upstream notification message through FCM
from one android device to another devices connected with Firebase
database?
Currently it's NOT possible to send messages directly from one device to another.
(or at least it's not possible without introducing a HUGE security vulnerability: more details below)
Full details:
Sending messages to a user device is a pretty serious action!
based on the payload a message can result in spam, phishing, execution of internal methods.
You want this operation to be allowed only be trusted entities, this is why the FCM send API requires the SERVER-API-KEY in the authentication header.
Adding the SERVER-API-KEY in your app code (or communicating it to the app in some other way) IS NOT SAFE. This because apk can be extracted, decompiled, inspected, executed on emulators, executed under debugging and so on.
The best way to implement this today: is to have some sort of server between the two devices:
[DeviceA] -- please send message to B --> [SERVER] -- fcmSendAPI --> [DeviceB]
The server can be as simple as a PHP page, or a more complex XMPP implementation.
An example in Node.js can be found here:
Sending notifications between devices with Firebase Database and Cloud Messaging
Finally, after 2 months of trying to maintain reliable server script myself, I suddenly found OneSignal. It's completely free, supports device-to-device push messages on iOS, Android, WP and browsers.
Hope, I won't get flag for promotion spam, but it's currently the only (and easiest) way to be completely "backendless".
Also, it's completely secure way. Nobody can send push unless he knows special OS user id, which you can store in Firebase Database protected by rules.
UPD: It's not a replacement for Firebase. It has only push service and nothing else
UPD2: Firebase now has Functions, and examples of it usage has sending FCM. You now don't need any other server or service. Read more in official samples https://github.com/firebase/functions-samples
After lots of try finally i got one solution and its work perfectly
Step 1 :Include two library.
compile 'com.squareup.okhttp3:okhttp:3.4.1'
compile 'com.google.firebase:firebase-messaging:9.2.0'
Step 2 : In your MainActivity or from where you want to send notifications.
OkHttpClient mClient = new OkHttpClient();
String refreshedToken = "";//add your user refresh tokens who are logged in with firebase.
JSONArray jsonArray = new JSONArray();
jsonArray.put(refreshedToken);
Step 3: Create one async task which sends notifications to all devices.
public void sendMessage(final JSONArray recipients, final String title, final String body, final String icon, final String message) {
new AsyncTask<String, String, String>() {
#Override
protected String doInBackground(String... params) {
try {
JSONObject root = new JSONObject();
JSONObject notification = new JSONObject();
notification.put("body", body);
notification.put("title", title);
notification.put("icon", icon);
JSONObject data = new JSONObject();
data.put("message", message);
root.put("notification", notification);
root.put("data", data);
root.put("registration_ids", recipients);
String result = postToFCM(root.toString());
Log.d("Main Activity", "Result: " + result);
return result;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
try {
JSONObject resultJson = new JSONObject(result);
int success, failure;
success = resultJson.getInt("success");
failure = resultJson.getInt("failure");
Toast.makeText(MainActivity.this, "Message Success: " + success + "Message Failed: " + failure, Toast.LENGTH_LONG).show();
} catch (JSONException e) {
e.printStackTrace();
Toast.makeText(MainActivity.this, "Message Failed, Unknown error occurred.", Toast.LENGTH_LONG).show();
}
}
}.execute();
}
String postToFCM(String bodyString) throws IOException {
public static final String FCM_MESSAGE_URL = "https://fcm.googleapis.com/fcm/send";
final MediaType JSON
= MediaType.parse("application/json; charset=utf-8");
RequestBody body = RequestBody.create(JSON, bodyString);
Request request = new Request.Builder()
.url(Url.FCM_MESSAGE_URL)
.post(body)
.addHeader("Authorization", "key=" + "your server key")
.build();
Response response = mClient.newCall(request).execute();
return response.body().string();
}
Step 4 : Call in onclick of your button
btnSend.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
sendMessage(jsonArray,"Hello","How r u","Http:\\google.com","My Name is Vishal");
}
});
Hi I'm rebuilding a API call using volley library
this is my test code to send XML data and receive xml response (I just need to successfully receive response in string format)
String url ="https://prdesb1.singpost.com/ma/FilterOverseasPostalInfo";
final String payload = "<OverseasPostalInfoDetailsRequest xmlns=\"http://singpost.com/paw/ns\"><Country>AFAFG</Country><Weight>100</Weight><DeliveryServiceName></DeliveryServiceName><ItemType></ItemType><PriceRange>999</PriceRange><DeliveryTimeRange>999</DeliveryTimeRange></OverseasPostalInfoDetailsRequest>\n";
RequestQueue mRequestQueue;
// Instantiate the cache
Cache cache = new DiskBasedCache(getCacheDir(), 1024 * 1024); // 1MB cap
// Set up the network to use HttpURLConnection as the HTTP client.
Network network = new BasicNetwork(new HurlStack());
// Instantiate the RequestQueue with the cache and network.
mRequestQueue = new RequestQueue(cache, network);
// Start the queue
mRequestQueue.start();
// Formulate the request and handle the response.
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
// Do something with the response
Log.v("tesResponse","testResponseS");
Log.v("response",response);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
// Handle error
Log.v("tesResponse","testResponseF");
Log.v("error",error.toString());
}
}
){
#Override
public String getBodyContentType() {
return "application/xml; charset=" +
getParamsEncoding();
}
#Override
public byte[] getBody() throws AuthFailureError {
String postData = payload;
try {
return postData == null ? null :
postData.getBytes(getParamsEncoding());
} catch (UnsupportedEncodingException uee) {
// TODO consider if some other action should be taken
return null;
}
}
};
// stringRequest.setRetryPolicy(new DefaultRetryPolicy(5*DefaultRetryPolicy.DEFAULT_TIMEOUT_MS, 0, 0));
stringRequest.setRetryPolicy(new DefaultRetryPolicy(0, 0, 0));
// Add the request to the RequestQueue.
mRequestQueue.add(stringRequest);
I have test the String url and the payload on POSTMAN and give successful result. But don't know why my android app give this error
08-22 19:44:24.335 16319-16518/com.example.victory1908.test1 D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
[ 08-22 19:44:24.355 16319:16319 D/ ]
HostConnection::get() New Host Connection established 0x7f67de64eac0, tid 16319
[ 08-22 19:44:24.399 16319:16518 D/ ]
HostConnection::get() New Host Connection established 0x7f67de64edc0, tid 16518
08-22 19:44:24.410 16319-16518/com.example.victory1908.test1 I/OpenGLRenderer: Initialized EGL, version 1.4
08-22 19:44:24.662 16319-16319/com.example.victory1908.test1 V/tesResponse: testResponseF
08-22 19:44:24.662 16319-16319/com.example.victory1908.test1 V/error: com.android.volley.NoConnectionError: javax.net.ssl.SSLHandshakeException: Handshake failed
Just notice problem only with API 23+ (android 6.0 and above) API 22 is working fine!
I have tried set the retry policy but does not work. Anyone know what wrong with the code. Thanks in advance