I use this code to get a string from server using Web Socket Get on Arduino.
void LedState() {
StaticJsonBuffer<200> jsonBuffer;
String leddata;
if (client.connected()) {
{
}
if (leddata.length() > 0) {
Serial.print("Received leddata: ");
Serial.println(leddata);
if (leddata == "True") {
digitalWrite(LED, HIGH);
Serial.println("led on");
}
if (leddata == "False") {
digitalWrite(LED, LOW);
Serial.println("led off");
}
}
}
if (!client.connected()) {
Serial.println("disconnected");
delay(100);
websocket_connect(); //reconnect with the server
}
}
The problem is that Arduino get the right value for the first time and remain getting this value for a while (some seconds to some minutes) even if the value is changed, and sometime the value doesn't changed on Arduino.
I used a Web Socket test application to test if the problem is with my server or with Arduino and I run it at the same time with Arduino and it get right values while the Arduino stuck on the last value. And sometime if the connection is lost and after reconnect Arduino gets the right value.
You must use client.stop(); after Serial.println("led on"); and after Serial.println("led off");.
Related
on my code i can send an sms to my target number but i don't know how to read or receive sms from target number
the tinyGSM library doesn't have the read member function and i don't know how to use AT commands
void setup() {
// Set console baud rate
SerialMon.begin(115200);
// Keep power when running from battery
Wire.begin(I2C_SDA, I2C_SCL);
bool isOk = setPowerBoostKeepOn(1);
SerialMon.println(String("IP5306 KeepOn ") + (isOk ? "OK" : "FAIL"));
// Set modem reset, enable, power pins
pinMode(MODEM_PWKEY, OUTPUT);
pinMode(MODEM_RST, OUTPUT);
pinMode(MODEM_POWER_ON, OUTPUT);
digitalWrite(MODEM_PWKEY, LOW);
digitalWrite(MODEM_RST, HIGH);
digitalWrite(MODEM_POWER_ON, HIGH);
// Set GSM module baud rate and UART pins
SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
delay(3000);
// Restart SIM800 module, it takes quite some time
// To skip it, call init() instead of restart()
SerialMon.println("Initializing modem...");
modem.restart();
// use modem.init() if you don't need the complete restart
// Unlock your SIM card with a PIN if needed
if (strlen(simPIN) && modem.getSimStatus() != 3 ) {
modem.simUnlock(simPIN);
}
// To send an SMS, call modem.sendSMS(SMS_TARGET, smsMessage)
String smsMessage = "Hello from ESP32!";
/*if(modem.sendSMS(SMS_TARGET, smsMessage))
{
SerialMon.println(smsMessage);
}
else{
SerialMon.println("SMS failed to send");
}*/
SerialAT.println("AT"); //Once the handshake test is successful, it will back to OK
SerialAT.println("AT+CMGF=1"); // Configuring TEXT mode
SerialAT.println("AT+CNMI=1,2,0,0,0"); // Decides how newly arrived SMS messages should be handled
}
void loop()
{
//readSMS(1);
//delay(1);
}
At the moment I try to send packets between one Heltec WIFI LoRa V2 and another by reading the serial-line and sending the input via LoRa.
Small packets (like 30 bytes) work every time, but as bigger the packet gets the packet won't be received every time or even never.
So I write a little sending loop, where my sender sends at every iteration a packet, which gets every time 10 byte bigger, and surprisingly every packet was received by the sender (I tried that until 500 bytes).
After that, I wanted to send a 80 byte serial input message and this did not work. Do you know what's the problem with that?
void setup() {
// ... LoRa.begin(); ....
LoRa.onReceive(onReceive);
// ... LoRa.receive(); ...
}
void onReceive(int packetSize) { // uses the interrupt pin on the dio0
String packet = "";
packSize = String(packetSize,DEC);
for (int i = 0; i < packetSize; i++) {
packet += (char) LoRa.read();
}
Serial.println(packet);
delay(5);
} ```
``` // writer
boolean sendPacket (String packet) {
Serial.println("Send begin");
LoRa.beginPacket(false); // true: optional implicit mode (--> Set everything on both sides?!)
LoRa.setTxPower(14,RF_PACONFIG_PASELECT_PABOOST);
LoRa.print(packet); // also LoRa.write(byte(, length));
LoRa.endPacket(false); // true: async mode: doas not wair until transmission is completed
delay(250);
// put the radio into receive mode
LoRa.receive(); // set redio back in receive mode
delay(750);
Serial.println("Send end");
return true; // will be changed
}
void loop(){
while(Serial.available() > 0 ){
delay(2); //delay to allow byte to arrive in input buffer
String text = Serial.readString();
digitalWrite(LED, HIGH); // turn the LED on (HIGH is the voltage level)
boolean packetSent = false;
while (!packetSent) {
packetSent = sendPacket(text);
if (packetSent) {
Serial.print("Packet has been sent: ");
Serial.println(text);
} else {
Serial.print("Retry sending packet: ");
Serial.println(text);
}
}
digitalWrite(LED, LOW); // turn the LED off (HIGH is the voltage level)
}
} ```
I am working on 3-wheel robot. I want to move my robot front, back, right, left using voice commands. I am using arduino electronics as my mobile app. By using that app I want to control my robot. I am using an arduino uno board and L293D motor driver. Below is my code for 3-wheel robot:
String readvoice;
void setup() {
//BT.begin(9600);
Serial.begin(9600);
pinMode(7, OUTPUT);
digitalWrite(7, HIGH);
}
//-----------------------------------------------------------------------//
void loop() {
while (Serial.available()) { //Check if there is an available byte to read
delay(10); //Delay added to make thing stable
char c = Serial.read(); //Conduct a serial read
readvoice += c; //build the string- "forward", "reverse", "left" and "right"
}
if (readvoice.length() > 0) {
Serial.println(readvoice);
if (readvoice == "go")
{
//Serial.println("front"); //Writing values to motor driver
digitalWrite(4,HIGH);
digitalWrite(5,LOW);
digitalWrite(7,LOW);
digitalWrite(6,HIGH);
}
if (readvoice == "left")
{
//Serial.println("left");
digitalWrite(4,HIGH);
digitalWrite(5,LOW);
digitalWrite(7,HIGH);
digitalWrite(6,LOW);
}
if(readvoice == "right")
{
//Serial.println("right");
digitalWrite(4,LOW);
digitalWrite(5,HIGH);
digitalWrite(7,LOW);
digitalWrite(6,HIGH);
}
if (readvoice == "back")
{
//Serial.println("back");
digitalWrite(4,LOW);
digitalWrite(5,HIGH);
digitalWrite(7,HIGH);
digitalWrite(6,LOW);
}
if (readvoice == "stop")
{
//Serial.println("stop");
digitalWrite(4,LOW);
digitalWrite(5,LOW);
digitalWrite(7,LOW);
digitalWrite(6,LOW);
}
readvoice = "";
}
}
I kept all the connections correctly, but my robot is able to move only right and front. I am not able to run my robot either left or back. Is there any problem in the code? Or any problem with hardware. If i had any problem with hardware, my robot should not move front or right either, but it is moving. Any idea what is wrong with back and left?
I am using Arduino GSM Shield receiving SMS from an Android app. And the content of this SMS will control a LED. If the content of this SMS is not "off", the LED will be on and the content will be printed in the serial monitor. But if it is "off", the LED will be off immediately. Besides, the LED will keep being on until the "off" message coming. For now, I used the code from the example of the software. But I cannot use the content of this SMS to control the status of LED. With the code below, the LED could not be turned on and the content could not be displayed on the monitor. I think it was because the sketch failed to get the whole content of this SMS. Could anybody tell me how to solve this problem? Thanks.
#include <GSM.h>
GSM gsmAccess;
GSM_SMS sms;
char senderNumber[20];
int led=13;
void setup()
{
Serial.begin(9600);
pinMode(led,OUTPUT);
digitalWrite(led,LOW);
while (!Serial) {
;
}
Serial.println("SMS Messages Receiver");
boolean notConnected = true;
while(notConnected)
{
if(gsmAccess.begin("6442")==GSM_READY)
notConnected = false;
else
{
Serial.println("Not connected");
delay(1000);
}
}
Serial.println("GSM initialized");
Serial.println("Waiting for messages");
}
void loop()
{
char c;
int val=0;
val=digitalRead(led);
if (val==HIGH){
digitalWrite(led,HIGH);
}
if (sms.available())
{
Serial.println("Message received from:");
sms.remoteNumber(senderNumber, 20);
Serial.println(senderNumber);
if(sms.peek()=='#')
{
Serial.println("Discarded SMS");
sms.flush();
}
while(c=sms.read())
if(c='off'){
digitalWrite(led,LOW);
}else{
digitalWrite(led,HIGH);
Serial.print(c);
}
Serial.println("\nEND OF MESSAGE");
sms.flush();
Serial.println("MESSAGE DELETED");
}
delay(1000);
}
With this line
if(c='off'){
you are setting the value of c to "off". I guess you want to compare the value of c to the string "off" instead. Use == instead of =.
Also, what happens if someone sends "OFF" instead of "off"......? you need to handle that case as well. Try converting the SMS to lower characters before you do the compare.
I am writing a kind of chat server app where a message received from one websocket client is sent out to all other websocket clients. To do this, I keep the connected clients in a list. When a client disconnects, I need to remove it from the list (so that future "sends" do not fail).
However, sometimes when a client disconnects, the server just gets an exception "connection reset by peer", and the code does not get chance to remove from the client list. Is there a way to guarantee a "nice" notification that the connection has been reset?
My code is:
void WsRequestHandler::handleRequest(HTTPServerRequest &req, HTTPServerResponse &resp)
{
int n;
Poco::Timespan timeOut(5,0);
try
{
req.set("Connection","Upgrade"); // knock out any extra tokens firefox may send such as "keep-alive"
ws = new WebSocket(req, resp);
ws->setKeepAlive(false);
connectedSockets->push_back(this);
do
{
flags = 0;
if (!ws->poll(timeOut,Poco::Net::Socket::SELECT_READ || Poco::Net::Socket::SELECT_ERROR))
{
// cout << ".";
}
else
{
n = ws->receiveFrame(buffer, sizeof(buffer), flags);
if (n > 0)
{
if ((flags & WebSocket::FRAME_OP_BITMASK) == WebSocket::FRAME_OP_BINARY)
{
// process and send out to all other clients
DoReceived(ws, buffer, n);
}
}
}
}
while ((flags & WebSocket::FRAME_OP_BITMASK) != WebSocket::FRAME_OP_CLOSE);
// client has closed, so remove from list
for (vector<WsRequestHandler *>::iterator it = connectedSockets->begin() ; it != connectedSockets->end(); ++it)
{
if (*it == this)
{
connectedSockets->erase(it);
logger->information("Connection closed %s", ws->peerAddress().toString());
break;
}
}
delete(ws);
ws = NULL;
}
catch (WebSocketException& exc)
{
//never gets called
}
}
See receiveFrame() documentation:
Returns the number of bytes received. A return value of 0 means that the peer has shut down or closed the connection.
So if receiveFrame() call returns zero, you can act acordingly.
I do not know if this is an answer to the question, but the implementation you have done does not deal with PING frames. This is currently (as of my POCO version: 1.7.5) not done automatically by the POCO framework. I put up a question about that recently. According to the RFC (6465), the ping and pong frames are used (among others) as a keep-alive function. This may therefore be critical to get right in order to get your connection stable over time. Much of this is guess-work from my side as I am experimenting with this now myself.
#Alex, you are a main developer of POCO I believe, a comment on my answer would be much appreciated.
I extended the catch, to do some exception handling for "Connection reset by peer".
catch (Poco::Net::WebSocketException& exc)
{
// Do something
}
catch (Poco::Exception& e)
{
// This is where the "Connection reset by peer" lands
}
A bit late to the party here... but I am using Poco and Websockets as well - and properly handling disconnects was tricky.
I ended up implementing a simple ping functionality myself where the client side sends an ACK message for every WS Frame it receives. A separate thread on the server side tries to read the ACK messages - and it will now detect when the client has disconnected by looking at flags | WebSocket::FRAME_OP_CLOSE.
//Serverside - POCO. Start thread for receiving ACK packages. Needed in order to detect when websocket is closed!
thread t0([&]()->void{
while((!KillFlag && ws!= nullptr && flags & WebSocket::FRAME_OP_BITMASK) != WebSocket::FRAME_OP_CLOSE && machineConnection != nullptr){
try{
if(ws == nullptr){
return;
}
if(ws->available() > 0){
int len = ws->receiveFrame(buffer, sizeof(buffer), flags);
}
else{
Util::Sleep(10);
}
}
catch(Poco::Exception &pex){
flags = flags | WebSocket::FRAME_OP_CLOSE;
return;
}
catch(...){
//log::info(string("Unknown exception in ACK Thread drained"));
return;
}
}
log::debug("OperatorWebHandler::HttpRequestHandler() Websocket Acking thread DONE");
});
on the client side I just send a dummy "ACK" message back to the server (JS) every time I receive a WS frame from the server (POCO).
websocket.onmessage = (evt) => {
_this.receivedData = JSON.parse(evt.data);
websocket.send("ACK");
};
It is not about disconnect handling, rather about the stability of the connection.
Had some issues with POCO Websocket server in StreamSocket mode and C# client. Sometimes the client sends Pong messages with zero length payload and disconnect occurs so I added Ping and Pong handling code.
int WebSocketImpl::receiveBytes(void* buffer, int length, int)
{
char mask[4];
bool useMask;
_frameFlags = 0;
for (;;) {
int payloadLength = receiveHeader(mask, useMask);
int frameOp = _frameFlags & WebSocket::FRAME_OP_BITMASK;
if (frameOp == WebSocket::FRAME_OP_PONG || frameOp ==
WebSocket::FRAME_OP_PING) {
std::vector<char> tmp(payloadLength);
if (payloadLength != 0) {
receivePayload(tmp.data(), payloadLength, mask, useMask);
}
if (frameOp == WebSocket::FRAME_OP_PING) {
sendBytes(tmp.data(), payloadLength, WebSocket::FRAME_OP_PONG);
}
continue;
}
if (payloadLength <= 0)
return payloadLength;
if (payloadLength > length)
throw WebSocketException(Poco::format("Insufficient buffer for
payload size %d", payloadLength),
WebSocket::WS_ERR_PAYLOAD_TOO_BIG);
return receivePayload(reinterpret_cast<char*>(buffer), payloadLength,
mask, useMask);
}
}