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arduino - PubNub Arduino 订阅

转载 作者:行者123 更新时间:2023-12-02 16:14:33 27 4
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您好,我正在使用 https://github.com/pubnub/arduino 中的 PubNubsubscriber 示例我能够接收消息,只要我收到消息,一切都运行正常,如果一段时间过去了,比如20秒没有新消息,arduino似乎卡住在“等待消息(订阅)”并且无法接收新传入消息

谁知道为什么会发生这种情况?

  /*
PubNub sample subscribe client

This sample client will subscribe to and handle raw PubNub messages
(not doing any JSON decoding). It does so with a randomly generated
UUID.

Circuit:
* Ethernet shield attached to pins 10, 11, 12, 13
* (Optional.) LED on pin 8 for reception indication.
* Pin A4 unconnected (noise source for random number generator)

created 23 October 2012
by Petr Baudis

https://github.com/pubnub/pubnub-api/tree/master/arduino
This code is in the public domain.
*/

#include <SPI.h>
#include <Ethernet.h>
#include <PubNub.h>

// Some Ethernet shields have a MAC address printed on a sticker on the shield;
// fill in that address here, or choose your own at random:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

const int subLedPin = 8;

char pubkey[] =
char subkey[] =
char channel[] = "hello_world";
char uuid[] = "xxxxxxxx-xxxx-4444-9999-xxxxxxxxxxxx";

void random_uuid() {
randomSeed(analogRead(4) + millis() * 1024);
snprintf(uuid, sizeof(uuid), "%04lx%04lx-%04lx-4444-9999-%04lx%04lx%04lx",
random(0x10000), random(0x10000), random(0x10000),
random(0x10000), random(0x10000), random(0x10000));
}

void setup()
{
pinMode(subLedPin, OUTPUT);
digitalWrite(subLedPin, LOW);

Serial.begin(9600);
Serial.println("Serial set up");

while (!Ethernet.begin(mac)) {
Serial.println("Ethernet setup error");
delay(1000);
}
Serial.println("Ethernet set up");

PubNub.begin(pubkey, subkey);
random_uuid();
PubNub.set_uuid(uuid);
Serial.println("PubNub set up");
}

void flash(int ledPin)
{
/* Flash LED three times. */
for (int i = 0; i < 3; i++) {
digitalWrite(ledPin, HIGH);
delay(100);
digitalWrite(ledPin, LOW);
delay(100);
}
}

void loop()
{
Ethernet.maintain();

PubSubClient *client;

Serial.println("waiting for a message (subscribe)");
client = PubNub.subscribe(channel);
if (!client) {
Serial.println("subscription error");
delay(1000);
return;
}
Serial.print("Received: ");
while (client->wait_for_data()) {
char c = client->read();
Serial.print(c);
}
client->stop();
Serial.println();
flash(subLedPin);

delay(200);
}

最佳答案

我花了一些时间,在尝试获取时间 token 时发现问题出在 void PubSubClient::stop() 函数中。现在我不太确定这里到底发生了什么以及为什么它被卡住,尽管看起来如果你终止这里的连接并跳过 timetoken 捕获,它就像一个魅力。

这是PubNub.cpp中的原始代码:

void PubSubClient::stop()
{
if ((!available() && !connected()) || !json_enabled) {
PubNub_BASE_CLIENT::stop();
return;
}
/* We are still connected. Read the rest of the stream so that
* we catch the timetoken. */
while (wait_for_data()) {
char ch = read();
this->_state_input(ch, NULL, 0);
}
json_enabled = false;
}

我(暂时)替换为:

void PubSubClient::stop()
{
PubNub_BASE_CLIENT::stop();
return;
}

目前这是一个解决方法(没有时间 token ),我希望这会有所帮助,直到找到正确的解决方案。

关于arduino - PubNub Arduino 订阅,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/25432132/

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