[英]Sending a char array using RF24Network on Arduino
I am trying to use the RF24Network library to create a sensor network in which the root node connects to an MQTT broker using the PubSubCient library. 我正在尝试使用RF24Network库创建传感器网络,其中根节点使用PubSubCient库连接到MQTT代理。
I have done a basic test which relays the MQTT topic and message payload from MQTT to one other node in the network, it does this by using sprintf
to create a delimited string of the current millis()
time on the root node, the topic and message which is stored in a car array of size 200 (as the size of the RF payload must be predefined), I can see from serial output that this is being done correctly. 我已经完成了一项基本测试,该测试将MQTT主题和消息有效负载从MQTT中继到网络中的另一个节点,它通过使用sprintf
在根节点,主题和当前节点上创建当前millis()
时间的定界字符串来完成此任务。消息存储在大小为200的汽车阵列中(因为必须预先定义RF有效负载的大小),我可以从串行输出中看到这已正确完成。
However from the serial output of the receiving node I find that only the first 24 characters of the string are being received and I am out of ideas as to why this is the case. 但是,从接收节点的串行输出中,我发现仅接收到字符串的前24个字符,因此我不知道为什么会这样。
Code for sending node: 发送节点代码:
void ByteToChar(byte* bytes, char* chars, unsigned int count){
for(unsigned int i = 0; i < count; i++)
chars[i] = (char)bytes[i];
chars[count] = '\0';
}
void callback(char* topic, byte* message, unsigned int length) {
Serial.println("Sending...");
char buf[length + 1];
ByteToChar(message, buf, length);
char payload[200];
sprintf(payload, "%lu:%s:%s", millis(), topic, buf);
Serial.println(payload);
Serial.println(sizeof(payload));
RF24NetworkHeader header(other_node);
bool ok = network.write(header, payload, sizeof(payload));
if (ok)
Serial.println("ok.");
else
Serial.println("failed.");
free(payload);
}
And receiving node: 和接收节点:
while ( network.available() )
{
RF24NetworkHeader header;
char payload[200];
memset(payload, 0, 200);
network.read(header, &payload, sizeof(payload));
Serial.println(payload);
Serial.println(sizeof(payload));
free(payload);
}
It's not impossible that I have just overlooked something very simple. 我只是忽略了一些非常简单的事情,这并非没有可能。 Any help is greatly appreciated. 任何帮助是极大的赞赏。
Edit: This would probably be helpful, this is the data I am sending from the root node: 4203:in_3:hello world again
编辑:这可能会有所帮助,这是我从根节点发送的数据: 4203:in_3:hello world again
and this is what I get: 4203:in_3:hello world ag
这就是我得到的: 4203:in_3:hello world ag
Looking into the source of size_t RF24Network::read 查看size_t RF24Network :: read的来源
bufsize = min(maxlen,frame_size-sizeof(RF24NetworkHeader));
That are at most 24 bytes. 最多为24个字节。
I have tried payloads larger than 24 bytes, it works. 我尝试过大于24字节的有效负载,它可以正常工作。 Somehow, the lib supports a FRAGMENTATION feature. lib某种程度上支持FRAGMENTATION功能。 72-byte payload works on UNO, but not bigger. 72字节有效负载可在UNO上使用,但不能更大。
https://tmrh20.github.io/RF24Network/AdvancedConfig.html https://tmrh20.github.io/RF24Network/AdvancedConfig.html
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