使用433 MHz发送器/接收器将消息从一个arduino发送到另一个

Question

Today I got some cool radio receiver and transmitter the problem is that when I type the message I want to send it spits out gibbirish on the other arduino.

//transmitter
#include <VirtualWire.h>

void setup()
{
  Serial.begin(9600);
  vw_set_ptt_inverted(true);
  vw_setup(3000);
  vw_set_tx_pin(7);
}

void loop()
{
  String inData;

  while(Serial.available())
  {
    char recieved = Serial.read();
    inData += recieved; 
    char bits[inData.length()];

    Serial.print(":");
    Serial.print(inData);


    for(int i=0;i<inData.length();i++)
    {
    bits[i] = inData.charAt(i);

    vw_send((uint8_t *)bits[i], 1);
    }

    inData = "";
    delay(50);
  }
}

//below is the receiver!

#include <VirtualWire.h>

void setup()
{
  vw_set_ptt_inverted(true);
  pinMode(13,OUTPUT);
  digitalWrite(13,LOW);
  Serial.begin(9600);
  vw_setup(3000);
  vw_set_rx_pin(7);
  vw_rx_start();
}

void loop()
{
  uint8_t buflen = VW_MAX_MESSAGE_LEN;
  uint8_t buf[buflen];

  if(vw_get_message(buf, &buflen))
  {
    for(int i = 0;i < buflen;i++)
    {
     char c = buf[i];
     Serial.println(c,DEC);

      delay(50);
    }
  }
}

So if i type in "hello", on the other serial port I will see "0 53 0 0 2" which is weird due to the fact that I always get the same amount of characters but not the actual character I want.

Answer 1

So I do not have an answer per se, as I do not know that it will help, but I noticed some quirks in your code.

I noticed that you configure the pin for OUTPUT in the receiver, yet you want it to act as a receiver. I am not familiar enough with Arduino hardware and its configurations, but be sure that setting it to OUTPUT will not affect its ability to be driven by a transmitter. What could likely be happening is that there is contention on the line - your transmitter is sending out the data, but the receiver is trying to hold the line LOW , leading to garbage data (with the same number of characters you transmitted!).

Also, based on the samples posted here , it seems that you need to define the transmit enable pin in both cases. It looks like the library has an interrupt service routine that relies on that PTT line to indicate a start of transmission. That can cause a lot of problems for either end which may be relying on a PTT interrupt to send out or receive a signal, especially if flow control is involved.

Lastly, the example code makes use of a vw_wait_tx() function call before sending out more data. You are only waiting 50ms before trying to do another TX operation, which may not be enough time for the transmitter to finish sending out whatever data it has. I do not know the specific implementation of the library, but I would definitely use this function to be sure that you are not trying to send out more data than the port can handle.