user11396: I have Arduino Uno, Arduino Pro Micro, XY-MK-5V and FS1000A.
I need transmit data from Pro Micro to Uno. 
Transmitter:
    #include <VirtualWire.h>

    void setup() {

      Serial.begin(9600);

      vw_setup(2000);
      vw_set_tx_pin(14);
    }

    void loop() {

      send("Test message!");  
      delay(2000);
    }

    void send (char *message)
    {
      vw_send((uint8_t *)message, strlen(message));
      vw_wait_tx();
    }

Receiver:
#include <VirtualWire.h>

void setup()
{
    Serial.begin(9600);

    vw_set_rx_pin(12);
    vw_setup(2000);

    vw_rx_start();
}

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

    if(vw_get_message(buf, &buflen))
    {
        for(int i = 0; i < buflen; i++)
        {
            Serial.print(buf[i]);
        }

        Serial.println();
    }
}

I dont know why it's doesn't works. When I changed Uno with Micro and Micro with Uno, it's worked.
But I need: Micro + transmitter FS1000A & Uno + receiver XY-MK-5V.
Please help me. I'm using this Pro Micro.

user11396: Thanks for your answers. I solved this problem, my Chinese copy has problems with power.

11396: <p>I have Arduino Uno, Arduino Pro Micro, XY-MK-5V and FS1000A.
I need transmit data from Pro Micro to Uno. </p>

<p>Transmitter:</p>

<pre><code>    #include &lt;VirtualWire.h&gt;

    void setup() {

      Serial.begin(9600);

      vw_setup(2000);
      vw_set_tx_pin(14);
    }

    void loop() {

      send("Test message!");  
      delay(2000);
    }

    void send (char *message)
    {
      vw_send((uint8_t *)message, strlen(message));
      vw_wait_tx();
    }
</code></pre>

<p>Receiver:</p>

<pre><code>#include &lt;VirtualWire.h&gt;

void setup()
{
    Serial.begin(9600);

    vw_set_rx_pin(12);
    vw_setup(2000);

    vw_rx_start();
}

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

    if(vw_get_message(buf, &amp;buflen))
    {
        for(int i = 0; i &lt; buflen; i++)
        {
            Serial.print(buf[i]);
        }

        Serial.println();
    }
}
</code></pre>

<p>I dont know why it's doesn't works. When I changed Uno with Micro and Micro with Uno, it's worked.</p>

<p>But I need: Micro + transmitter FS1000A &amp; Uno + receiver XY-MK-5V.</p>

<p>Please help me. I'm using <a href="https://i.stack.imgur.com/HpDfX.jpg" rel="nofollow noreferrer">this Pro Micro</a>.</p>
 11396: <p>Thanks for your answers. I solved this problem, my Chinese copy has problems with power.</p>
