user45600: Can a cheap RF(transmitter and receiver) module be used for two way communication, not at the same time of course but for example arduino A sends string to be printed on lcd the arduino B receives it and prints it on lcd, then after some time arduino B sends a temperature data back to arduino A, then arduino prints the temperature data on the serial monitor. All of this while arduino A is connected to a transmitter and arduino B is connected a receiver.


user27653: Each device that will ever transmit anything will need a transmitter. Each device that will ever receive anything, needs a receiver. The devices you show in your question are separate receivers and transmitters, so on Arduino A and Arduino B, you will need both a receiver and a transmitter in order to have real, two-way communication between them.
Some RF devices are "Transceivers" which have both a receiver and a transmitter in the same module. Some of these can operate "full-duplex", meaning they can receive at the same time they are transmitting other data (Typically each direction is on a different frequency, but not necessarily.) Most cheap ones are half-duplex, meaning the module can only receive or transmit at any one time.
ADDITIONAL INFORMATION ABOUT RADIOHEAD
Your comment mentioned the RadioHead library. I was able to find the documentation on the library and see that it supports a wide range of radio chipsets and modules. The cheap ones you note are simple ones that use OOK (on-off-keying) or ASK (amplitude-shift-keying) and don't actually have a protocol. The receiver simply provide a HIGH or LOW output if it detects a signal on it's designated receive frequency. The transmitter simply oscillates at the transmit frequency when it's input pin sees a HIGH value, and stops when it sees a LOW value.
The RadioHead RH_ASK class deals with these simple transmitters. The documentation is at http://www.airspayce.com/mikem/arduino/RadioHead/classRH__ASK.html#details
This page notes the way to connect both a transmitter and receiver thus:
Connecting to Arduino

Most transmitters can be connected to Arduino like this:

Arduino                         Transmitter
 GND------------------------------GND
 D12------------------------------Data
 5V-------------------------------VCC

Most receivers can be connected to Arduino like this:

Arduino                         Receiver
 GND------------------------------GND
 D11------------------------------Data
 5V-------------------------------VCC
                                  SHUT (not connected)
                                  WAKEB (not connected)
                                  GND |
                                  ANT |- connect to your antenna syetem


45600: <p>Can a cheap RF(transmitter and receiver) module be used for two way communication, not at the same time of course but for example arduino A sends string to be printed on lcd the arduino B receives it and prints it on lcd, then after some time arduino B sends a temperature data back to arduino A, then arduino prints the temperature data on the serial monitor. All of this while arduino A is connected to a transmitter and arduino B is connected a receiver.
<a href="https://i.stack.imgur.com/yuCpj.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yuCpj.jpg" alt="these are the RF modules i&#39;m using:"></a></p>
 27653: <p>Each device that will ever transmit anything will need a transmitter. Each device that will ever receive anything, needs a receiver. The devices you show in your question are separate receivers and transmitters, so on Arduino A <strong>and</strong> Arduino B, you will need both a receiver and a transmitter in order to have real, two-way communication between them.</p>

<p>Some RF devices are "Transceivers" which have both a receiver and a transmitter in the same module. Some of these can operate "full-duplex", meaning they can receive at the same time they are transmitting other data (Typically each direction is on a different frequency, but not necessarily.) Most cheap ones are half-duplex, meaning the module can only receive or transmit at any one time.</p>

<p><strong>ADDITIONAL INFORMATION ABOUT RADIOHEAD</strong></p>

<p>Your comment mentioned the RadioHead library. I was able to find the documentation on the library and see that it supports a wide range of radio chipsets and modules. The cheap ones you note are simple ones that use OOK (on-off-keying) or ASK (amplitude-shift-keying) and don't actually have a protocol. The receiver simply provide a <code>HIGH</code> or <code>LOW</code> output if it detects a signal on it's designated receive frequency. The transmitter simply oscillates at the transmit frequency when it's input pin sees a <code>HIGH</code> value, and stops when it sees a <code>LOW</code> value.</p>

<p>The RadioHead <code>RH_ASK</code> class deals with these simple transmitters. The documentation is at <a href="http://www.airspayce.com/mikem/arduino/RadioHead/classRH__ASK.html#details" rel="nofollow noreferrer">http://www.airspayce.com/mikem/arduino/RadioHead/classRH__ASK.html#details</a></p>

<p>This page notes the way to connect both a transmitter and receiver thus:</p>

<pre><code>Connecting to Arduino

Most transmitters can be connected to Arduino like this:

Arduino                         Transmitter
 GND------------------------------GND
 D12------------------------------Data
 5V-------------------------------VCC

Most receivers can be connected to Arduino like this:

Arduino                         Receiver
 GND------------------------------GND
 D11------------------------------Data
 5V-------------------------------VCC
                                  SHUT (not connected)
                                  WAKEB (not connected)
                                  GND |
                                  ANT |- connect to your antenna syetem
</code></pre>
