View source for DR RF12

=Introduction=
The DR_RF12 library ([http://svn.dragino.com/examples/libraries/ Download Link])is designed to send/receive data between avr and rfm12b wireless module. It is originated from [http://jeelabs.net/ Jeelabs] [http://jeelabs.net/pub/docs/jeelib/md_intro_rf12.html rf12 driver] with extra software SPI support for Dragino boards. 

DR_RF12 is Arduino IDE compatible. See [http://arduino.cc/en/Guide/Libraries this link] for how to install DR_RF12 in Arduino.

=Examples=
Examples source can be found at [http://svn.dragino.com/examples/libraries/DR_RF12/examples/ this link].

==PingPong test between mrfm12b and nar12==
[[File:rfm12b_pingpong_test.jpg|500px|none|thumb|PingPong test set up for mrfm12b and nar12]]

A PingPong test between mrfm12b and nar12. both nar12 and mrfm12b runs the same arduino sketch, the sketch will continuously send "hello!" to other 434Mhz devices and receive data from others. 

The received data will be sent to the UART interface and display in ms12 or Arduino IDE.

Note: This example also use Ports.h library which can be download from [http://svn.dragino.com/examples/libraries/ here]

====Arduino Code====
<syntaxhighlight lang="c">
#include <DR_RF12.h>
#include <Ports.h>

MilliTimer sendTimer;
char payload[] = "Hello!";
byte needToSend;
int led=13;   // change this to 8 if use mrfm12b

static void sendLed (byte on) {
    digitalWrite(led,on);
}

static void receiveLed (byte on) {
    digitalWrite(led,!on); // inverse, because LED is tied to VCC
}

void setup () {
    delay(8000);  // Wait for 8s until dragino enter autoboot 
    Serial.begin(9600);         // change the baud rate to 115200 if use mrfm12b with ms14
    Serial.println(9600);
    Serial.println("Send and Receive");
    pinMode(led,OUTPUT);
    rf12_initialize(1, RF12_433MHZ, 33);   //initiate rfm12b chip. 
}

void loop () {
    if (rf12_recvDone() && rf12_crc == 0) {    //print received data from rfm12b is any.
        receiveLed(1);
        Serial.print("OK,We Received:   ");
        for (byte i = 0; i < rf12_len; ++i)
            Serial.write(rf12_data[i]);
        Serial.println();
        delay(100); // otherwise led blinking isn't visible
        receiveLed(0);
    }
    
    if (sendTimer.poll(3000))     // set a 3000ms timer , interval of sending data.
        needToSend = 1;

    if (needToSend && rf12_canSend()) {    //Send data via rfm12b
        needToSend = 0;
        
        sendLed(1);
        rf12_sendStart(0, payload, sizeof payload);
        delay(100); // otherwise led blinking isn't visible
        sendLed(0);
    }
}
</syntaxhighlight>

====ms14 Code====
A simple lua script (test.lua) to get data from UART port and show it in SSH. 
<syntaxhighlight lang="lua">
while 1 do
	serialin=io.open("/dev/ttyATH0","r")   --open serial port and prepare to read data from Arduino
	while line==nil do        -- read data from serial. 
         	line=serialin:read() 
         	serialin:flush()
	end
	print(line)    --print the data
	serialin:close()
	line=nil    --clear the line data 
end
</syntaxhighlight>

Run this script in ms14 by:
 root@dragino-01ef80:~# lua test.lua

====Test Result====
[[File:pingPong_result_ms12.jpg|400px|none|thumb|Test Result in ms12]]

[[File:pingPong_result_Arduino.jpg|400px|none|thumb|Test Result in Arduino IDE]]

=Reference=
More examples and documents please refer [http://jeelabs.net/pub/docs/jeelib/md_intro_rf12.html Jeelabs rf12 driver]