RN 42 Bluetooth

Table of Contents

  1. Hello World!
  2. Connectivity
  3. Tech Specs
  4. RN42 Breakout board

This module provides a very simple way to replace a serial cable connection with a Bluetooth Serial Port Profile (SPP) connection.

As well has having a good set of features accessible via an AT-style command set, one great feature is that out of the box, it is configured to be a serial port host listening for an incoming serial port request. This means that immediately, without any configuration, you can pair the RN42 with a Bluetooth enabled computer, and have a 115200-8-N-1 serial connection

/media/uploads/simon/_scaled_rn42bluetooth.jpg /media/uploads/chris/rn42.png

Hello World!

Import program
RN42-HelloWorld - main.cpp

00001 #include "mbed.h"
00002 
00003 Serial rn42(p9,p10);
00004 DigitalOut myled(LED1);
00005 
00006 int main() {
00007 
00008     rn42.baud(115200);
00009 
00010     // echo back characters, toggle the LED
00011     while (1) {
00012         if (rn42.readable()) {
00013             rn42.putc(rn42.getc());
00014             myled = !myled;
00015         }
00016     }
00017 }

Connectivity

RN42 Pinmbed Pin
1 - GNDGND
11 - VDDVout
12 - GNDGND
13 - RXp9
14 - TXp10
28 - GNDGND
29 - GNDGND

Tech Specs

  • Single 3.3v supply
  • Good power consumption figure (typical)
  • 26uA in standby
  • 25mA - Idle Connection
  • 40mA - Active connection
  • Simple interface for serial cable replacement
  • Power, Ground, Tx, Rx
  • Defaults :
  • SPP, 115,200-8-N-1
  • Bluetooth passkey "1234"

RN42 Breakout board

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