Published February 26, 2016 © GPL3+

IR LaunchPad to LaunchPad Communication

Send text from one LaunchPad to another using the Grove IR emitter and receiver!

IntermediateFull instructions provided2 hours3,049

Things used in this project

Hardware components

Texas Instruments MSP-EXP430FR6989 MSP430 FRAM LaunchPad

Texas Instruments MSP-EXP430F5529LP MSP430 LaunchPad

Seeed Studio SeeedStudio Grove IR Emitter

Seeed Studio SeeedStudio Grove IR Receiver

Software apps and online services

Texas Instruments Energia

Story

Introduction

This project enables communication from one MSP430F5529 Launchpad to another MSP430FR6989 Launchpad and displays the text received on the built in LCD screen. The transmission of text in this case is just used for an example as it is simply transmitting ASCII values, this project could also be used to transmit sensor data, remote codes, or any other information.

Information Flow Chart

Setup

I developed a custom IR Library in order to get the grove modules to function properly. The library is based on the included IR library in energia as well as the provided arduino library from SeedStudio with the grove module. Because emitting an IR signal takes a PWM pulse of a specific frequency for a specific duration, the library unfortunately had to be hard coded to a pin. In this case, it is tied to pin 40 of the MSP430F5529. The receiver, however, can be put on any pin so long as it has GPIO capabilities. This can be declared when initializing the IRSendRev object.

Finally, as the IR information comes in, it is stored in a char buffer which is then printed to the built in LCD screen using the LCD_Launchpad library which is built into energia.

In the set up in the video, the receiver is tied to pin 5 on the MSP430FR6989 and the emitter tied to pin 40 on the MSP430F5529. The energia serial monitor is used to input text to the MSP430F5529 which then transmits these characters using IR to the MSP430FR6989. The data is stored in the "buffer" char array and then printed to the built in LCD screen!

Demo

Working Demo

Serial Input and Output. Top: Serial output from sending. Bottom: Serial output from receiving.

#include <IRSendRev.h>
#define pb1 PUSH1 
#define BIT_LEN         0
#define BIT_START_H     1
#define BIT_START_L     2
#define BIT_DATA_H      3
#define BIT_DATA_L      4
#define BIT_DATA_LEN    5
#define BIT_DATA        6
 
const int ir_freq = 38;                 // 38k
IRSendRev IR;
unsigned char dtaSend[40];
String buffer;
 
void setup()
{
    IR.setSend(40);
    Serial.begin(115200);
}
 
void loop()
{
  if (Serial.available()){
    buffer = "";
    while(Serial.available()>0){
      buffer += char(Serial.read());
    }
    dtaSend[BIT_DATA_LEN] = buffer.length();
    int i;
    for(i = 0; i<buffer.length();i++){
      dtaSend[BIT_DATA+i] = buffer[i];
    }
    IR.Send(dtaSend, 38);
  }
    delay(100);
}

#include <LCD_Launchpad.h>

#include <IRSendRev.h>
 
#define BIT_LEN         0
#define BIT_START_H     1
#define BIT_START_L     2
#define BIT_DATA_H      3
#define BIT_DATA_L      4
#define BIT_DATA_LEN    5
#define BIT_DATA        6

const int pinRecv = 5;              // ir receiver connect to D2
IRSendRev IR; 
boolean state = 0;
LCD_LAUNCHPAD LCD;
char buffer[40]; 
int dta[40];

void setup()
{
    Serial.begin(115200);
    IR.Init(pinRecv);
    LCD.init();
}

 
void loop()
{
  if(IR.IsDta())                  // get IR data
  {
    IR.Recv(dta);               // receive data to dta
    int i;
    for (i = 0;i<dta[BIT_DATA_LEN];i++){
      buffer[i] =  char(dta[BIT_DATA+i]);
    }
    buffer[i] = '\0';
    LCD.displayScrollText(buffer,400);
  }
}

Credits

Chris Roberts

8 projects • 21 followers

I am an applications engineer with Texas Instruments working with the Launchpad by trade, and a maker by passion!

IR LaunchPad to LaunchPad Communication

Things used in this project

Hardware components

Software apps and online services

Story

Introduction

Setup

Demo

Code

IRSendSerial

IRRecvSerial

IRGrove

Credits

Chris Roberts

Comments

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IR LaunchPad to LaunchPad Communication

IR LaunchPad to LaunchPad Communication

Things used in this project

Hardware components

Software apps and online services

Story

Introduction

Setup

Demo

Code

IRSendSerial

IRRecvSerial

IRGrove

Credits

Chris Roberts

Comments

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