Infrared Emitting data and Receiving unknown data

Hi Trupti,

trupti malekar said:

1.given below code,

unsigned char send_data[8]={0xFF,0xFF,0xFF,0xFF,0x10,0xEF,0xEB,0x14}; Transmitting this data but receiving unknown data.

How are you verifying that you are seeing unknown data? Are you watching the RX_Data buffer in the receiver? Are you using another launchpad with the BOOST-IR booster pack as the receiver or something else? The Receiver example code for the MSP430FR4133 and BOOST-IR Boosterpack expects to receive only 4 bytes typically. 

trupti malekar said:

2. This code required any library or driver?

Looking at this you would require the code in the HAL files included in the project you are using. As well as the register definitions included in msp430.h.

I don't believe there is anything else required here, but if there is missing or undefined symbols here, then there should be errors generated when you compile.  

Best Regards,
Brandon Fisher

I'm using Arduino as the receiver, its possible to receive RX_data?  

Hi Trupti,

I couldn't say what the Arduino you are using is expecting, but it should be possible to receive RX data provided everything is correct.

What kind of receiver are you using on the Arduino side? Are you sure the carrier frequencies are the same?

Best Regards,

Brandon Fisher

Hi Brandon Fisher,

I am using TSOP13238 38kHz AGC2 Receiver.

In below the code, just disable Keypad section.

#include "msp430.h"
#include "HAL_FR4133LP_LCD.h" //Declared and included in Seprate file
#include "HAL_FR4133LP_Board.h" //Declared and included in Seprate file

unsigned char IR_code;
unsigned char IR_flag;
unsigned char IR_stop;
unsigned char byte_cnt;
unsigned int bit_sel;
unsigned char *send_addr;
//unsigned char send_data[4]={0x55, 0xaa, 0x00, 0xff};// Unsigned data will displayed
unsigned char send_data[4]={0x10,0xEF,0xEB,0x14};// Unsigned data will displayed

int main( void )
{
// Watchdog timer works as default setting
WDTCTL = WDTPW + WDTHOLD;

Init_GPIO(); //Initialize GPIO
Init_Clock(); //Initialize Clock
//Init_keypadIO(); //Initialize Keypad
Init_LCD(); //Initialize LCD

LCD_Display_MSP_IR(); // Display "MSP--IR"
LCD_Display_TX(); // Display "TX"

IR_stop = 1; //disable IR emitter

while(1)
{
// clear the flag and counter
IR_flag = 0;
byte_cnt = 0;
bit_sel = 0;

if(IR_stop == 0)
{
// Configure IR output pin
P1SEL0|= BIT0; // use internal IR modulator

// disable Port1 & Port2 interrupt during IR emitting
P1IE = 0;
P2IE = 0;

// IR_code = scan_key(); // scan the keypad

// Configure IR modulation: ASK
SYSCFG1 = IRDSSEL + IREN;
TA1CCTL0 = CCIE;
TA1CCTL2 = OUTMOD_7; // output mode: reset/set
TA0CCTL2 = OUTMOD_7; // output mode: reset/set

// 38kHz 1/4 duty-cycle carrier waveform length setting
TA0CCR0 = 104;
TA0CCR2 = 25;
TA1CCR0 = 640; //the initial time of TA0 should be longer than TA1
TA1CCR2 = 320;

// set timer operation mode
TA0CTL = TASSEL_2 + MC_1 + TACLR; //SMCLK, UP mode
TA1CTL = TASSEL_2 + MC_1 + TACLR; //SMCLK, UP mode

// write button number into buffer
//send_data[2] = IR_code;
//send_data[3] = ~IR_code;
send_addr = &send_data[0];

// stop until the end of IR code
while(IR_stop == 0);

TA0CCTL0 = 0;
TA0CCTL2 = 0;
TA0CTL = 0;
TA0CCR0 = 0;
TA0CCR2 = 0; //disable timer0

TA1CCTL0 = 0;
TA1CCTL2 = 0;
TA1CTL = 0;
TA1CCR0 = 0;
TA1CCR2 = 0; //disable timer1

P1IE |= (BIT3 + BIT4 + BIT5); //enable GPIO interrupt
P2IE |= BIT7;

}
// __bis_SR_register(LPM3_bits | GIE); //enter low power mode
IR_stop = 0; // enable IR code emitting

}
}

//********Timer1 interrupt ISR*********//
#pragma vector = TIMER1_A0_VECTOR
__interrupt void TIMER1_A0_ISR (void)
{
switch( TA1IV )
{
case 0:
{
if(IR_flag)
{
IR_stop=1; // stop IR modulator
TA1CCTL0 &= ~CCIE; // disable timer_A0 interrupt

}

if((byte_cnt==0)&& (bit_sel==0)) // leading pulse burst of IR code
{
TA1CCR0 = 53999; // 9ms high
TA1CCR2 = 35999; // 4.5ms low
byte_cnt++; // byte counter
bit_sel++; // bit counter
}
else if((byte_cnt>= 5)&& (bit_sel==1)) // the end of IR code
{
TA1CCR0 = 2249; //0.562ms pulse burst to show the end
TA1CCR2 = 2249;
IR_flag=1;
}
else
{
if((*send_addr & bit_sel) == 0) // data "0"
{
TA1CCR0 = 4499; // 0.562ms high 0.562ms low
TA1CCR2 = 2249;
bit_sel<<=1;
}
else // data "1"
{
TA1CCR0 = 8999; // 0.562ms high 1.687ms low
TA1CCR2 = 2249;
bit_sel<<=1;
}
if(bit_sel>=256) // start a new byte
{
send_addr++;
byte_cnt++;
bit_sel=1;
}
}
break;
}
default: break;
}
}

I am checking output on port P1.0, output pulse is below image. This is correct?

How to sure the carrier frequencies are the same?

"IR Remote" includes a variety of protocols, mostly not-interoperable. I don't recall which one the BOOST-IR firmware uses.

There are Arduino libraries which can deduce and decode many/most of the common protocols. Here's one that 2-minutes-with-Google turned up:

https://learn.sparkfun.com/tutorials/ir-communication/all

It appears that, even if that library can't figure out what protocol it is, it will give you the received codes so you can detect them in your code.

this is output is correct?

I am checking output on port P1.0, output pulse.

The period for a 38kHz (carrier) signal is about 26usec, so these pulses look about right. What's more interesting is the higher-level pattern of these pulses (zoom out on your scope).

More generally, I think you aren't having trouble with your 38kHz (TSOP) receiver device, since your application is reporting "unknown codes" rather than [nothing at all]. Does your application say anything else about what it received?

10-minutes-with-Google suggests that the BOOST-IR example firmware uses the "NEC IR" protocol (562us pulse separated by either 562us off (0) or 1.7us off (1), though there's more to it):

https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transmission+Protocol

Does your library know this protocol?

[Edit: Minor clarification]