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Decoding IR Control

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AtomSoft

AtomSoft

Well-Known Member
I have a cable TV remote and cant find any information on it online about the IR protocol used. I want to make my own remote soon and would love to learn this protocol.

CHAN 1 BTN: 1101100001000100111101
CHAN 2 BTN: 1101110001000100011101
CH UP BTN: 1101110111000100010001

I hand decoded the bits, or i think i did at least. Can someone help me identify how its used? Like can someone tell me what the parts might be..

I tested a ton of buttons and most if not all start with 1101 ... so i assume thats like a DEVICE ID... If i break it up into parts it looks like

CHN 1 BTN: 1101-1000-0100-0100-1111-01
CHN 2 BTN: 1101-1100-0100-0100-0111-01
CHN UP BTN: 1101-1101-1100-0100-0100-01

But im not sure if thats the case or:


CHAN 1 BTN: 11011-00001-00010-01111-01
CHAN 2 BTN: 11011-10001-00010-00111-01
CH UP BTN: 11011-10111-00010-00100-01

See my issue? I know there is a start pulse also i the front... Anyway here is a Logic saved file... http://www.saleae.com/logic/

The logic software is free so you can inspect my findings... Thanks for the help in advance. Any code created will be shared in this post and my site.
 

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AtomSoft

AtomSoft

Well-Known Member
Ok ive been thinking i checked chan 3 btn also:

1: 11011 0000 1000100 1111 01
2: 11011 1000 1000100 0111 01
3: 11011 0100 1000100 1011 01

Looks like :
first 5 bits are the same (DEVICE?)
next 4 are possibly commands? in LSb form
Next 7 are?
next 4 are inverse of command perhaps...
last 2 are?
 
AtomSoft

AtomSoft

Well-Known Member
Ok further into it now:

Code: 
  01> 11011 0000 1000100 1111 01
  02> 11011 1000 1000100 0111 01
  03> 11011 0100 1000100 1011 01
  04> 11011 1100 1000100 0011 01
  05> 11011 0010 1000100 1101 01
  Up> 11011 1011 1000100 0100 01
Play> 11011 1100 1100100 0011 00
Stop> 11011 0010 1100100 1101 00
First 5 bits must be like some sync i guess
Next 4 bits must be the command
Next 7 bits must be a some sync or something
Next 4 bits must be the inverse of command
Next 2 bits are Device... 01 = TV, 00 = DVR

(im using a Time Warner Cable Box Remote (UR5U-8780L-TWY))

As you can see the command is like SIRC kind of... Button 1 is 0x00, Button 2 is 0x1, Button 3 is 0x2 etc... so there is something similar going on here.... Im tired and will scan more numbers and try to make more sense of this after a break :)
 
Last edited:
AtomSoft

AtomSoft

Well-Known Member
Further study makes me think its like:

Code: 
  01> 11011 0000 10 00100 1111 01
  02> 11011 1000 10 00100 0111 01
  03> 11011 0100 10 00100 1011 01
  04> 11011 1100 10 00100 0011 01
  05> 11011 0010 10 00100 1101 01
  00> 11011 1001 10 00100 0110 01
ChUp> 11011 1011 10 00100 0100 01
ChDn> 11011 0111 10 00100 1000 01
Play> 11011 1100 11 00100 0011 00
Stop> 11011 0010 11 00100 1101 00
Down> 11011 1101 00 00100 0010 11
  Up> 11011 0100 00 00100 1011 11
Left> 11011 1100 00 00100 0011 11
First 5 = SYNC
NEXT 4 = COMMAND
NEXT 2 = DEVICE
NEXT 5 = SYNC INVERTED
NEXT 4 = COMMAND INVERTED
NEXT 2 = DEVICE INVERTED
 
Last edited:
AtomSoft

AtomSoft

Well-Known Member
That would be... 16 Commands per device...with 4 device max... which would mean 64 buttons max for Actual Cable box usage... This is all theory but seems to be making more sense heh

START = 3.3ms LOW then 3.3ms HIGH
A LOGIC 1 = 900us LOW then 2.4ms HIGH
A LOGIC 0 = 900us LOW then 700us HIGH


Ill try to make a decoder with a PIC micro and some fancy UART code to see if i can read it easier :)
 
AtomSoft

AtomSoft

Well-Known Member
Awesome!! Got it i think... This is the results from a test using a PIC18F2525 and CP2102 for USB to UART stuff.. Using CoolTerm(terminal)

Code: 
AtomSoftTech IR Decoder Test
Ready for input...

Sync = 27, Command = 00, Device = 01, Inv. Sync = 04, Inv. Command = 15, Inv.  Device = 02 
Sync = 27, Command = 01, Device = 01, Inv. Sync = 04, Inv. Command = 14, Inv.  Device = 02 
Sync = 27, Command = 02, Device = 01, Inv. Sync = 04, Inv. Command = 13, Inv.  Device = 02 
Sync = 27, Command = 03, Device = 01, Inv. Sync = 04, Inv. Command = 12, Inv.  Device = 02
Buttons 1,2,3 and 4
 
Last edited:
AtomSoft

AtomSoft

Well-Known Member
Here is the code if anyone is interested in it:

Code: 
/*------------------------
Author: Jason Lopez
Company: AtomSoftTech.com
IDE: MPLABX, COMPILER = C18
MCU = PIC18F2525

Info: Time Warner Cable - Remote (UR5U-8780L-TWY) Decoder.
Protocol: Unknown...(somewhat like NEC) SYNC, COMMAND, DEVICE, !SYNC, !COMMAND, !DEVICE
--------------------------*/
#include <p18f2525.h>
#include <delays.h>
#include <string.h>

#pragma config WDT = OFF, LVP = OFF, OSC = INTIO67, XINST = OFF

/************************************
Prototypes
*************************************/
void main(void);
void init_uart(void);
void UartByte(char byte);
void UartStr(rom char *string);
void DecodeTWC(void);

/************************************
 Global Variables and Definitions
*************************************/
#define INPUT 1
#define OUTPUT 0

#define D600US() Delay100TCYx(13)
#define D1MS() Delay100TCYx(20)
#define D1P8MS() Delay100TCYx(36)

#define IR PORTBbits.RB0
#define IR_DDR TRISBbits.TRISB0

#define RSYNC 0x1B
#define NSYNC 0x04

char SyncTmp = 0;
char CmdIn = 0;
char DevIn = 0;
char bytes[6]={0};

void main(void)
{
    char x;
    OSCCON = 0x72;      	//8MHz clock
    while(!OSCCONbits.IOFS);	//wait for osc stable

    ADCON1 = 0x0F;              //All pins digital
    init_uart();                //Init the UART

    IR_DDR = INPUT;             //IR Direction is Input

    UartStr((rom char*)"AtomSoftTech IR Decoder Test\n");
    UartStr((rom char*)"Ready for input...\n\n");
    
    while(1)
    {
        for(x=0;x<6;x++)
            bytes[x] = 0;
        
        DecodeTWC();
        UartStr((rom char*)"Sync = ");
        UartByte(((bytes[0] / 10)+0x30)); UartByte(((bytes[0] % 10)+0x30));
        UartStr((rom char*)", Command = ");
        UartByte(((bytes[1] / 10)+0x30)); UartByte(((bytes[1] % 10)+0x30));
        UartStr((rom char*)", Device = ");
        UartByte(((bytes[2] / 10)+0x30)); UartByte(((bytes[2] % 10)+0x30));

        UartStr((rom char*)", Inv. Sync = ");
        UartByte(((bytes[3] / 10)+0x30)); UartByte(((bytes[3] % 10)+0x30));
        UartStr((rom char*)", Inv. Command = ");
        UartByte(((bytes[4] / 10)+0x30)); UartByte(((bytes[4] % 10)+0x30));
        UartStr((rom char*)", Inv.  Device = ");
        UartByte(((bytes[5] / 10)+0x30)); UartByte(((bytes[5] % 10)+0x30));

        UartStr((rom char*)" \n");
    }
}

void init_uart(void){
    TRISC  = 0b10000000;
    TXSTAbits.SYNC = 0;
    BAUDCTLbits.BRG16 = 0;
    TXSTAbits.BRGH = 1;
    SPBRG = 51;        //9600bps for 8 Mhz

    RCONbits.IPEN = 1;
    IPR1bits.RCIP = 1; //PRIORITY

    TXSTAbits.TXEN = 1;  //ENABLE TX
    RCSTAbits.CREN = 1;  //ENABLE RX
    RCSTAbits.SPEN = 1;  //ENABLE SERIAL PORT and PIN Config

    PIE1bits.RCIE = 0;   //DISABLE RX Interrupt
    PIR1   = 0b00000000;
    PIE1   = 0b00101000;
    IPR1   = 0b00101000;
    INTCON = 0b11000000;

    Delay10TCYx(100);
}
void UartByte(char byte){
    while(!PIR1bits.TXIF)     //wait until TXIF is high
        continue;
    TXREG = byte;    //put byte into Transmit Register
}
void UartStr(rom char *string){
    while(*string)
    {
        while(!PIR1bits.TXIF)     //wait until TXIF is high
            continue;
        TXREG = *string++;    //put byte into Transmit Register
    }
}
void DecodeTWC(void){

    char x;
    char curByte = 0;

    while(IR == 1);     //Waiting For Start...
    while(IR == 0);     //Waiting For Start to go High...
    while(IR == 1);     //Waiting For Start to go Low...

    for(x=0;x<5;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x10;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x0F;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    curByte++;
    for(x=0;x<4;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x08;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x07;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    curByte++;
    for(x=0;x<2;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x02;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x01;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    curByte++;
    for(x=0;x<5;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x10;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x0F;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    curByte++;
    for(x=0;x<4;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x08;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x07;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    curByte++;
    for(x=0;x<2;x++ )
    {
        bytes[curByte] >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            bytes[curByte] |= 0x02;
        D600US();
        if(IR == 0)
        {
            bytes[curByte] &= 0x01;
        }
        else
        {
            D600US();D600US();D600US();
        }
    }
    
    CmdIn = bytes[1];
    DevIn = bytes[2];

    Delay1KTCYx(100);
}
Its kind of like a NEC protocol but with some differences.

Space... Can be made less but heh im tired from the hard work :)
 

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Last edited:
AtomSoft

AtomSoft

Well-Known Member
Smaller Flash usage: (Saved 728 bytes)
Code: 
/*------------------------
Author: Jason Lopez
Company: AtomSoftTech.com
IDE: MPLABX, COMPILER = C18
MCU = PIC18F2525

Info: Time Warner Cable - Remote (UR5U-8780L-TWY) Decoder.
Protocol: Unknown...(somewhat like NEC) SYNC, COMMAND, DEVICE, !SYNC, !COMMAND, !DEVICE
--------------------------*/
#include <p18f2525.h>
#include <delays.h>
#include <string.h>

#pragma config WDT = OFF, LVP = OFF, OSC = INTIO67, XINST = OFF

/************************************
Prototypes
*************************************/
void main(void);
void init_uart(void);
void UartByte(char byte);
void UartStr(rom char *string);
void DecodeTWC(void);
char GetData (char bits);
/************************************
 Global Variables and Definitions
*************************************/
#define INPUT 1
#define OUTPUT 0

#define D600US() Delay100TCYx(13)
#define D1MS() Delay100TCYx(20)
#define D1P8MS() Delay100TCYx(36)

#define IR PORTBbits.RB0
#define IR_DDR TRISBbits.TRISB0

#define RSYNC 0x1B
#define NSYNC 0x04

char SyncTmp = 0;
char CmdIn = 0;
char DevIn = 0;
char bytes[6]={0};

void main(void)
{
    char x;
    OSCCON = 0x72;      	//8MHz clock
    while(!OSCCONbits.IOFS);	//wait for osc stable

    ADCON1 = 0x0F;              //All pins digital
    init_uart();                //Init the UART

    IR_DDR = INPUT;             //IR Direction is Input

    UartStr((rom char*)"AtomSoftTech IR Decoder Test\n");
    UartStr((rom char*)"Ready for input...\n\n");
    
    while(1)
    {
        for(x=0;x<6;x++)
            bytes[x] = 0;
        
        DecodeTWC();
        UartStr((rom char*)"Sync = ");
        UartByte(((bytes[0] / 10)+0x30)); UartByte(((bytes[0] % 10)+0x30));
        UartStr((rom char*)", Command = ");
        UartByte(((bytes[1] / 10)+0x30)); UartByte(((bytes[1] % 10)+0x30));
        UartStr((rom char*)", Device = ");
        UartByte(((bytes[2] / 10)+0x30)); UartByte(((bytes[2] % 10)+0x30));

        UartStr((rom char*)", Inv. Sync = ");
        UartByte(((bytes[3] / 10)+0x30)); UartByte(((bytes[3] % 10)+0x30));
        UartStr((rom char*)", Inv. Command = ");
        UartByte(((bytes[4] / 10)+0x30)); UartByte(((bytes[4] % 10)+0x30));
        UartStr((rom char*)", Inv.  Device = ");
        UartByte(((bytes[5] / 10)+0x30)); UartByte(((bytes[5] % 10)+0x30));

        UartStr((rom char*)" \n");
    }
}

void init_uart(void){
    TRISC  = 0b10000000;
    TXSTAbits.SYNC = 0;
    BAUDCTLbits.BRG16 = 0;
    TXSTAbits.BRGH = 1;
    SPBRG = 51;        //9600bps for 8 Mhz

    RCONbits.IPEN = 1;
    IPR1bits.RCIP = 1; //PRIORITY

    TXSTAbits.TXEN = 1;  //ENABLE TX
    RCSTAbits.CREN = 1;  //ENABLE RX
    RCSTAbits.SPEN = 1;  //ENABLE SERIAL PORT and PIN Config

    PIE1bits.RCIE = 0;   //DISABLE RX Interrupt
    PIR1   = 0b00000000;
    PIE1   = 0b00101000;
    IPR1   = 0b00101000;
    INTCON = 0b11000000;

    Delay10TCYx(100);
}
void UartByte(char byte){
    while(!PIR1bits.TXIF)     //wait until TXIF is high
        continue;
    TXREG = byte;    //put byte into Transmit Register
}
void UartStr(rom char *string){
    while(*string)
    {
        while(!PIR1bits.TXIF)     //wait until TXIF is high
            continue;
        TXREG = *string++;    //put byte into Transmit Register
    }
}
void DecodeTWC(void){

    char x;
    char curByte = 0;

    while(IR == 1);     //Waiting For Start...
    while(IR == 0);     //Waiting For Start to go High...
    while(IR == 1);     //Waiting For Start to go Low...

    bytes[0] = GetData(5);
    bytes[1] = GetData(4);
    bytes[2] = GetData(2);
    bytes[3] = GetData(5);
    bytes[4] = GetData(4);
    bytes[5] = GetData(2);

    Delay1KTCYx(100);
}

char GetData (char bits){
    char x;
    char data=0;

    for(x=0;x<bits;x++ )
    {
        data >>= 1;
        while(IR == 0);
        D600US();
        if(IR == 1)
            data |= (1<<(bits-1));
        D600US();
        if(IR == 0)
        {
            data &= ~(1<<(bits-1));
        }
        else
        {
            D600US();D600US();D600US();
        }
    }

    return data;
}
 

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Last edited:
Mr RB

Mr RB

Well-Known Member
AtomSoft said:
Further study makes me think its like:

Code: 
  01> 11011 0000 10 00100 1111 01
  02> 11011 1000 10 00100 0111 01
  03> 11011 0100 10 00100 1011 01
  04> 11011 1100 10 00100 0011 01
  05> 11011 0010 10 00100 1101 01
  00> 11011 1001 10 00100 0110 01
ChUp> 11011 1011 10 00100 0100 01
ChDn> 11011 0111 10 00100 1000 01
Play> 11011 1100 11 00100 0011 00
Stop> 11011 0010 11 00100 1101 00
Down> 11011 1101 00 00100 0010 11
  Up> 11011 0100 00 00100 1011 11
Left> 11011 1100 00 00100 0011 11
...
Click to expand...
Nicely done Atomsoft! :) I was watching that pattern emerge as you made each post.
 
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