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You are here: Home / Topics / Need Help with interfacing keypad with 8051 using rf module

Need Help with interfacing keypad with 8051 using rf module

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Microcontroller › 8051 › Need Help with interfacing keypad with 8051 using rf module

  • This topic has 3 replies, 3 voices, and was last updated 10 years, 6 months ago by mert.
Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • December 8, 2014 at 6:46 pm #4899
    mert
    Participant

    Hey people,
    I am a newbie here:)
    I have a project with 8051 as I write at the title.Actually my project is very similar to http://www.engineersgarage.com/microcontroller/8051projects/interface-keypad-AT89C51-circuit this one.The differance is I will use a rf module to make it wireless.
    I wrote the codes with assembly and there is no problem with it.I simulated it with both proteus and multisim.But I don’t know how to use preamble and syncron data for rf module coding with assembly.
    Here is the circuit diagram without rf module.I made it to simulate if my codes are right.I will add rf then.

     

     

     

     

    Here is the assembly codes for receiver mcu:

    ORG 0
    MOV DPTR,#TABLO
    BASA:
    MOV P1,#0FFH
    ANL P1,#0FH
    MOV A,P1
    CALL D?SPLAY
    SJMP BASA 
    D?SPLAY:
    MOVC A,@A+DPTR
    MOV P3,A
     
    TABLO:
    DB 3FH
    DB 06H
    DB 5BH
    DB 4FH
    DB 66H
    DB 6DH
    DB 7DH
    DB 07H
    DB 7FH
    DB 6FH
    db 77h
    db 7ch
    db 39h
    db 5eh
    db 79h
    db 71h
    ljmp BASA
    END

    This is the transmitter mcu :

    ORG 00H
    MOV DPTR,#LUT
    MOV P1,#0FFH
    MOV P3,#00H
     
    BACK:MOV P1,#11111111B
         CLR P1.0
    NEXT1:JB P1.4,NEXT2
          MOV A,#1H
          ACALL DISPLAY
    NEXT2:JB P1.5,NEXT3
          MOV A,#2H
          ACALL DISPLAY
    NEXT3:JB P1.6,NEXT4
          MOV A,#3H
          ACALL DISPLAY
    NEXT4:SETB P1.0
          CLR P1.1
          JB P1.4,NEXT5
          MOV A,#4H
          ACALL DISPLAY
    NEXT5:JB P1.5,NEXT6
          MOV A,#5H
          ACALL DISPLAY
    NEXT6:JB P1.6,NEXT7
          MOV A,#6H
          ACALL DISPLAY
    NEXT7:SETB P1.1
          CLR P1.2
          JB P1.4,NEXT8
          MOV A,#7H
          ACALL DISPLAY
    NEXT8:JB P1.5,NEXT9
          MOV A,#8H
          ACALL DISPLAY
    NEXT9:JB P1.6,NEXT10
           MOV A,#9H
           ACALL DISPLAY
    NEXT10:SETB P1.2
           CLR P1.3
           JB P1.5,BACK
           MOV A,#0H
           ACALL DISPLAY
     
           LJMP BACK
     
    DISPLAY:
            MOVC A,@A+DPTR
            MOV P3,A
            RET
     
    LUT: DB 00000000b
         DB 00010000b
         DB 00100000b
         DB 00110000b
         DB 01000000b
         DB 01010000b
         DB 01100000b
         DB 01110000b
         DB 10000000b
         DB 10010000b
         END
    .
     
    And now I need your help.this is my first rf project so I don’t know where and how to add preamble and syncron data.Can you pls help me.For further information you can contact me from [email protected] or here.

     

    December 12, 2014 at 4:18 am #12413
    AJISH ALFRED
    Participant

    Hi mert,

    There are RF modules which transmit data using their own Preample and Sync bits, you dont have to code for it.

    Which RF module are you using?

    December 12, 2014 at 10:58 am #12414
    Ashutosh Bhatt
    Participant

    do u want to transmit keypad codes to another micro controller?

    why u want to do that?

    you need RF encoder-decoder chips like HT12E-HT12D along with RF Tx and Rx modules for this operation

    December 12, 2014 at 7:32 pm #12420
    mert
    Participant

    Hey people,
    Thank you for your replies.
    I will do this for a project of my microchips lecture.And to learn how rf modules work.
    I have a basic 433mhz  rf module already.But i don’t know its model. My rf module doesnt have its preamble codes.So I have to write these codes.
    And yes I have HT12E/D for my circuit.The photo I sent was only for showing what I am trying to do.In addition to this photo i have rf module and HT12 E/D in my circuit.I didnt try it yet because I dont have a 8051 programmer.On monday i will try it at the school.
     

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