help for 89c51

vidya

vidya

@vidya-lQ8fak • Oct 25, 2024
hi all,
im doing a project with 89c51.i have wriiten ALP and it gets loaded into the chip's memory.but,no output is reflected.that is,the chip doesn't react for even asimple 'PORT' command.how do i rectify this.Am i missing out any initializations...if so,wat are the initial setups to be done?
waiting for reply eagerly.pls help.
thanking you
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  • maheshkrishnan

    maheshkrishnan

    @maheshkrishnan-5rk1zA • Mar 28, 2007

    Hi Vidya,
    Did you checked the Xtal connections given correctlly with correct value with ranges from "10 - 13 Mhz"
    Then If you are using 8051 it having internal Rom so no need for using external memory, you should be making the "EA" pin number i hope it is 31 for the 8051 make it to HIGH or (VCC).
    Then I am sure you will get the output with out any problem.
    then comeback with good projects.

    Thanks,
    mahesh krishnan
    0
  • RachaelP

    RachaelP

    @rachaelp-iZbCCq • Mar 28, 2007

    Hi Vidya,

    What port are you looking at when trying to get it to output? If you are trying to output on Port 0 then its a little bit odd in that '0' drives low but write '1' it is floating and/or high-Z input. So basically you need to add external pull-ups on Port 0 pins that are being used as outputs.

    Hope this helps,

    Rach
    0
  • hemant

    hemant

    @hemant-IdOib3 • Mar 30, 2007

    this is good solution i need another one if you able to get
    i m interfacing gsm modem to my microcontroller.i need to send sms
    through it.
    i am using AT commands for that.the command to send sms (AT+ CMGS)
    terminates with
    ctrl-Z.now in my program i hav tried all ways to send ctrl-Z at end of
    my sms.but it takes this as
    a character or string only.also i tried with ascii value of ctrl-Z but
    of no use.

    i am able to see the transmitted commands on hyper-terminal through
    serial interface & also on serail window while debugging.
    the commands are as follows with 2ms delay between each of them.

    AT ,, AT+CMGS = mobile no. , "message to be sent " ctrl-Z it is for the only end of statement
    0