vidya
vidya
Branch Unspecified
06 Feb 2007

help for 89c51

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
maheshkrishnan

maheshkrishnan

Branch Unspecified
28 Mar 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
RachaelP

RachaelP

Branch Unspecified
28 Mar 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
hemant

hemant

Branch Unspecified
31 Mar 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

Share this content on your social channels -

Only logged in users can reply.