Discussion in "8051 Discussion Forum" started by    karthikdm    Oct 27, 2010.
Wed Oct 27 2010, 09:43 AM
#1
Does all four-ports of 89S52 require pull up resistors?
some circuit use pull-ups on all ports...As per data sheet it is needed to use pull-up for port P1 only and others having internal pull-ups..
Wed Oct 27 2010, 10:00 AM
#2
hi karthikdm

Does all four-ports of 89S52 require pull up resistors?


89s52 has 4 ports p0, p1, p2 and p3
all ports has internal pull ups except port 0
port0 needed external pull ups

some circuit use pull-ups on all ports


controller pin's output current is too low some time we need more current then we use external one to by force providing a current even internal pull up exist

As per data sheet it is needed to use pull-up for port P1 only and others having internal pull-ups..


i think u mis understand the pdf
only port 0 need pull ups of 10 k recommended but can be used less
 karthikdm like this.
Wed Oct 27 2010, 10:13 AM
#3
Hi khartik, Majoka is right. Only P0 needs pull ups but sometimes base on my experience even other ports needs pull ups or pull down depends on your design.
Wed Oct 27 2010, 10:27 AM
#4
Thanks clear now...yes majoka its P0 ..not P1
Wed Oct 27 2010, 04:08 PM
#5
hi karthikdm
you r always welcome dear

Get Social

Information

Powered by e107 Forum System

Conversation

Sarvn
Sat Jul 22 2017, 05:12 PM
I wnt to learn embedded could anyone help me
Sarvn
Sat Jul 22 2017, 05:11 PM
Hi
Wed Jul 12 2017, 02:34 PM
Ushiwaka
Any good guides on how to interface an 8255 w/ an 8051?
Tue Jul 11 2017, 06:22 PM
Chiko
i need seconds added to this circuit, can you help me modify it and add codes too
ExperimenterUK
Thu Jul 06 2017, 01:25 AM
@martinsnc115877 The hex file is here http://www.8051projects.net/forum-t65048-post.html
martinsnc115877
Sun Jul 02 2017, 04:28 PM
sir, sorry for the disturbance I can find the small and capital letter,hex file, please send it to me
Sun Jul 02 2017, 11:45 AM
Sam Raj
Can I have the circuit of Simple Digital Voltmeter using 8051
ExperimenterUK
Sun Jul 02 2017, 02:09 AM
Read this http://www.8051projects.net/forum-t65048-post.html. The project download contains lower case letters. It is compiled in Keil
martinsnc115877
Sat Jul 01 2017, 10:45 PM
I mean scrolling massage display using 8051 by pratrik suthar, the hex file I have is just only the capital letters I need the capital letters and the small letters hex, and I will like to no the compiler name he used for the code thanks
ExperimenterUK
Sat Jul 01 2017, 09:13 PM
@martinsnc115877 which project..link ?

Downloads

Comments

Sarvn
Sat Jul 22 2017, 11:34 AM
diablom
Fri Jul 21 2017, 01:44 PM
Alihaider.007
Thu Jul 20 2017, 03:07 PM
Vijaykumarsharma
Fri Jul 14 2017, 11:08 AM
varma495
Tue Jul 11 2017, 01:55 AM
Ramweit
Sat Jul 08 2017, 01:42 PM
Ben_J1
Fri Jul 07 2017, 04:32 PM
labsdg
Fri Jul 07 2017, 02:58 AM

Online

Guests: 50, Members: 0 ...

most ever online: 182184
(Members: , Guests: 182184) on 06 Aug 2010: 05:37 AM

Members: 37860
Newest member: Sarvn
Forum Activity
ExperimenterUK Avatar
Posted By ExperimenterUK
Thu Jul 20 2017, 04:08 PM
can it be possible ?? Alihaider.007No.You will nee...
Alihaider.007 Avatar
Posted By Alihaider.007
Thu Jul 20 2017, 03:14 PM
Sir I am using AT89S8253 I have trying to use this...
Utsavi Avatar
Posted By Utsavi
Mon Jul 17 2017, 09:57 AM
Hello Ajay_Bhargav,Thanks for your reply. Yes, you...
ajay_bhargav Avatar
Posted By ajay_bhargav
Mon Jul 17 2017, 06:41 AM
I do not think it would be a good idea to kind of ...
ajay_bhargav Avatar
Posted By ajay_bhargav
Mon Jul 17 2017, 06:32 AM
Tasking EDE has linker script facility available y...
Ramweit Avatar
Posted By Ramweit
Thu Jul 13 2017, 06:58 AM
Thank you for response,Sim300 gsm Modem am using h...
ExperimenterUK Avatar
Posted By ExperimenterUK
Tue Jul 11 2017, 04:20 PM
After the SMS is sent the modem should respond+CMG...
Ramweit Avatar
Posted By Ramweit
Tue Jul 11 2017, 02:37 PM
From this code gsm modem sending SMS to mobiles mu...
ExperimenterUK Avatar
Posted By ExperimenterUK
Mon Jul 10 2017, 06:09 PM
@RamweitWhat is it you want to know ?
Ramweit Avatar
Posted By Ramweit
Sat Jul 08 2017, 02:12 PM
#include<reg51.h>#include<stdio.h>bit moreov...