Electronic Circuits Projects Diagrams Free - 8051/8951

Ds80c400/410

priestnot — Tue, 17 Nov 2009 20:14:28 GMT

First of all thanks for the time you will expend trying to help me...

Now have some questions about the DS80C400/410 network micro-controller.

The first one, i want to use TINIOS and slush in the DS80C410? So I can program it in java.

I checked the schematics and i see that i need some old memories (and they recommend them). Did any one tried to do this do you have schematics?

For TCP/IP (Ethernet) communication with the micro-controller (DS80C410) is it necessary any special circuits or i can connect it directly to a rj45 cable? (Witch ports/pins i must use?).
Is there any example/schematic how to do it?

Once more i thank you for your time...

Temperature comparator circuit

Fantascy — Fri, 13 Nov 2009 23:39:17 GMT

i want to feed the output of a temperature comparator circuit to a digital circuit. the temperature sensing consists of lm35 as the sensor, op amp for comparing blw a ref voltage and input voltage. will lm311 as op amp be better than the conventional op amp and how should I modify circuit to avoid switching front and back near the difference point because it will appear almost as analog signal to the digital circuit. Circuit diagrams needed please.

can some 1 get me the code for this please ..really need it

ozikid — Wed, 11 Nov 2009 03:49:15 GMT

This program is designed to help you understand keypad programming using T89C51AC2
; Your task is to write a subroutine for the public section of the keypad library and insert the 16 scan codes.
;
; Part A Use your keypad to work out the 16 scan codes and insert them in the SCode ROM table below in binary.
;
; Part B Write the decode routine that converts a keypad scan code into its table offset value. This is done
; by searching for the matching scan code in the SCode array. The routine returns this index in ACC
;
; Test you program in the LCD-KeyPad simulator for a number of different scan code values
;/*----------------------------------------------------------------------------------------------------------

dseg At 21h
stack: ds 1 ; reserve stack space

cseg
;/*--------------------------------------------------------------------------------------
Main:
mov sp,#stack ; Set up stack area
M1:
acall process ; display any key pressed - ACC holds the result
sjmp M1 ; do it all again
ret

;/*--------------------------------------------------------------------------------------
process:

mov a,#10111101b ; TEST value - *** change this for testing ***
acall decode ; Decode key
ret

;################################################# #######################################
; Key Pad Subroutine Library for EMU750
;################################################# #######################################
;LCD Constants
;~~~~~~~~~~~
ALL_ON equ 0F0h ; turns on all rows, also iused to compare
ROW0 equ 0FEh ; used to initialize first row
ROW4 equ 0EFh ; used to check for last row
CODE_CNT equ 16 ; number of scan codes

KP_PORT equ P0 ;port 0 8 bits

;************************************************* ****************************************
; Public Subroutines - called from main section of code
;************************************************* ****************************************

; *** leave this area empty

;************************************************* ****************************************
; Private Subroutines - Not used in an application
;************************************************* ****************************************

;/*--------------------------------------------------------------------------------------
;TASK: Converts a keypad scan code into an array index value between 0 and 15
;@param: ACC - has the scan code to be converted
;@return: ACC - holds the array index related to the scan code
;/*--------------------------------------------------------------------------------------
Decode:

; Your code here - You must preserve all registers used except ACC

ret

; *** SAMPLE Scan Codes ONLY - Change these k-pad scan codes to the correct ones

SCode: db 11101011b, 01110111b, 01111011b, 01111101b
db 10110111b, 10111011b, 10111101b, 11010111b
db 11011011b, 11011101b, 01111110b, 10111110b
db 11011110b, 11101110b, 11100111b, 11101101b
; db 11111111b

;################################################# ########################################

end

At89c2051 programmer

sunilthorat — Tue, 10 Nov 2009 06:07:12 GMT

please tell me a suitable programmer circuit for at89c2051 microcontroller.
i have used rs232 programmer, but it is not successful.
actually i have used 'proload' software for that but it doesn't detect the device.
i have attached its ckt diagram. Can i use this for at89c2051 �c or any other?
please help me....

Attached Thumbnails

Factorial of a no

ElectronicsDevil — Fri, 06 Nov 2009 17:53:21 GMT

I m having trouble with keil for 89c51. I want to find out factorial of a no. On keil. No are from 0-9. When the answer is greater than 255 we need to split the term in 2 memory locations but i dont know how it can be done.can anyone help me plz....

Need help with a program for 8051

senio — Thu, 05 Nov 2009 15:04:38 GMT

Im stuk to make a program for digits display :(
The program must receive some numbers and send that to a matrix digits, controled by multiplex.If you are more advanced and think that you can help me please view some project schematics (sorry datashet are hand writen) you will find my YM address in documents.Thanks!

Download schematic and system description

help!!! writing a temperture sensor project

mikeneo90 — Thu, 05 Nov 2009 06:38:06 GMT

hi i am doing my final year project and i need help in writing a temperature sensor project using 8051 chip and 8040 ADC i have to write a programme using c language need help form you guys as i don know how to write it out thankssss!!!!!!!!

Need help understanding some code for the 8051(Syntax related)

reenalalu — Mon, 02 Nov 2009 08:16:28 GMT

Take a look at the two snippets of code below. It was written for an 8051 micro-controller.

void main (void)
{
unsigned int a,i;
a=11;
for(i=0;i=8;i++)
{
If ((a>i)&0x1==1)
{
delay();
}

}
}

My question with regards to the above section of code are:
1.What does the IF condition in this code do? I don�t understand it. According to the person who wrote this code, the condition compares to see if each bit of a = 1/0. If it is a 1, then the delay function is called. How does this comparison work??????
2.Can this exact same if condition be used as it is on the PIC uController without any syntax change?

Here is the second piece of code again written for a 8051 uController

void main (void)
{
unsigned int a=0,i;
for(i=0;i=4;i++)
{
if (P1_1=0) //if a port is low
{
a=a|1< }
}

}

1.What does a=a|1< do? And how does it function?
2.Lets say when i=0,1,2,3,4 , P1_1=0. What would the value of a be in this case?
3.If P1_1=0 when i=0,1,2 and 4 but at i=3 this condition is false. What is the value of a in this case?
4.Can this line of code be used just as it is for the PIC uController (i mean with regards to syntax)?

Really looking forward to hearing from everyone

reenalalu

Diagram of a 8051 Digital IO pin.

alphacat — Fri, 30 Oct 2009 21:55:54 GMT

Hello.

I have a 8051 Uc and I can configure the Digital I/O pins to be one of the several options below:
1. Input with an internal pull-up.
2. Input with an internal pull-down.
3. tri-state.
4. 1L output.
5. 0L output.

How does a diagram of such pin looks like?

Thank you.

Code needed for encryption/decrption on same algorithm

nitroracerz — Thu, 29 Oct 2009 08:26:26 GMT

Hi guyz....
i am working on project that is secured data wireless communication.I am using AT89S52 as transmitter and AT89C2051 at receiver end.
This project is used to communicate or transmit a text message from one place to another place through wireless. The text message is encrypted by using the Microcontroller and the encrypted message was transmitted through wireless. At the receiver end the signal was received by the standard receiver and the analog signal was fed to the Microcontroller and it was decrypted by the Microcontroller and the message was displayed over the LCD display. We can use several receivers and the message from the transmitter can be sent to the entire receivers at the same time. Each receiver can be accessed separately by its address.The Microcontroller is used to do the above work. It gets data from the Keyboard and encrypt with an private algorithm and at the receiver end the Microcontroller decrypt it with the same algorithm and display the data over the LCD display.

please guide me through
i needed the code in c programming.............
kindly help me....
Waiting for response
Regards

How do I program the microcontroller?

robortwillys — Thu, 29 Oct 2009 07:41:49 GMT

Hi to all,

I'm the student of the Electronics and I want to learn to program the microcontroller. How can I learn to program 8051 microcontroller?

ASM to C conversion

nitroracerz — Wed, 28 Oct 2009 16:38:19 GMT

Hi guyz....
i m working on project secured wireless data communication which is based on at89s52 using in transmitter circuit as for encryption the text message....and at reciever end at89s2051 is used for decryption the data...i want to convert my asm files in c language please guys help me i had short time...i had to submit this project in time...help me guyz thanks in advance
my email is nitroracerz@hotmail.com

AT89S51----can anyone suggest a replacement

reenalalu — Wed, 28 Oct 2009 14:07:54 GMT

Hi. I have been working on a project based on the AT89S51 micro-controller. I want to simulate this project on Proteus but the problem is that Proteus does not have the AT89S51 as a component. Can anyone please suggest the name of another Microcontroller that i can replace it with, without having to change any of the code. What about the AT89C51???? Can it be used in place of the 89s51. :(

How To Understand �-controller

usmanfaisal — Tue, 27 Oct 2009 20:46:00 GMT

hi
i want to understand the number of microcontrollers.
for example "89c51"
what does 'c' stands for?
what is '89'?
what is '51'?
can anyone tell me details about it?
i'll be grateful.
regards
USMAN

Produce 2 square wave at the same time

nanoha — Mon, 26 Oct 2009 09:31:59 GMT

Hello,
I had a 8051 micro C test last week and it ask us to produce 2 square wave of different freq at the same time. (make it appear at oscilloscope)

I stuck when I need to create both of the wave simultaneously. Actually, I don't even know that we can do something simultaneously using micro C.

Even if I use interrupt (for the second wave), isn't the controller leave the main program and read the interrupt program? So I don't see that I can produce both of them simultaneously.

Any idea??? (Or maybe there is something wrong with my understanding. Hope you guys can help.)