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The question is attached as a pdf
1181049573_1340_FT0_micprojects.pdf]]> Tue, 05 Jun 2007 06:19:34 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html one by one.
For now.. i think start from Timer and Calculator
I will you at each step where you feel stuck ok and after you complete it successfully. I will put it in my site.
In project A... first make the "As Timer" functionality.

» Now here is something you must do. make a routine which produce 1 sec delay.
Hint: see machine cycles of instruction you are using for perfect time delay and use 12MHz crystal. don't forget to include the machine cycle for Lcall instruction.

After you are done making that routine. make a small hardware which blinks an LED at a port with the delay routine u created. so you can check whether or not your routine is creating 1 sec delay or not.

I hope you will finish with this by tomorrow. I will guide you to the next step after this.]]> contact@nospam.com (Ajay Bhargav) Tue, 05 Jun 2007 07:54:44 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html i used a 74LS138, and i attached port 7 to a 74373 latch which s attached to the led , the program is


ledout:mov al,1
mov DX,373
out dx,al
JMP delay
delay:mov cx, 0fh
mov dx, 4240h
mov ah, 86h
int 15h
loop ledout
]]> contact@nospam.com (Ajay Bhargav) Tue, 05 Jun 2007 08:30:46 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html think of something what you can do next.. then i will guide you ]]> contact@nospam.com (Ajay Bhargav) Tue, 05 Jun 2007 09:21:41 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html
really missed up
]]> contact@nospam.com (Ajay Bhargav) Tue, 05 Jun 2007 10:41:56 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html
as we are doing the timer part right now.. so.. you just have to take care of four switches, which will be connected directly...
the start switch will be an interrupt switch and rest all switches (pause,stop,reset) will be polled when counting. hope you get my point.

» now the thing you suppose to do...
connect these four switches, start switch connected to interrupt pin and other three switches connected to normal pins.
make a program, at every interrupt you start blinking the LED and at stop stop the blinking led, and also pause will pause the blinking, leave the reset for the moment.
Hint: set a flag in interrupt routine which indicate that timer has to start now. and when you enter the timer routine, disable interrupt and start polling the three switches.

after this you are ready with all four switches. Complete this soon.

offtopic: sorry for last night, my internet was not working ]]> contact@nospam.com (Ajay Bhargav) Tue, 05 Jun 2007 23:48:52 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html 1181134627_1340_FT883_design.zip]]> contact@nospam.com (Ajay Bhargav) Wed, 06 Jun 2007 05:57:16 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html Port C of 8255 is bit addressable so connect rows of keypad to it, because its easy to drive and sense. Also it takes lesser time and easy programming.

Regarding connection of 2 7-segment displays, as you have the common anode pin is connected to +5V instead, connect it via transistor and transistor is switched with the help on Port C of 8255, so when you have two seven segments, you first send the data on first one and enable it, after sometime, disable it and enable the second one, when you do this switching faster, it looks like two numbers are getting displayed.
change your connections like this...

connect rows of Keypad to PC0-PC3, two common cathode pins are driven by PC4,PC5 and three switches are connected to PC6-PC8, Columns are connected to PB0-PB2 and seven segments are connected to PA0-PA7. LEDs can be connected to PA6 and PA7. The start button is connected to Interrupt pin. using PIC (programmable interrupt controller) i don't remember the IC i think its 8259. So whenever interrupt occurs the processor will set the flag and timer will start counting. I explained everything regarding what you have to do next... in the previous post

now i think your schematic part is over... please make a nice schematic.

so i hope you will do something.. regarding the above post.]]> contact@nospam.com (Ajay Bhargav) Wed, 06 Jun 2007 07:45:25 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html
i have done a basic design
its attached
would you please see it and tell em what do u think
am using a 8086 processor , but the thing that i cannt figure out are
1- how to connect 2 7 sigma display togather
2-the led to show the minus sign???
how can u help please
3-the assemply code :S
]]> contact@nospam.com (Ajay Bhargav) Wed, 06 Jun 2007 05:54:17 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html (*=x , #=+, 0=-, and the keypad (1111) for /) , i know how can i display the result, i just dont know how can i do the math and read the number and the operation
i really cant thank u enough for your help :):):)]]> contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 08:19:02 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html lol kidding.. its ok brother.. my site, i made it for this purpose only.. for everyone who want any kind of help i am happy that i am able to help you.

ok.. now regarding keypad.. you have to write a small program.. just to read and display the value from keypad. so is like this way...
we have 4 rows, and 3 columns. we will scan the rows one by one...
well i dont know the keypad is constructed, but i will just give you some idea... according to design there in my mind.
you make R0 = 1, by setting the pin connected to row 0 of keypad. then sense the columns connected to PortB for 0. if any of the column is zero then key is pressed.
e.g.
you have pressed number 2. so while sensing... you make R0 = 1 and you read from Port B. you get a value 0x05 it will be better if you AND the read value from Port B with 0x07 so you will just get the value of Pins connected to columns only, reduces the error.
so in binary we will get a value B'00000101' C0 = 1, C1 = 0 and C2 = 1
i.e. in row 1 key 2 is pressed. this way we will do the scan. so when reading from keypad, you make the rows One, one by one first R0 then read the column, then R1 and read the column, then R2, then R3...
i hope you understood the concept of scanning and reading the keypad.
try making a small program just to scan and display the value.. i hope you know how to decode the value for 7-segment. if not then tell me i will explain it here.. ]]> contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 09:06:10 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 09:26:07 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 09:30:50 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html you can do one thing.. more.. like.. press a number and then to confirm the first number press #
and then second number and then # to save the second one..
now press * to select the math function, e.g. if pressed once +, pressed twice then -, thrice * and fourth time ÷
after selecting the function press # to get the result... i think its really simple..
try the simple + and - functions for now.. and tell me the results.. ]]> contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 11:36:13 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html

Regards
]]> contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 12:03:29 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html
bro, i don't remember 8086 programming anymore, really.. but as i know controllers so i am explaining you the concept or the basic behind it..
ok.. lets put it this way.. you said that you are able to get the i/p from keypad in your previous post right?
so.. you can also store the i/p received right?
and.. u can put this keypad routine in a subroutine so whenever you need to read from keypad you just call this routine, µP will work in µSecs so will be faster to process the routines..
what i want is this way.. (i give you the steps because i don't know assembly sorry for this )

clear the register on which number to be stored
get_num:
display number (will be zero in this case. coz starting)
call keypad_routine
store the received number
display it
check if pressed key is #
if yes save the number to some location and jump to second_num
if no then jump back to label get_num: and get the key and current pressed number will be there on the display as well as in the register where u want to store it.
second_num:
same as we did above,
but now we will wait for either #or * to be pressed..
make only + for now..
so if u press * + is selected and then press # to get result.

I am trying my best to explain.. but i really don't have any idea how to do this in microprocessors.. but i am sure you will do it..
please try writing something like what i explained above i am sure you will reach somewhere ]]> contact@nospam.com (Ajay Bhargav) Thu, 07 Jun 2007 12:45:09 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 03:12:18 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html he has a course to do.. so it comes under it.. so is ok.. the way it is..]]> contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 03:23:12 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html
and i think its OK, asking some one, since he didnt give me any code , or hardware EWC]]> contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 03:43:21 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html and u understood my point on the mail perfectly.. and i am very happy!!
that you doing everything on your own.. ]]> contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 03:53:52 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 07:51:09 -0700 http://www.8051projects.net/forum-t883.html Re: Need help in Micro project http://www.8051projects.net/forum-t883.html ]]> contact@nospam.com (Ajay Bhargav) Fri, 08 Jun 2007 08:06:35 -0700 http://www.8051projects.net/forum-t883.html