8086 based project help

[minorit_report]

i hav 2 design a voting machine , which has provision for 8 candidates .It has 2 store the total count and display it on 7 seg display. However , 2 put in use it must b enabled by 8 agents and 1 officer , if any1 is missing it shudn't b enabled. please help me how 2 design the hardware for this
project . thanks

 

[panic mode]

get the datasheet for the one part you know, read it and use it to complete the circuit.

 

[trash]

One old XT motherboard with a printer port should be the only part required

 

[panic mode]

LOL,

well not really, there is still need for memory, power supply, DIN keyboard etc.

 

[minorit_report]

the voting machine has to stop taking input after 10 hrs.So , I thought i can use a timer 8253/8254 by storing a count in it , after 10hrs the gate output of timer wud go high , so wer shud i connect dis output pin to? or shud i make use of interrupt?
PS:-i m using 8086 microprocessor, 8255 ppi , 8253/8254 timer . please suggest something

 

[panic mode]

well that is one way to do it. you can use 8255 I/O to control and read timer

 

[minorit_report]

it has 2 b desiged such that , it must stop taking input after 10hrs . So , do i need to raise an interrupt at the end ?

 

[panic mode]

you have processor at your disposal. you can use it in many ways. one way is to ignore inputs before or after some event. better is to ignore SOME inputs after particular event. i would consider making program like a state machine, for example:

step 0 : reset everything (like upon powerup)
step 1 : start, wait for enable (from agents and officer or whatever)
step 2 : start timer (voting begins)
step 3 : collect votes (and timer complete bit)
step 4 : display count
step 5 : if not timeout, goto step3
step 6 : reached timeout, voting completed
step 7 : indicate voting completed and wait for reset
step 8 : goto step0

then even though you are reading inputs continuously (step 3) there is no problem with votes before voting starts or after voting ends. this is accomplished by structure of program. you need to plan what you want to do, work it out and then implement.

 

[minorit_report]

I m using 8254 as a timer .In step 5 , how will i know that timer has reached its timeout ?

 

[panic mode]

you may be missing some info in your post, for example there should be schematic and some code to start with

 

[koolguy]

Hi,

I have no idea of 8086 based EVM but i have done this project gain after my school to college in first year.
here is the video and some pic.
the working was based on all logic circuit without any controllers!!

https://www.youtube.com/watch?v=M9mEMXMPnQU&feature=player_embedded
**broken link removed**

 

[minorit_report]

At the beginning , i hav loaded a count in the timer such that its output will go high in 10hrs.As soon as the output goes high , the voting machine has to stop taking votes,
the voting machine has to take input as long as output of timer is low. So , how to design this thing?

 

[panic mode]

sit down, think, plan, break it into smaller tasks, then implement and test one part at a time. so what is your plan and where are you at? what have you accomplished? did you nail down components, design circuit, make circuit? cpu can be connected to peripherals in different ways. therefore you should try to finalize hardware design before you start programming.