UGN Security Forums
My ProfileMember DirectoryLogin
Search our ForumsView our FAQView our Site Rules
View our CalendarView our Active TopicsGo to our Main Page

UGN Security Store
 

Network Sites UGN Security, The GoNix Initiative, Elite Web Gamers, Back of the Web, EveryDay Helper, VNC Web Design & Development
August
Su M Tu W Th F Sa
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
Sponsored Links
Latest Postings
Latest Reviews
Topic Options
Rate This Topic
#30106 - 11/11/03 03:52 AM circuit through parallel port
bosky101 Offline
Junior Member

Registered: 10/01/03
Posts: 59
Loc: india
hi..

i ve just started trying out electronics with the parallel port programming with VB...i thought this board might be able to help me out .correct me if i go wrong anywhere ...

so the parallel port has 8 outputs...and i connect that to a pc relay card...

now i need to connect to more than 8 different outputs...ideally by a timer ..
is it possible to have more than 8 outputs?would it wrok if i used shift registers(or a series of flip flops) for a timing circuit ?

thnx..
_________________________
"it is the question ...that drives the answer..."
Keep Clicking,
Bosky

Top
Sponsored Links
      
#30107 - 11/11/03 06:58 AM Re: circuit through parallel port
sinetific Offline
nobody

Registered: 03/02/02
Posts: 815
Loc: Ann Arbor
Yes it is possible to make the 8 outputs into more than 8. What do you need more than 8 outputs for? you might want to try something like demultiplexing.

with demultiplexing, you can have take a small numer of inputs and turn it into a larger output.
Code:
   
     _____
s0--|  D  |-y0
s1--|  E  |-y1
    |  M  |-y2
    |  U  |-y3
X---|  X  |
     ¯¯¯¯¯
Basically you have your data input X. Your cable select lines S. and your outputs Y. The cable select
Determines which output line the input bit will come out on.
00 = y0
01 = y1
10 = y2
11 = y3

s+1(for the data) number inputs will equal s^2 number outputs. and if you cant find chips with enough outputs you can always double them up and use enables and such.

Would this method work for your project or not?

Top
#30108 - 11/12/03 01:27 AM Re: circuit through parallel port
bosky101 Offline
Junior Member

Registered: 10/01/03
Posts: 59
Loc: india
ya thnx sinetific ,this is probably what i could use as an input...

but i needed >8 outputs to connect to well more than 8 LED's ..its just a test...if i figure out the usage with multiple outputs...i can plan out better...

i was thinking this output limited to 8 might be a prob.... but u say it isnt.... fine..

few Q's
1.can i use say ...two for input, 6 for output at the same time ?

2. will something like this work ...

- input from parallel port to 9 ouput led's
- since all inputs are given thru the same input,what kind of circuit shud i use to continiously switch this input to consecutive outputs..
do ihave any ohter option ?...

u get the idea rite !

thnx...
_________________________
"it is the question ...that drives the answer..."
Keep Clicking,
Bosky

Top
#30109 - 11/12/03 04:27 AM Re: circuit through parallel port
sinetific Offline
nobody

Registered: 03/02/02
Posts: 815
Loc: Ann Arbor
No i don't say it's not a problem. I have no idea what your trying to do. oyu need to give me the bigger picture of what your making so I can get a proper idea of what you will need. and no i dont really get the idea fromy our broken english and bad grammer.

Top
#30110 - 11/12/03 05:03 AM Re: circuit through parallel port
Gremelin Offline

Community Owner
*****

Registered: 02/28/02
Posts: 7192
Loc: Portland, OR; USA
pssst, he's making a light to show off to his friends...
_________________________
Donate to UGN Security here.
UGN Security, Back of the Web, Elite Web Gamers & VNC Web Design Owner

Top
#30111 - 11/12/03 05:16 PM Re: circuit through parallel port
bosky101 Offline
Junior Member

Registered: 10/01/03
Posts: 59
Loc: india
all right ppl...

its not exactly a haloween spoof im trying if thats what gizmo was trying to 'hint' .

i 'm trying to connect my parallel port to multiple seven segment displays...

that looks like this

in case ur thinking what kind of seven segment display it is ....


so each of the inputs would go to each side..
so if i wanna make the number '5'
id go for the inputs
a->1, f->1 ,
g->1 , c->1 ,d->1

i want ...say 5 of these individual displays...so that i can use this as a mini display ! thats why i need so many ouputs,the prob is that i have only 1 source of input - the parallel port...so how do i manage the flow of inputs... do i use a flip flop/shift register to pass the flow to next display?

say i wanna pass the number : 12345 (assume ther 5 seven segment displays)

after displaying the first seven segment display , u need to move to the next display automatically till all 5 are displayed ...

now...where were we ...
_________________________
"it is the question ...that drives the answer..."
Keep Clicking,
Bosky

Top
#30112 - 11/13/03 09:39 PM Re: circuit through parallel port
sinetific Offline
nobody

Registered: 03/02/02
Posts: 815
Loc: Ann Arbor
ok smartass, we all know what 7 segment displays are. Anyways use 3 demultiplexers (2 and 1/2 you might as well just make it six displays it will be just as easy.) and some flipflops to hold the data. Then your code will be 8 bits long to make one segment display. which will be something like
1 \
0 > Cable select
1 /
1 > enable demux1
0 > enable demux2
0 > enable demux3
1 > data
0 > unused bit.(probably use it for clear for the flip flops)

Anyways here is a brief example (I didnt put any of the flipflops in).


If you want me to make the schematic for you. Just tell me. There are probably about ten other ways of doing this. this is the way I came up with if anyone else has any suggestions feel free.

Top
#30113 - 11/14/03 03:01 AM Re: circuit through parallel port
bosky101 Offline
Junior Member

Registered: 10/01/03
Posts: 59
Loc: india
1)buddy ,what circuit simulation software do u use dude, i think i'll find it vvvvery handy...looks nice and neat..thnx.


2)can u verify if this is the implementation uve given above:
- we have the multi level demux's, which lead to the 7seg inputs...
and what exactly is the schematic ?


3)and buddy,correct me if im wrong ...
shud The input from pll port shud flow thru a counter ,so that only after first 7seg is activated; it goes to second one ;and so on ? how else can u do it ?


cheers...
_________________________
"it is the question ...that drives the answer..."
Keep Clicking,
Bosky

Top
#30114 - 11/15/03 04:51 AM Re: circuit through parallel port
sinetific Offline
nobody

Registered: 03/02/02
Posts: 815
Loc: Ann Arbor
Yeah, that isn't really the schematic for the circuit, but rather just a rough sketch of the idea. If you look closely you can see many errors. I just wnated to show you the idea of how you can have the select go to all 3 demux's and use enable/disable to choose which one will get the data. That wouldnt even come close to working. The software is multisim circuit design and emulator.I was thinking you would be controlling timing with the software. the timing delays between ICs will be in microseconds. Im not the best circuit designer, but im working on it.

Top
#30115 - 04/30/04 05:21 PM Re: circuit through parallel port
n0mel Offline
Junior Member

Registered: 04/30/04
Posts: 34
Loc: ...
heheh...with that type of setup, only one segment of each 7 segment display could be lit up at once. not a problem, you'd just have to cycle through constantly. so, to keep it above 50 - 60 Hz (which is where our eye's can handle flicker without being annoying), and have 8,8,8,8,8, you would need to update 49 segments once every 1/50 of a second. that would mean or, do an update every 1/2450th of a second, or 408us. the parallel port could easily do this, but, there are easier ways.

There are chips made for 7 segment displays. The input side takes a binary number. The output side connects directly to the 7 segment display. when you feed the ic a binary number, it will light up the display with that number. all i've seen even support 7.5 segment displays (the ones that include the period after the number.

Top

Featured Member
Registered: 03/05/02
Posts: 9
Forum Stats
2146 Members
46 Forums
33849 Topics
69016 Posts

Max Online: 1567 @ 04/25/10 10:20 AM
Top Posters
UGN Security 27012
Gremelin 7192
§intå× 3255
SilentRage 1273
Ice 1146
pergesu 1136
Infinite 1041
jonconley 955
Girlie 908
unreal 860
Newest Members
Devo60, ali, lavos, Zanvin Green, Daktologist
2145 Registered Users
Who's Online
0 registered (), 315 Guests and 325 Spiders online.
Key: Admin, Global Mod, Mod
Latest News


Donate
  Get Firefox!
Get FireFox!