Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

how to interface 28 I/O ports with PC?

Status
Not open for further replies.

hf2050

Member level 2
Joined
Nov 27, 2001
Messages
48
Helped
2
Reputation
4
Reaction score
0
Trophy points
1,286
Activity points
287
28 I/O ports ?

Hi!

Any idea how to build some PC interface (via rs232, paralel port or ISA/PCI card) with 28 I/O lines or maybe some MCU with 28 I/O ports ?
Need to control 7 BCD coded slots .

Thanks !
 

Ace-X

Advanced Member level 2
Joined
Jan 25, 2002
Messages
529
Helped
41
Reputation
82
Reaction score
14
Trophy points
1,298
Location
Germany
Activity points
5,150
Here are some ways:
1. There are a lot of 51 uC with 4 8-bits ports, like Atmel 8252. Also, PICs in 40 pins package will work. It is better to use SPI software emulation through the parallel port to connect them.
2. You can also use simple CPLD from Xilinx or Altera. They have enough pins to be connected to parallel port.
3. You can use cheap network PCI card to re-design it to a simple PCI IO card. After that you'll get a plenty of resourses for IO.

Cost of all these solution is about 5-7 $.

Hope it will help!

Ace-X.
 

Bat

Member level 1
Joined
Dec 15, 2002
Messages
35
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
348
Or you can use these old things 8) called 'latches' (74x373 or 74x374)
There are 8+4 pin usable in output on the parallel port

With 4 latches, it takes 4 pin two drive the latch, and 8 bits of data.

=>32 ouput
 

newmania

Member level 1
Joined
Sep 29, 2002
Messages
37
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
228
You can connect more latches with decoder chip. And use 64, 96 or more output. If you have bidirectional parallel port you can use ports as input too.
 

hitajian

Junior Member level 3
Joined
May 26, 2001
Messages
30
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
144
The MCU from fujistu have enough I/Os .
9x8 !
The MB90540 serias.
 

Epegic

Member level 5
Joined
Mar 29, 2002
Messages
84
Helped
24
Reputation
46
Reaction score
19
Trophy points
1,288
Activity points
597
You can wire two 8255 to printer port and got 48 IO pins. Connect one 8255 does not need any extra logic chip if you accept 24 IO.
 

year

Member level 3
Joined
Feb 21, 2002
Messages
62
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
441
As my experience, 8255 was not robust.
You may check TTL IC (LS244 or something).
 

Arrek

Newbie level 2
Joined
Jun 12, 2003
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
20
Bat said:
Or you can use these old things 8) called 'latches' (74x373 or 74x374)
There are 8+4 pin usable in output on the parallel port

With 4 latches, it takes 4 pin two drive the latch, and 8 bits of data.

=>32 ouput
only '373 is latch, '374 contains 8xD (it's not the same, but can be used interchangeably in many cases)
better to use 573 or 574 - this have more "friendly" pinset.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top