Binary to decimal: how to send 8 bits to 2 displays or ...?

[Tari]

Hello!

I'm working on a project that requires to display binary words (8
bits) on a 7-segment display. It is the purpose to show those words
decimally. Anyone knows of a device that can convert an 8 bit word
into the correspondent decimal numbers (0, 1, 2, ..., 9, 10, ..., 64
(that's where I have to set a reset))?
I was thinking of using 2 displays, but I don't know how to deal with
it. Or does there exists a 7-segment-display that exists of 2 parts,
so that you automatically can show numbers like 20 etc. ?

I hope some one can help me.
Thanks in advance!

Greetings
Tari

 

[Richard Hosking]

Tari
It might be easiest to represent the 8 bit word as a 2 digit Hexadecimal
number. If you *must* represent it as a decimal, it will take three digits
(000-255) and some significant logic to convert from binary to decimal. The
simplest way I can think of to do this would be to use a microcontroller
which could also drive the display. Is this a possibility?

Richard

Tari <snuffie_456@yahoo.com> wrote in message
news:a56dfbff.0308250524.3a5f44fa@posting.google.com...

Hello!

I'm working on a project that requires to display binary words (8
bits) on a 7-segment display. It is the purpose to show those words
decimally. Anyone knows of a device that can convert an 8 bit word
into the correspondent decimal numbers (0, 1, 2, ..., 9, 10, ..., 64
(that's where I have to set a reset))?
I was thinking of using 2 displays, but I don't know how to deal with
it. Or does there exists a 7-segment-display that exists of 2 parts,
so that you automatically can show numbers like 20 etc. ?

I hope some one can help me.
Thanks in advance!

Greetings
Tari

 

[Fred Abse]

On Mon, 25 Aug 2003 14:24:40 +0100, Tari wrote:

Hello!

I'm working on a project that requires to display binary words (8 bits)
on a 7-segment display. It is the purpose to show those words decimally.
Anyone knows of a device that can convert an 8 bit word into the
correspondent decimal numbers (0, 1, 2, ..., 9, 10, ..., 64 (that's
where I have to set a reset))? I was thinking of using 2 displays, but I
don't know how to deal with it. Or does there exists a 7-segment-display
that exists of 2 parts, so that you automatically can show numbers like
20 etc. ?

Quick and dirty method for a one-off:

State table in 16-bit EPROM, or two 8-bit EPROMS. Drive the address lines
with the input byte and use the data lines (buffered) to drive two
7-segment displays.

Breadboard it in an hour. Write the state table in ten minutes.

Use those 4716s you never could bring yourself to throw away

Otherwise you could use a couple of 74*185 binary to BCD converters,
then two 74*49 BDC to 7-segment decoder/drivers driving two 7-segment
displays.

There's lots of other ways of doing it, but since it looks like a school
project, I'll leave you to find those out yourself.


--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Martin Riddle]

Think Bitmap.
Make a table like this:
{0,0x3f},
{1,0x06},
{2,0x5b},
{3,0x4f},
{4,0x66},
{5,0x6d},
{6,0x7c},
{7,0x07},
{8,0x7f},
{9,0x67},
{10,0x77},
{11,0x7C},
{12,0x58},
{13,0x5E},
{14,0x79},
{15,0x71}};

Wherethe HEX values represent the segment leds. THis table is for 0-F on a seven seg display. It
depends on how you have the digits hooked up, ie what bit is tied to what segment. And if the Digit
is Common Anode or Cathode. Just index into the table for the correct bitmap.
And as someone pointed out you can use an EPROM to be a character generator.

Good luck

"Tari" <snuffie_456@yahoo.com> wrote in message
news:a56dfbff.0308250524.3a5f44fa@posting.google.com...

Hello!

I'm working on a project that requires to display binary words (8
bits) on a 7-segment display. It is the purpose to show those words
decimally. Anyone knows of a device that can convert an 8 bit word
into the correspondent decimal numbers (0, 1, 2, ..., 9, 10, ..., 64
(that's where I have to set a reset))?
I was thinking of using 2 displays, but I don't know how to deal with
it. Or does there exists a 7-segment-display that exists of 2 parts,
so that you automatically can show numbers like 20 etc. ?

I hope some one can help me.
Thanks in advance!

Greetings
Tari

 

[Tony Williams]

In article <a56dfbff.0308250524.3a5f44fa@posting.google.com>,
Tari <snuffie_456@yahoo.com> wrote:

I'm working on a project that requires to display binary words (8
bits) on a 7-segment display. It is the purpose to show those
words decimally. Anyone knows of a device that can convert an 8
bit word into the correspondent decimal numbers (0, 1, 2, ..., 9,
10, ..., 64 (that's where I have to set a reset))?

Set a reset? Sounds like you might be coming from a counter.
If so don't use a binary counter, use a 2-digit BCD counter.
Each digit then goes directly to a BCD-7segment display/driver.

If it has to be a binary input then the old microprocesser
logic would be..... Split the binary D7-D0 into two nibbles,
D7-D4 is hi-nib and D3-D0 is lo-nib. Look at lo-nib.

If lo-nib is less than 9, then the two BCD output digits are
simply hi-nib and lo-nib. If lo-nib is greater than 9, then
the two BCD output digits are (hi-nib + 1) and (lo-nib + 6).

This could be done in hardware (1x 4-bit magnitude comparator,
and 2x 4-bit adders), or in software in a microprocessor.
A little 18-pin PIC has just about enough i/o to do it.

--
Tony Williams.