How hard would this be to make?

[John Comma Smith]

I got a bit of a weird request for circuit people out there. I want to make
a display out of LEDs. I'm not sure of the size of the display as of yet,
but I want to be able to program the LEDs to blink in a random fashion,
scroll text across them, or a combination of that. How hard of a circuit
would this be to build, and what would be the best chip to program from my
computer? Thanks in advance.

 

[peterken]

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35oql1F4o25skU1@individual.net...

I got a bit of a weird request for circuit people out there. I want to
make
a display out of LEDs. I'm not sure of the size of the display as of yet,
but I want to be able to program the LEDs to blink in a random fashion,
scroll text across them, or a combination of that. How hard of a circuit
would this be to build, and what would be the best chip to program from my
computer? Thanks in advance.

- put the leds in a matrix
- use a microcontroller for the sequence
(needs "calculation" in case of text)
- control them at rather high frequency, so ni flickering occurs


or just buy an existing module... :-D

 

[John Comma Smith]

"peterken" <peter273@hotmail.com> wrote in message
news0KJd.5235$XE6.634093@phobos.telenet-ops.be...

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35oql1F4o25skU1@individual.net...
I got a bit of a weird request for circuit people out there. I want to
make
a display out of LEDs. I'm not sure of the size of the display as of
yet,
but I want to be able to program the LEDs to blink in a random fashion,
scroll text across them, or a combination of that. How hard of a circuit
would this be to build, and what would be the best chip to program from
my
computer? Thanks in advance.




- put the leds in a matrix
- use a microcontroller for the sequence
(needs "calculation" in case of text)
- control them at rather high frequency, so ni flickering occurs


or just buy an existing module... :-D

I was thinking of buying an existing one but do they make them in a 5 x 19
LED size? How would I go about making a matrix for the LEDs and what type of
microcontroller would you suggest? Thanks.

 

[peterken]

"peterken" <peter273@hotmail.com> wrote in message
news:6yWJd.6065$6F6.645370@phobos.telenet-ops.be...


don't know what sizes of display exist, I think many varieties do
try googling for it

using an electric matrix of 8x8 lines gives 64 possible led's
this only uses 2 processor ports directly
OR
using addressable latches only uses one processor port and one address
decoder
using 2 8-bit latches gives you again a matrix of 64 leds
the controller to be used can be any kind but must have enough ports
- at least 1 if using addressable latches
or
-(number of leds)/64 * 2 ports if controlling directly (=this number is
identical to the number of latches if used)
and enough calculation power to do the job
the needed power of the controller is related to the number of leds to
be
connected since they must be calculated to be on or off and to create a
smooth image if moving

principle of the leds: (2x2 lines depicted)

B1 B2
| |
| |
A1 ---+--------+-----
\ | \ |
\| \|
+ +
A2 ---+--------+-----
\ | \ |
\| \|
+ +
| |

all leds are connected as the diagonal lines are drawn
all leds arranged in same polarity (direction)
so 2x2 lines gives you 4 led's to control (and one half port or latch to
be
used)




"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35u1idF4p8urdU1@individual.net...
This doesn't seem all that hard to do. Do you know of a website that shows
this in more detail?

examples:
http://www.armory.com/~spcecdt/electronics/LED_matrix/
http://www.acm.uiuc.edu/sigarch/tutorials/ledarray/
http://www.maxim-ic.com/appnotes.cfm/appnote_number/1033
http://www.cse.psu.edu/~cg473/Documents/LED%20Matrix.PDF

or just take google, search for led + matrix
gives about 4million results :-D

 

[peterken]

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35q9etF4pn3urU1@individual.net...

"peterken" <peter273@hotmail.com> wrote in message
news0KJd.5235$XE6.634093@phobos.telenet-ops.be...

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35oql1F4o25skU1@individual.net...
I got a bit of a weird request for circuit people out there. I want to
make
a display out of LEDs. I'm not sure of the size of the display as of
yet,
but I want to be able to program the LEDs to blink in a random
fashion,
scroll text across them, or a combination of that. How hard of a
circuit
would this be to build, and what would be the best chip to program
from
my
computer? Thanks in advance.




- put the leds in a matrix
- use a microcontroller for the sequence
(needs "calculation" in case of text)
- control them at rather high frequency, so ni flickering occurs


or just buy an existing module... :-D



I was thinking of buying an existing one but do they make them in a 5 x 19
LED size? How would I go about making a matrix for the LEDs and what type
of
microcontroller would you suggest? Thanks.

don't know what sizes of display exist, I think many varieties do
try googling for it

using an electric matrix of 8x8 lines gives 64 possible led's
this only uses 2 processor ports directly
OR
using addressable latches only uses one processor port and one address
decoder
using 2 8-bit latches gives you again a matrix of 64 leds
the controller to be used can be any kind but must have enough ports
- at least 1 if using addressable latches
or
-(number of leds)/64 * 2 ports if controlling directly (=this number is
identical to the number of latches if used)
and enough calculation power to do the job
the needed power of the controller is related to the number of leds to be
connected since they must be calculated to be on or off and to create a
smooth image if moving

principle of the leds: (2x2 lines depicted)

B1 B2
| |
| |
A1 ---+--------+-----
\ | \ |
\| \|
+ +
A2 ---+--------+-----
\ | \ |
\| \|
+ +
| |

all leds are connected as the diagonal lines are drawn
all leds arranged in same polarity (direction)
so 2x2 lines gives you 4 led's to control (and one half port or latch to be
used)

 

[John Comma Smith]

This doesn't seem all that hard to do. Do you know of a website that shows
this in more detail?

"peterken" <peter273@hotmail.com> wrote in message
news:6yWJd.6065$6F6.645370@phobos.telenet-ops.be...

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35q9etF4pn3urU1@individual.net...

"peterken" <peter273@hotmail.com> wrote in message
news0KJd.5235$XE6.634093@phobos.telenet-ops.be...

"John Comma Smith" <JCSforindependence@yahoo.com> wrote in message
news:35oql1F4o25skU1@individual.net...
I got a bit of a weird request for circuit people out there. I want
to
make
a display out of LEDs. I'm not sure of the size of the display as of
yet,
but I want to be able to program the LEDs to blink in a random
fashion,
scroll text across them, or a combination of that. How hard of a
circuit
would this be to build, and what would be the best chip to program
from
my
computer? Thanks in advance.




- put the leds in a matrix
- use a microcontroller for the sequence
(needs "calculation" in case of text)
- control them at rather high frequency, so ni flickering occurs


or just buy an existing module... :-D



I was thinking of buying an existing one but do they make them in a 5 x
19
LED size? How would I go about making a matrix for the LEDs and what
type
of
microcontroller would you suggest? Thanks.



don't know what sizes of display exist, I think many varieties do
try googling for it

using an electric matrix of 8x8 lines gives 64 possible led's
this only uses 2 processor ports directly
OR
using addressable latches only uses one processor port and one address
decoder
using 2 8-bit latches gives you again a matrix of 64 leds
the controller to be used can be any kind but must have enough ports
- at least 1 if using addressable latches
or
-(number of leds)/64 * 2 ports if controlling directly (=this number is
identical to the number of latches if used)
and enough calculation power to do the job
the needed power of the controller is related to the number of leds to be
connected since they must be calculated to be on or off and to create a
smooth image if moving

principle of the leds: (2x2 lines depicted)

B1 B2
| |
| |
A1 ---+--------+-----
\ | \ |
\| \|
+ +
A2 ---+--------+-----
\ | \ |
\| \|
+ +
| |

all leds are connected as the diagonal lines are drawn
all leds arranged in same polarity (direction)
so 2x2 lines gives you 4 led's to control (and one half port or latch to
be
used)