Digest Number 1607
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Hello Sadler:
I have been using the Allegro 6276 with a PIC, but there are no timing issues so
it should work fine with a stamp.
http://www.allegromicro.com/sf/6276/
This is a serial in chip that will drive 16 LEDs, 2 each 7-segment displays
(including the decimal point) or one 14 or 16 segment alphanumeric LED display.
The displays must be Common Anode since the 6276 contains a current sinking
regulator for each LED. Note that the LEDs are driven in a static way, NOT
multiplexed. There is a single resistor used to set the current for all 16
LEDs. Note that multiplexing requires higher drive current [noparse][[/noparse]by SQRT(n)] then Dc
drive and is less efficient.
The 4 drive lines are: Data In, Clock In, Output Enable and Latch Enable. There
is also a Data Out so the chips can be cascaded. In my case I tie the Latch
Enable high and only use 3 I/O pins to drive as many digits as I want.
I have a PCB on order that will hold 6 each 0.56" char. ht. 7-segment LEDs and
the 3 each 6276 chips. The board is designed so that they can be cascaded using
8 pin headers to form displays of 6, 12, 18, 24 digits, or whatever. Of course
the power for the LEDs needs to be adequate. I'm thinking of also making boards
for larger LEDs. You can see a 6 digit clock using this method of display at:
http://brooke.mystarband.net/images/67576E.jpg Note the small number of parts
needed.
MAX7219 $ 3.99 @ 1,000
A6276 $ 1.29 @ 1,000
If you're interested in any of these boards please let me know.
Thanks,
Brooke Clarke, N6GCE
http://www.prc68.com
> Date: Fri, 24 Jan 2003 14:21:24 -0500
> From: Sadler Porter <porter.sadler@s...>
> Subject: 7 Segment Displays
>
> Is there a chip which decodes byte or nibble to 7 segment displays and
> handle the repeated strobing of the digit display .
> I want to write out 4 characters to a set of 4x 7 segs using a stamp and not
> worry about the overhead
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
> ________________________________________________________________________
[noparse][[/noparse]Non-text portions of this message have been removed]
I have been using the Allegro 6276 with a PIC, but there are no timing issues so
it should work fine with a stamp.
http://www.allegromicro.com/sf/6276/
This is a serial in chip that will drive 16 LEDs, 2 each 7-segment displays
(including the decimal point) or one 14 or 16 segment alphanumeric LED display.
The displays must be Common Anode since the 6276 contains a current sinking
regulator for each LED. Note that the LEDs are driven in a static way, NOT
multiplexed. There is a single resistor used to set the current for all 16
LEDs. Note that multiplexing requires higher drive current [noparse][[/noparse]by SQRT(n)] then Dc
drive and is less efficient.
The 4 drive lines are: Data In, Clock In, Output Enable and Latch Enable. There
is also a Data Out so the chips can be cascaded. In my case I tie the Latch
Enable high and only use 3 I/O pins to drive as many digits as I want.
I have a PCB on order that will hold 6 each 0.56" char. ht. 7-segment LEDs and
the 3 each 6276 chips. The board is designed so that they can be cascaded using
8 pin headers to form displays of 6, 12, 18, 24 digits, or whatever. Of course
the power for the LEDs needs to be adequate. I'm thinking of also making boards
for larger LEDs. You can see a 6 digit clock using this method of display at:
http://brooke.mystarband.net/images/67576E.jpg Note the small number of parts
needed.
MAX7219 $ 3.99 @ 1,000
A6276 $ 1.29 @ 1,000
If you're interested in any of these boards please let me know.
Thanks,
Brooke Clarke, N6GCE
http://www.prc68.com
> Date: Fri, 24 Jan 2003 14:21:24 -0500
> From: Sadler Porter <porter.sadler@s...>
> Subject: 7 Segment Displays
>
> Is there a chip which decodes byte or nibble to 7 segment displays and
> handle the repeated strobing of the digit display .
> I want to write out 4 characters to a set of 4x 7 segs using a stamp and not
> worry about the overhead
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
> ________________________________________________________________________
[noparse][[/noparse]Non-text portions of this message have been removed]