Driving LED''s
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--- In basicstamps@y..., "naylor_nick" <naylor_nick@y...> wrote:
> Hello,
> Here is the situation. I am trying to use a Basic Stamp to
> drive a 3.5 digit LED display. Can this be done? I have no idea
> how it coul dbe done. However, I do have an A/D converter IC that
> also has 3.5 digit drivers on it. That is controlled with a
> voltage, 200mV max. Can the basic stamp output a certain voltage
on
> a certain I/O line? Can anyone point me to a website that might
> help me out?
I have built and used a 4 digit LED display using a BS2 and 4
74HCT373 latches. I wired each of the displays to a latch output (7
segments and the decimal point) through current limiting resistors.
The latch inputs were bussed together to the BS2 so that a byte can
be output with one instruction. I used 4 more BS2 pins to strobe the
latches to hold the data for the LED. I then programmed the desired
bit patterns into a lookup table. To display a character I simply
used lookup to load the bit pattern to the output pins and then
strobed the particular latch to hold the data. This gave me complete
software control over all four displays.
I realize this tied up 12 I/O pins but it was a nifty first Stamp
project for me. I used this as an odometer for my truck to keep
track of miles between multiple stops.
Have Fun
Hal
> Hello,
> Here is the situation. I am trying to use a Basic Stamp to
> drive a 3.5 digit LED display. Can this be done? I have no idea
> how it coul dbe done. However, I do have an A/D converter IC that
> also has 3.5 digit drivers on it. That is controlled with a
> voltage, 200mV max. Can the basic stamp output a certain voltage
on
> a certain I/O line? Can anyone point me to a website that might
> help me out?
I have built and used a 4 digit LED display using a BS2 and 4
74HCT373 latches. I wired each of the displays to a latch output (7
segments and the decimal point) through current limiting resistors.
The latch inputs were bussed together to the BS2 so that a byte can
be output with one instruction. I used 4 more BS2 pins to strobe the
latches to hold the data for the LED. I then programmed the desired
bit patterns into a lookup table. To display a character I simply
used lookup to load the bit pattern to the output pins and then
strobed the particular latch to hold the data. This gave me complete
software control over all four displays.
I realize this tied up 12 I/O pins but it was a nifty first Stamp
project for me. I used this as an odometer for my truck to keep
track of miles between multiple stops.
Have Fun
Hal