Anyone know of a PIC based frequency counter using the low current 7 segment
readouts as in the Elecraft KX-1? Size, durability and I drain are the
important factors here- LCD displays are not an option.

Tnx,

Dale W4OP

On Wed, 11 Feb 2004 13:47:22 GMT, "Dale Parfitt"
wrote:

Anyone know of a PIC based frequency counter using the low current 7 segment
readouts as in the Elecraft KX-1? Size, durability and I drain are the
important factors here- LCD displays are not an option.

have a look at...
http://www.qsl.net/om3cph/om3cph.html
it may be what you are looking for

On Wed, 11 Feb 2004 13:47:22 GMT, "Dale Parfitt"
wrote:

Anyone know of a PIC based frequency counter using the low current 7 segment
readouts as in the Elecraft KX-1? Size, durability and I drain are the
important factors here- LCD displays are not an option.

have a look at...
http://www.qsl.net/om3cph/om3cph.html
it may be what you are looking for

In article , "Dale Parfitt"
writes:

Anyone know of a PIC based frequency counter using the low current 7 segment
readouts as in the Elecraft KX-1? Size, durability and I drain are the
important factors here- LCD displays are not an option.

A problem there is finding an LED numeric display with low current
per segment or a driver capable of higher peak current for sequential
strobing of an array of LEDs. The only thing that I could recommend
is the miniature LED array with integral magnifying lens and filter that
HP made for their first scientific calculator, the HP-35.

In the HP 1979 Optoelectronic databook, the 5082-7200 series and
5082-7400 series have varying numeric character assemblies from
2 to 16 digits. The 5082-7240 is an 8-digit assembly "capable of
being driven by MOS circuits" (according to catalog text, apparently
in reference to calculator use). Average per segment current is
about 0.5 mA and peak current (for strobing array) is 5.0 mA. The
character height is 2.59mm by 1.52mm wide but magnified by the
integral plastic lens. I've stared at that HP-35 calculator display
long enough without eyestrain from the appearance (only headaches
from results not meeting expectations). Brightness is okay to use
in a well-lighted office environment but gets a bit dim outdoors in the
shade (such as a QRP outing?).

I don't know if they are made any more, couldn't get through the
Agilent-HP site to find them. Someone makes those little LED
numeric arrays now, used in hand-carried frequency counters.

A PIC would strobe segments and the program could be adjusted
to optimize the on-time duty cycle for a particular segment. In using
unmagnified LEDs, the average segment current is around 5 mA
minimum for sufficient brightness but that is variable depending on
the molded-in filtering for various colors (attenuates brightness).
Strobing would require higher peak currents.

Len Anderson
retired (from regular hours) electronic engineer person

Hey! I think I have some of those. Since I'm never going to use them, I
suppose I could part with them.

But first the obligitory assesment of assumptions: Why are LCD displays not
an option? Could you drive an LCD from your PIC? I've seen info on this
from the LCD manufacturers; it looks quite doable from a PIC.

"Avery Fineman" wrote in message
...
In article , "Dale Parfitt"
writes:

Anyone know of a PIC based frequency counter using the low current 7
segment
readouts as in the Elecraft KX-1? Size, durability and I drain are the
important factors here- LCD displays are not an option.

A problem there is finding an LED numeric display with low current
per segment or a driver capable of higher peak current for sequential
strobing of an array of LEDs. The only thing that I could recommend
is the miniature LED array with integral magnifying lens and filter
that
HP made for their first scientific calculator, the HP-35.

In the HP 1979 Optoelectronic databook, the 5082-7200 series and
5082-7400 series have varying numeric character assemblies from
2 to 16 digits. The 5082-7240 is an 8-digit assembly "capable of
being driven by MOS circuits" (according to catalog text, apparently
in reference to calculator use). Average per segment current is
about 0.5 mA and peak current (for strobing array) is 5.0 mA. The
character height is 2.59mm by 1.52mm wide but magnified by the
integral plastic lens. I've stared at that HP-35 calculator display
long enough without eyestrain from the appearance (only headaches
from results not meeting expectations). Brightness is okay to use
in a well-lighted office environment but gets a bit dim outdoors in the
shade (such as a QRP outing?).

I don't know if they are made any more, couldn't get through the
Agilent-HP site to find them. Someone makes those little LED
numeric arrays now, used in hand-carried frequency counters.

A PIC would strobe segments and the program could be adjusted
to optimize the on-time duty cycle for a particular segment. In using
unmagnified LEDs, the average segment current is around 5 mA
minimum for sufficient brightness but that is variable depending on
the molded-in filtering for various colors (attenuates brightness).
Strobing would require higher peak currents.

Len Anderson
retired (from regular hours) electronic engineer person

"Tim Wescott" wrote in message
...

But first the obligitory assesment of assumptions: Why are LCD displays
not
an option? Could you drive an LCD from your PIC? I've seen info on this
from the LCD manufacturers; it looks quite doable from a PIC.

I was wondering that myself. It's a whole bunch lower power than LEDs,
which seemed to be a requirement, and the circuitry is a pile simpler. The
one requirement he did have was "durability" that maybe you could argue LEDs
had a leg up on. Well, maybe with those teeny LED displays you could keep
the size smaller than an LCD, but I suspect you would more than make up for
it in drive circuitry, unless maybe he's thinking surface mount.

Oh, and driving an LCD is a piece of cake from a PIC.

...

"xpyttl" wrote in message
...
"Tim Wescott" wrote in message
...

But first the obligitory assesment of assumptions: Why are LCD displays
not
an option? Could you drive an LCD from your PIC? I've seen info on
this
from the LCD manufacturers; it looks quite doable from a PIC.

I was wondering that myself. It's a whole bunch lower power than LEDs,
which seemed to be a requirement, and the circuitry is a pile simpler.
The
one requirement he did have was "durability" that maybe you could argue
LEDs
had a leg up on. Well, maybe with those teeny LED displays you could keep
the size smaller than an LCD, but I suspect you would more than make up
for
it in drive circuitry, unless maybe he's thinking surface mount.

Oh, and driving an LCD is a piece of cake from a PIC.

..I appreciate all the comments. The glass cases of the LCD- aside from
being large, is a bit fragile. This is going in a very small trail ready
radio- that may have to survive falls from 3000' rock cliffs. Already lost
an LCD that way.

Dale W4OP

Dale Parfitt wrote:


..I appreciate all the comments. The glass cases of the LCD- aside from

being large, is a bit fragile. This is going in a very small trail ready
radio- that may have to survive falls from 3000' rock cliffs. Already lost
an LCD that way.

Dale W4OP

Wow
I suspect not much would survive that sort of fall
My counter at http://members.iinet.net.au/~richardh/VK6BRO.htm
takes less than 10 mA
The LCD module is probably as rugged as a LED setup, particularly if you
have to mount individual displays and drivers opn a board
Unfortunately I have sold all the current boards but the software and
circuitry is there.
It uses a AVR rather than a PIC

Richard

At first I thought you wanted a counter, but it sounds more like a frequency
display for a rig is what you are looking for.

If you're madly in love with LEDs, you may want something like that one
digit counter that I think was in QST a few years back. Understand that
LEDs are current hungry and require relatively complex support circuitry
compared to LCDs. You can reduce both of these by cutting down the number
of digits. You can also add some complexity, either in software or
circuitry, to help with the current drain, but finding something that will
likely work with your radio is improbable .. to get the combination you are
going to have to do some of the design work yourself. You will also be
challenged in trading off the current for brightness. I suspect (can't say
I know for sure) that making an LED display work at low current at a
brightness level you could use outdoors in the daytime is going to be
something of a problem.

That being said, what about something like Dave Fifield's AFA or Dave
Benson's Freq-Mite? This gets you way smaller and lighter than your LEDs,
and certainly no less durable. And the current consumption will be orders
of magnitude less than even the most carefully implemented LEDs. You don't
get the warm, red glow, but you get the frequency in a fraction of the
size/weight/current. And for twenty bucks you avoid the whole design/parts
procurement exercise.

...

"Dale Parfitt" wrote in message
...

"xpyttl" wrote in message
...
"Tim Wescott" wrote in message
...

But first the obligitory assesment of assumptions: Why are LCD
displays
not
an option? Could you drive an LCD from your PIC? I've seen info on
this
from the LCD manufacturers; it looks quite doable from a PIC.

I was wondering that myself. It's a whole bunch lower power than LEDs,
which seemed to be a requirement, and the circuitry is a pile simpler.
The
one requirement he did have was "durability" that maybe you could argue
LEDs
had a leg up on. Well, maybe with those teeny LED displays you could
keep
the size smaller than an LCD, but I suspect you would more than make up
for
it in drive circuitry, unless maybe he's thinking surface mount.

Oh, and driving an LCD is a piece of cake from a PIC.

..I appreciate all the comments. The glass cases of the LCD- aside from
being large, is a bit fragile. This is going in a very small trail ready
radio- that may have to survive falls from 3000' rock cliffs. Already lost
an LCD that way.

Dale W4OP

Dale Parfitt wrote:


..I appreciate all the comments. The glass cases of the LCD- aside from

being large, is a bit fragile. This is going in a very small trail ready
radio- that may have to survive falls from 3000' rock cliffs. Already lost
an LCD that way.

Dale W4OP

Wow
I suspect not much would survive that sort of fall
My counter at http://members.iinet.net.au/~richardh/VK6BRO.htm
takes less than 10 mA
The LCD module is probably as rugged as a LED setup, particularly if you
have to mount individual displays and drivers opn a board
Unfortunately I have sold all the current boards but the software and
circuitry is there.
It uses a AVR rather than a PIC

Richard