Why does everyone think that PIC is the only microcontroller or the best
/easiest one? Since PIC needs higher programming voltages and not all PC
serial ports provide enough of it, most of the very easy PIC programmers
dont work. I would suggest you use atmel avr's. A nice programmer for it
can be found here : http://www.xs4all.nl/~sbolt/e-spider_prog.html
A freq counter using avr and logic counters is here :
http://www.myplace.nu/avr/countermeasures/
You can find more stuff when using google.

Cheers,
Ronald

SWbeginner wrote:
I plan on building receivers and a simple frequency counter is needed.
Say 4 to 6 digits, up to about 50 Mhz.


I have seen approaches using:
74HCxxxx logic IC's could be made for $20 but lots of wiring

PIC - not much experience except with 16f84.
how to build programmer for lastest PIC's?


Anyone know of a demo or free digital simulation software with CMOS 4XXX
library? I have Microcap 7 demo but digital library is scarce.

So much has progressed since the MC14553 3 digit counter chips. Do they
even make them?




What frequency range , how accurate, and what do you think of as
inexpensive ?
I have not looked lately but there used to be some that would work up
to about 1.5 Ghz around $ 125 or so that would get you to within a
couple of hundred Hz at 150 mhz.

Hi.

It uses an FPGA (or CPLD) and a clock (DS1075) for time reference. The
parts that i'm using a

Xilinx XC4010XL-PC84

Dallas DS1075-100

The FPGA has everything, it has 1 sec reference using the DS1075 (working at
100Khz), 5 divisors to select range of measurement, display control and
parallel port control.

There are two ways to improve it, one is that I can use the internal FPGA
oscillator, but it has a poor precision, and the other it's to use a
different oscillator, maybe a crystal oscillator.. it can be of any
frequency because that is programmable to the FPGA... that way it would be 1
IC frequency meter.

I will put it the VHDL source in the web with a hand-made schematic, and the
PC software. The VHDL can be synthetized with Xilinx Webpack (free download
from www.xilinx.com) and to program the FPGA you can use Xilinx Parallel
Cable III(schematics for it searching on www.google.com). You can use any
FPGA that has enough room to all the circuits, but I think the software can
suggest you wich one to use.

All of that can be found at

http://www.geocities.com/hernan_sanchez/

I will put the files there this night (3:00 GMT).

Regards,



Hernán Sánchez




"SWbeginner" escribió en el mensaje
...
"Hernán Sánchez" wrote in
:

Hi.

I have just designed one that uses 2 chips, it is controlled by a PC
(parallel port) and it has a software to display measurements.

It works from 1Hz to 80Mhz, and can be improved.. if you want to give
it a try, write me and I will send you the schematics and the software
to play with it. I have one working in a XESS FPGA card, but it
doesn't need all those hardware, just 2 of them.

Regards,

Hernán Sánchez
Sure I like to see it. Which 2 chips does it use?

Hi.

It uses an FPGA (or CPLD) and a clock (DS1075) for time reference. The
parts that i'm using a

Xilinx XC4010XL-PC84

Dallas DS1075-100

The FPGA has everything, it has 1 sec reference using the DS1075 (working at
100Khz), 5 divisors to select range of measurement, display control and
parallel port control.

There are two ways to improve it, one is that I can use the internal FPGA
oscillator, but it has a poor precision, and the other it's to use a
different oscillator, maybe a crystal oscillator.. it can be of any
frequency because that is programmable to the FPGA... that way it would be 1
IC frequency meter.

I will put it the VHDL source in the web with a hand-made schematic, and the
PC software. The VHDL can be synthetized with Xilinx Webpack (free download
from www.xilinx.com) and to program the FPGA you can use Xilinx Parallel
Cable III(schematics for it searching on www.google.com). You can use any
FPGA that has enough room to all the circuits, but I think the software can
suggest you wich one to use.

All of that can be found at

http://www.geocities.com/hernan_sanchez/

I will put the files there this night (3:00 GMT).

Regards,



Hernán Sánchez




"SWbeginner" escribió en el mensaje
...
"Hernán Sánchez" wrote in
:

Hi.

I have just designed one that uses 2 chips, it is controlled by a PC
(parallel port) and it has a software to display measurements.

It works from 1Hz to 80Mhz, and can be improved.. if you want to give
it a try, write me and I will send you the schematics and the software
to play with it. I have one working in a XESS FPGA card, but it
doesn't need all those hardware, just 2 of them.

Regards,

Hernán Sánchez
Sure I like to see it. Which 2 chips does it use?

In article , SWbeginner
writes:

This would be great for me but can it work with LED's. I haven't work with
LCD displays before and don't know which one works.

There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary memory,
and optional backlights. They are driven by ASCII coded character
digital byte-parallel input assemblies. PIC and Atmel based counters
can output ASCII according to count plus including controllable legends
for whatever purpose, all under the microcontroller internal program.

LEDs are fine for bright displays, good for viewing out of the corner of
the eye to note changes when working on something. Microcontrollers
could be reprogrammed to output sequential 7-bar segment signals for
external temporary storage, such as a latch-decoder-driver IC for one
decade's LED. LEDs are also relative power hogs from the local DC
supply compared to the entire LCD assembly (8 digits will take around
0.6 A maximum at 5 VDC to light 8 LEDs). LCD power drain is in the
microwatt range, the drivers of an assembly taking most of the DC
power. Low power demand is the major reason for using LCDs in
small-battery watches and radio clocks.

LED readout is very legacy in digital circuitry. Many-digit LCD
assemblies aren't so common and appear strange because they
haven't been as widely used for as long a time.


You might try Francesco Morgantini's (IK3OIL) PIC freq counter. It's
based on a 16f84 and he will email you the hex code if you request it.
It will run to approx 45 MHz as is and up to 1.5 GHz with a simple
add on prescaler. He has divide functions built in the program (
divide by 10/32/64) and he has also include IF offset if you want to
use the counter as a freq readout. I've etched about 40 boards for
local hams here and every one that has been built has worked without
fail. Total cost has been in the neighborhood of $35.00 including the
prescaler but excluding enclosure. If you want a copy of the circuit
board layout with prescaler, just email me at ww2742 at dragonbbs.com.
As for accuracy, I just adjusted one today for another local ham at
it was within 200 Hz at 440 MHz using a recently calibrated IFR-1200
for a source - that was close enough for me.

Here's his website URL:
http://digilander.libero.it/ik3oil/menu_eng.htm

I will suggest perusing the www.aade.com website to see the counters
available there. Some are available in kit form and they are simple and
elegant, include an LCD assembly for readout. All you need do is hook
up a DC power source and check the timebase against WWV.

Otherwise there are a surprisingly large number of websites concerning
PIC and Atmel based microcontroller counters along with associated
microcontroller program source listings. Any search will turn up dozens
of hits. Modifying the existing programs might take up more time than
you would imagine unless you have lots of Assembler coding
experience.

Len Anderson
retired (from regular hours) electronic engineer person

In article , SWbeginner
writes:

This would be great for me but can it work with LED's. I haven't work with
LCD displays before and don't know which one works.

There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary memory,
and optional backlights. They are driven by ASCII coded character
digital byte-parallel input assemblies. PIC and Atmel based counters
can output ASCII according to count plus including controllable legends
for whatever purpose, all under the microcontroller internal program.

LEDs are fine for bright displays, good for viewing out of the corner of
the eye to note changes when working on something. Microcontrollers
could be reprogrammed to output sequential 7-bar segment signals for
external temporary storage, such as a latch-decoder-driver IC for one
decade's LED. LEDs are also relative power hogs from the local DC
supply compared to the entire LCD assembly (8 digits will take around
0.6 A maximum at 5 VDC to light 8 LEDs). LCD power drain is in the
microwatt range, the drivers of an assembly taking most of the DC
power. Low power demand is the major reason for using LCDs in
small-battery watches and radio clocks.

LED readout is very legacy in digital circuitry. Many-digit LCD
assemblies aren't so common and appear strange because they
haven't been as widely used for as long a time.


You might try Francesco Morgantini's (IK3OIL) PIC freq counter. It's
based on a 16f84 and he will email you the hex code if you request it.
It will run to approx 45 MHz as is and up to 1.5 GHz with a simple
add on prescaler. He has divide functions built in the program (
divide by 10/32/64) and he has also include IF offset if you want to
use the counter as a freq readout. I've etched about 40 boards for
local hams here and every one that has been built has worked without
fail. Total cost has been in the neighborhood of $35.00 including the
prescaler but excluding enclosure. If you want a copy of the circuit
board layout with prescaler, just email me at ww2742 at dragonbbs.com.
As for accuracy, I just adjusted one today for another local ham at
it was within 200 Hz at 440 MHz using a recently calibrated IFR-1200
for a source - that was close enough for me.

Here's his website URL:
http://digilander.libero.it/ik3oil/menu_eng.htm

I will suggest perusing the www.aade.com website to see the counters
available there. Some are available in kit form and they are simple and
elegant, include an LCD assembly for readout. All you need do is hook
up a DC power source and check the timebase against WWV.

Otherwise there are a surprisingly large number of websites concerning
PIC and Atmel based microcontroller counters along with associated
microcontroller program source listings. Any search will turn up dozens
of hits. Modifying the existing programs might take up more time than
you would imagine unless you have lots of Assembler coding
experience.

Len Anderson
retired (from regular hours) electronic engineer person

(Avery Fineman) wrote in


There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary
memory, and optional backlights. They are driven by ASCII coded
character digital byte-parallel input assemblies. PIC and Atmel
based counters can output ASCII according to count plus including
controllable legends for whatever purpose, all under the
microcontroller internal program.
I agree with all your points against LED's except they are very simple to
use and that's what I need for now.

The displays at the aade.com site are very elegant.
If you or someone can recommend which LCD display to use and a site wich a
good tutorial then that would be fantastic.

The whole point of homebrewing for me is to learn how these things work and
be able to design and make changes. Otherwise I can buy all the gear on
Ebay but not learn anything.

(Avery Fineman) wrote in


There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary
memory, and optional backlights. They are driven by ASCII coded
character digital byte-parallel input assemblies. PIC and Atmel
based counters can output ASCII according to count plus including
controllable legends for whatever purpose, all under the
microcontroller internal program.
I agree with all your points against LED's except they are very simple to
use and that's what I need for now.

The displays at the aade.com site are very elegant.
If you or someone can recommend which LCD display to use and a site wich a
good tutorial then that would be fantastic.

The whole point of homebrewing for me is to learn how these things work and
be able to design and make changes. Otherwise I can buy all the gear on
Ebay but not learn anything.

In article , SWbeginner
writes:

(Avery Fineman) wrote in

There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary
memory, and optional backlights. They are driven by ASCII coded
character digital byte-parallel input assemblies. PIC and Atmel
based counters can output ASCII according to count plus including
controllable legends for whatever purpose, all under the
microcontroller internal program.

I agree with all your points against LED's except they are very simple to
use and that's what I need for now.

Then you can go with LS TTL and use a pair of ICs per decade/digit.
A 74LS192 as a decade's actual counter with a CD4511 as a latch-
decoder-driver for the LED...or a CD40110B as a counter-latch-
decoder-driver at a slower input rate (with prescaler as needed to
reach the desired max. input rate). 74LS90s or 74LS290s as decade
dividers for the timebase...plus various NAND gates to select the
count gate times. All of those types figure in to drive LED 7-segment
numeric displays.

The displays at the aade.com site are very elegant.
If you or someone can recommend which LCD display to use and a site wich a
good tutorial then that would be fantastic.

There's over 50 different models and sizes of LCD display assemblies
available, from 1 line of 12 characters to 4 lines of 16 characters. To
use those assemblies, you need to know how to get the sequential
ASCII into them to show on the screen. That isn't simple for a tutorial
or anything else unless you know serial digital transmission basics.
AADE apparently gets their LCD assemblies in bulk to package with
their little frequency counters, have the necessary coupling from the
16F71 program coding.

The bare LCD unit needs special driver ICs since those are generally
of a sort of 3-state waveform needed to clear/energize (make black)
a selected place. Some are only 2-state. Varies depending on the
type and manufacturer. That's why I recommend getting an assembly
of the display and its driver board. A search of the Internet will turn
up several distributors selling to individuals. If the end applicaion is a
counter using a PIC or Atmel microcontroller, then the project website
will have the part number of the display assembly they used.

The whole point of homebrewing for me is to learn how these things work and
be able to design and make changes. Otherwise I can buy all the gear on
Ebay but not learn anything.

Understood. I'm still putting things together and still learning, still
having
fun with all these new things even though I've been in the electronics and
radio racket for quite a while (over 50 years).

You can get the basics of frequency and period counting from the Agilent
website from one of their application notes. There's several other sites
by individuals explaining basic counting. To make an IC counter using
two ICs per decade, a latch-decoder-driver is needed to hold the binary-
coded-decimal 4-bit state out of the counter after a count and then
decode that BCD to light the appropriate LED segment of a 7-bar segment
single digit display. The whole thing needs a timebase section which
is a crystal oscillator (usally at 10 MHz to beat against WWV for
calibration) followed by dividers (usually decade counter ICs running
continuously. The selectable timebase signals are used to gate the
counter's input for frequency indication with the gate opening time in
increments of 10 such as 1, 10, 100 mS, 1 or 10 Seconds for minimum
count digit display of 1 KHz, 100, 10, 1, and 0.1 Hz respectively. To
mesaure period, just reverse the count input and timebase gate control
so that you count the timebase frequency with the gate supplied by the
input signal.

To connect this to the outside world, you need a wideband amplifier to
help raise the level of the input signal, then a shaper such as a Schmitt
trigger gate or inverter to make the signal have nice, sharp leading edges
to apply to the count gate. With all that digital stuff there needs be
attention paid to bypassing the supply rails, but that is easier since all
the components can be running at the same + supply voltage; +5 VDC
if "74" chips, +9 or +12 or +15 if CMOS equivalent function types to TTL.

There are still lots of digital ICs available for this kind of project and
the
datasheets are all downloadable from the Internet. Putting them all
together is not an easy task but it is repetitious to the degree of the
number of digits to be displayed. The number of digits to be shown will
put a rather surprising large current demand on the supply for a maximum
digit indication, "8" in case of a 7-bar LED, all 7 segments on. 140 mA
per decade at 20 mA per segment. With 6 digits that is 840 mA max.
LED supply drain can go from 240 mA min. for all "1" to 840 mA max. for
"8" with 6 digits...can be fair jump in load change on the internal supply.

In going for a discrete IC per decade style, the overall task is a strenuous
one. To begin, it is much easier to get a KIT if possible, or one of the
little AADE counters (which have some user interconnects necessary).
Once you have it built or installed, you have a "learning" device and can
go back into its guts to find out how it works. For PIC or Atmel based
counters, most "learning" takes place in following the program source
code; the hardware itself is rather simple, just a handful of parts.

A frequency (and period if desired) is the most precision instrument you
can successfully design and build in the home workshop. Only one
circuit, the crystal oscillator, sets the accuracy, typically better than
10 parts per million beat against WWV. The rest is enabled by digital
ICs off-the-shelf at relatively low cost (less than $1 each, average). It
does embrace a number of electronics technologies not necessarily
those of old radio. "Simple" it isn't and that includes the micro-
controller types; those have most digital hardware functions
implemented in software. Experience in designing, building, and
working with them will come in handy on such future projects as PLL
or DDS frequency control, DSP, and many other subsystems of
modern radios. If you bother to study them in detail you WILL learn
a lot of new things, but there is considerable "home work" in that self-
assignment. Good luck and enjoy the course! :-)

Len Anderson
retired (from regular hours) electronic engineer person

In article , SWbeginner
writes:

(Avery Fineman) wrote in

There are several LCD display units available commercially with the
LCD (typically 2 x 16 character rows), drivers and temporary
memory, and optional backlights. They are driven by ASCII coded
character digital byte-parallel input assemblies. PIC and Atmel
based counters can output ASCII according to count plus including
controllable legends for whatever purpose, all under the
microcontroller internal program.

I agree with all your points against LED's except they are very simple to
use and that's what I need for now.

Then you can go with LS TTL and use a pair of ICs per decade/digit.
A 74LS192 as a decade's actual counter with a CD4511 as a latch-
decoder-driver for the LED...or a CD40110B as a counter-latch-
decoder-driver at a slower input rate (with prescaler as needed to
reach the desired max. input rate). 74LS90s or 74LS290s as decade
dividers for the timebase...plus various NAND gates to select the
count gate times. All of those types figure in to drive LED 7-segment
numeric displays.

The displays at the aade.com site are very elegant.
If you or someone can recommend which LCD display to use and a site wich a
good tutorial then that would be fantastic.

There's over 50 different models and sizes of LCD display assemblies
available, from 1 line of 12 characters to 4 lines of 16 characters. To
use those assemblies, you need to know how to get the sequential
ASCII into them to show on the screen. That isn't simple for a tutorial
or anything else unless you know serial digital transmission basics.
AADE apparently gets their LCD assemblies in bulk to package with
their little frequency counters, have the necessary coupling from the
16F71 program coding.

The bare LCD unit needs special driver ICs since those are generally
of a sort of 3-state waveform needed to clear/energize (make black)
a selected place. Some are only 2-state. Varies depending on the
type and manufacturer. That's why I recommend getting an assembly
of the display and its driver board. A search of the Internet will turn
up several distributors selling to individuals. If the end applicaion is a
counter using a PIC or Atmel microcontroller, then the project website
will have the part number of the display assembly they used.

The whole point of homebrewing for me is to learn how these things work and
be able to design and make changes. Otherwise I can buy all the gear on
Ebay but not learn anything.

Understood. I'm still putting things together and still learning, still
having
fun with all these new things even though I've been in the electronics and
radio racket for quite a while (over 50 years).

You can get the basics of frequency and period counting from the Agilent
website from one of their application notes. There's several other sites
by individuals explaining basic counting. To make an IC counter using
two ICs per decade, a latch-decoder-driver is needed to hold the binary-
coded-decimal 4-bit state out of the counter after a count and then
decode that BCD to light the appropriate LED segment of a 7-bar segment
single digit display. The whole thing needs a timebase section which
is a crystal oscillator (usally at 10 MHz to beat against WWV for
calibration) followed by dividers (usually decade counter ICs running
continuously. The selectable timebase signals are used to gate the
counter's input for frequency indication with the gate opening time in
increments of 10 such as 1, 10, 100 mS, 1 or 10 Seconds for minimum
count digit display of 1 KHz, 100, 10, 1, and 0.1 Hz respectively. To
mesaure period, just reverse the count input and timebase gate control
so that you count the timebase frequency with the gate supplied by the
input signal.

To connect this to the outside world, you need a wideband amplifier to
help raise the level of the input signal, then a shaper such as a Schmitt
trigger gate or inverter to make the signal have nice, sharp leading edges
to apply to the count gate. With all that digital stuff there needs be
attention paid to bypassing the supply rails, but that is easier since all
the components can be running at the same + supply voltage; +5 VDC
if "74" chips, +9 or +12 or +15 if CMOS equivalent function types to TTL.

There are still lots of digital ICs available for this kind of project and
the
datasheets are all downloadable from the Internet. Putting them all
together is not an easy task but it is repetitious to the degree of the
number of digits to be displayed. The number of digits to be shown will
put a rather surprising large current demand on the supply for a maximum
digit indication, "8" in case of a 7-bar LED, all 7 segments on. 140 mA
per decade at 20 mA per segment. With 6 digits that is 840 mA max.
LED supply drain can go from 240 mA min. for all "1" to 840 mA max. for
"8" with 6 digits...can be fair jump in load change on the internal supply.

In going for a discrete IC per decade style, the overall task is a strenuous
one. To begin, it is much easier to get a KIT if possible, or one of the
little AADE counters (which have some user interconnects necessary).
Once you have it built or installed, you have a "learning" device and can
go back into its guts to find out how it works. For PIC or Atmel based
counters, most "learning" takes place in following the program source
code; the hardware itself is rather simple, just a handful of parts.

A frequency (and period if desired) is the most precision instrument you
can successfully design and build in the home workshop. Only one
circuit, the crystal oscillator, sets the accuracy, typically better than
10 parts per million beat against WWV. The rest is enabled by digital
ICs off-the-shelf at relatively low cost (less than $1 each, average). It
does embrace a number of electronics technologies not necessarily
those of old radio. "Simple" it isn't and that includes the micro-
controller types; those have most digital hardware functions
implemented in software. Experience in designing, building, and
working with them will come in handy on such future projects as PLL
or DDS frequency control, DSP, and many other subsystems of
modern radios. If you bother to study them in detail you WILL learn
a lot of new things, but there is considerable "home work" in that self-
assignment. Good luck and enjoy the course! :-)

Len Anderson
retired (from regular hours) electronic engineer person

I started with VK3BHR's very inexpensive, easy to build one:

http://ironbark.bendigo.latrobe.edu.au/%7Erice/

I am sure Phil would email you a version of the software that displays your
own callsign at startup.

VK3UBN

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

I am looking to build a frequency counter, or buy an inxepensive kit.
Any recommendations?
Needs: low cost, few parts count

Recommendations depend on your intended function.

The general-purpose counter from Almost All Digital Electronics is
good, ready-built with LCD for about $40 (give or take depending on
optional backlight or BIG - actually slightly bigger - LCD, temp.
compensated timebase oscillator, etc.). Try examining
www.aade.com. A good Puget Sound area little company.

A "very low parts count" of one would be the CSI 6100 general
purpose counter from Circuit Specialists, Inc., for $129 ready to
use on either 115 or 230 VAC lines. I have one of those very
no-frills units and it works (just got it as a backup on the bench).
I've seen better displays than this one has but I can't fault the
price for a complete unit ready-to-go.

To roll your own counter-timer-etc., the Intersil ICM7216B 28-pin
DIP will count to 10 MHz by itself and drive up to 8 LEDs, has an
on-board timebase oscillator and function switching internal. The
datasheet has several schematics, fairly complete, for making
your own. Add a divide-by-10 or divide-by-100 digital prescaler
and the input frequency range can extend to 100 or 1000 MHz.
The only problem with that is that Intersil is going to OBSOLETE
the critter and is apparently out of production (unless you have a
very large quantity to order, like many thousands).

The Intersil ICM7226B is, or was, a fancier version of 7216, having
a 40-pin DIP. It seems to be all gone except on paper. Some
distributors may still have some 7216s around in stock. I have
datasheets for both and can forward them in e-mail attachments.

Several websites have nice pages on using the Microchip PIC
16F84 or 16F71 (AADE uses the '71) as a complete counter and
display driver for an LCD, extra transistor things for LEDs, using
only 3 ICs total (plus a prescaler to go higher than about 35 MHz
maximum with the PIC). That arrangement is nice because one
can program in "offsets" of the count such as reading a local
oscillator directly, then adding/subtracting the IF to get the antenna
input frequency. The only problem there with rolling your own is
that, while the PIC development software is free, and program
boards are low cost, if you aren't used to Assembler-like language
and coding at the machine level, you have a large learning curve
to climb. That may be worth it since microcontrollers are VERY
versatile, can do amazing things with some creativity, even put
ASCII legends of all kinds on the LCD screen besides the basic
functions of totalizing a count. PICs of many numbers abound at
distributors such as Digikey and Mouser.

To use lots of ICs of the "74" family, two to three per digit plus the
timebase divider, would be the last alternative. The 74LS190 to
74F190 series is still around but the BCD versions are getting
scarce; binary versions (count of 16) are there but the decade ones
are apparently being dropped for new production. 74LS160 to
74F160 in the same boat. There is even a CD4nnn which has a
whole BCD counter, 4-bit latch, 7-segment decoder-driver in a single
DIP that will work up to about 4 MHz, higher with an input prescaler
(I have to search my PDFs for the exact number).

The IC makers have been winnowing their available types over the
last decade, tightening their belts, dropping some things that did
not sell well (despite their usefulness to hobbyists), adding new
things and getting into the SMT area with a rush that started in the
late 1980s. Expect more type dropouts. Adapt, improvise... :-)

Len Anderson
retired (from regular hours) electronic engineer person