Searching \ for ' Weeder Frequency Counter' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/timers.htm?key=count
Search entire site for: 'Weeder Frequency Counter'.

No exact or substring matches. trying for part
PICList Thread
'Terry Weeder Frequency Counter'
1998\10\15@234224 by WIL REEDER

flavicon
face
Hi,

Yes I have one of Weeder's counter kits. It was $46. USD plus pp. It is
very accurate as long as the pic clock is trimmed properly. The circuit
board is nicely made and all the parts fit properly, dead simple to build.
This kit has a very effective front end amplifier using a fet, for those of
you that were looking for a preamp a few days ago.
I did not check the current draw but mine has been operating for several
months from a rechargeable 9v (8.4) transistor radio type battery; without
recharging!
The only wart I could complain about is the LCD has a very narrow viewing
angle and sometimes I have to prop the thing up on something to be able to
read it. This is a very small problem and I am happy with this counter. I
could not source the parts for less money than the kit, excellent value!
Terry is in Florida 850-863-5723 I tried his website but he has moved,
maybe a search would track down his new url.

Good luck


Wil Reeder
Vancouver, Canada
spam_OUTteachtechTakeThisOuTspambc.sympatico.ca


'[PICLIST] Weeder Frequency Counter'
2002\02\11@121506 by Ted Mawson
flavicon
face
I've been looking at the Weeder Frequency counter on the PIClist archives.  I called Weeder today and they no longer do the kit or any part of it.

Questions:

1.    Is there anywhere else that has the kit in stock or even just the PCB?
2.    It looks like the original ran on a 4MHz crystal; if we used a 20MHz clock, couldn't we increase the max frequency capability?  Has anyone done this already?

Thanks,

Ted
.....PICmanKILLspamspam@spam@portfoliopm.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\11@124234 by Peter Onion

flavicon
face
On 11-Feb-02 Ted Mawson wrote:
> I've been looking at the Weeder Frequency counter on the PIClist archives.  I
> called Weeder today and they no longer do the kit or any part of it.

Its 16F84 based so its got a "near obsolete" PIC in it :-)

I would use a 16F62X  which has a 16bit Timer1 in it and you need much less
external hardware (IE you don't need the 74HC132).

The circuit is quite simple so I'm sure you could build it on a bit of
vero-board without any problems.

Peter Onion.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\11@124901 by Peter Onion

flavicon
face
On 11-Feb-02 Ted Mawson wrote:
> I've been looking at the Weeder Frequency counter on the PIClist archives.  I
> called Weeder today and they no longer do the kit or any part of it.
>
> Questions:
>
> 1.    Is there anywhere else that has the kit in stock or even just the PCB?
> 2.    It looks like the original ran on a 4MHz crystal; if we used a 20MHz
> clock, couldn't we increase the max frequency capability?  Has anyone done
> this already?

OPSE didn't answer this question.

The PIC clock rate does NOT determine the maximum frequency that can be
measured.  The input signal is used to drive a hardware counter in the PIC.
A higher PIC clock won't actually give you any advantage in either the range or
the accuracy of the displayed frequency....

Hmmmmmm,...... Thinking about it.... A higher PIC clock MAY give better
accuracy as the jitter in interrupt latency will be reduced.  I run my 16F877
freq counter from a 14.7something Mhz crystal to get an accurate 0.1s timebase
using the maximum count (256) in Timer0.

I posted some code here a few weeks ago that may help you if you decide to
D-I-Y.

Peter Onion.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\12@033720 by Russell McMahon

picon face
> I've been looking at the Weeder Frequency counter on the PIClist archives.
I called Weeder today and they no longer do the kit or any part of it.  2.
It looks like the original ran on a 4MHz crystal;

           >if we used a 20MHz clock, couldn't we increase the max
frequency capability?

Careful - within reason the achievable maximum speed is set by the maximum
toggle rate of the prescaler/divider. This is a hardware spec which is
essentially inependent of cpu clock speed capability. AFAIR, in some earlier
processors LOWER spec CPUs were capable of higher prescaler clocking rates.

AFAIR the original 16C54's used for this application were capable of 50 MHz
while some chips with the enhanced core had a lower max prescaler rate.

A quick look at an arbitrarily old 16F84 data sheet shows a Thi and Tlo with
prescaler input of 30 ns and 20 ns for a max frequency of 20 Mhz if your
input wave was suitably asymmetric or more safely 1 / ( 2 x 30 nS) =~ 16
MHz.





                           Russell McMahon

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...