Frequency Counter Design - Page 1
Forum section: electronics / general

author: Clayton
author_rank: Contributor
timestamp: December 14, 2011, 05:26:07 am
content: Hi folks, I am attempting to construct a frequency counter from scratch.I'm going with the ATTiny2313 in a similar config to the onehttp://www.nuxie1.com/guides/funcount-frequency-counter.htmlThis configuration is intended to operate to 2Mhz but I need something that works up to 30mhz (10m on ham band)Placement of a prescaler <should hopefully> solve the problem but I can't seem to locate one. The closest I'm finding is the UPB1509 but this one works from 500mhz up whereas my input will be in the 10s of mhz.Any suggestions?

author: amspire
author_rank: Super Contributor
timestamp: December 14, 2011, 05:46:37 am
content: You might want to take a look at this similar project:http://www.cappels.org/dproj/30MHzfmeter/30MhzFmtr.html

author: ejeffrey
author_rank: Super Contributor
timestamp: December 14, 2011, 08:17:38 am
content: Any ripple counter is a prescaler. A 74AC4040 should do the trick.

author: Clayton
author_rank: Contributor
timestamp: December 14, 2011, 02:05:10 pm
content: Quote from: amspire on December 14, 2011, 05:46:37 amYup! I had initially gone with this design however the output requires a serial interface to drive the lcd. To me this approach seems to require too many components and is not cost effective. Sigh.

author: Clayton
author_rank: Contributor
timestamp: December 14, 2011, 02:06:27 pm
content: Quote from: ejeffrey on December 14, 2011, 08:17:38 amOk, cool; Do you have any resources or guidelines on how this can be implemented?Update: I just looked at the Data sheet. Is it that simple to just send the clock to pin 10 and then select your desired multiple?

author: ejeffrey
author_rank: Super Contributor
timestamp: December 14, 2011, 02:34:24 pm
content: Yes, it is that easy

author: EEVblog
author_rank: Unknown
timestamp: December 14, 2011, 10:19:29 pm
content: I have an old 6 digit design using discrete components:http://alternatezone.com/electronics/freq.htmWorks to about 40MHz or so.Dave.

author: tinhead
author_rank: Super Contributor
timestamp: December 15, 2011, 12:26:37 am
content: Quote from: EEVblog on December 14, 2011, 10:19:29 pmehm, what is the function of IC1B ?

author: joelby
author_rank: Frequent Contributor
timestamp: December 15, 2011, 12:49:33 am
content: A spare/unused half of a chip? With its inputs tied to something convenient and nearby?

author: tinhead
author_rank: Super Contributor
timestamp: December 15, 2011, 12:56:37 am
content: Quote from: joelby on December 15, 2011, 12:49:33 ami know what to do with unused pins, the question was why these counter pins are connected to master reset.Now it looks just like "missing function"/"wire" or "not finalized idea"

author: joelby
author_rank: Frequent Contributor
timestamp: December 15, 2011, 12:57:47 am
content: It could be that they were just the most convenient thing to connect them to, since it's a single-sided board with no handy ground plane.

author: tinhead
author_rank: Super Contributor
timestamp: December 15, 2011, 01:19:31 am
content: Quote from: joelby on December 15, 2011, 12:57:47 amyeah "maybe" - but when you look on the PCB you will find wired thing :CP0 floating; Q0 and CP1 connected together - that's the master reset wireon schematic CP1 and CP0 connected to master reset - Qx floating which is okIn principle MR - pin 14 - could be used to define CP0/CP1 levels, now a "floating counter output" (because CP0 is floating)is routed to master reset. I think the idea was to ground CP0 and wire CP1 to master reset as ground not possiblebecause of crossing master reset wire.

author: EEVblog
author_rank: Unknown
timestamp: December 15, 2011, 01:41:56 am
content: Quote from: joelby on December 15, 2011, 12:57:47 amCorrectamundo.Dave.