The device presented here can be used to count events as well as to measure frequencies and times. Most of it is built from discrete HC (high speed CMOS) logic and to be honest, if I needed to build such a device again, I would not build it as presented here but integrate things into a CPLD or a microcontroller instead. However, it was instructive not to do so and maybe it is interesting for other people as well (for what reason ever).
- Frequency measurement from 0.1Hz to ≥10MHz; gate times of 0.1, 1 and 10 seconds
- Time measurement 0.001ms to 10000s (time clock 1MHz and 1kHz): measuring L/H time or 1, 10 or 100 complete pulses or time between input A and B transition
- 5-digit LED display with display hold
- CMOS-compatible Schmitt-trigger inputs with over- and under-voltage protection
Frequency Counter - [Link]
This project will turn your multimeter into a sensitive frequency counter with a wide counting range. You can also use this project to upgrade your old frequency counter and extend the range up to 2.5GHz. This project will describe a prescaler which will work up to 2.5GHz and with very high input sensitivity. The prescaler will divide the input frequency with either 1000 or 10.000.
Poor man’s counter - [Link]
This simple design uses the 20 pin ATTiny2313 microcontroller to measure frequencies from 1Hz to over 2MHz. The frequency is displayed on a standard HD44780 16×2 LCD. A bright white text, blue backlit LCD is included with the kit. The device requires a regulated 5V power supply. [via]
FunCount Frequency Counter – [Link]
On cloud busters Fredbuster created a wonder tutorial for getting started and building your own Zapper. Fredbusters Tutorial in PDF-Based off his design here is how I made my frequency generator. [via]
How to make a Frequency Generator - [Link]
This article shows how to build a small, cheap and simple frequency meter, without any fancy, out of reach components. The simple proposed design can measure frequencies up to 40 Mhz with errors below 1%! This degree of precision will be more than enough to debug most of your analog and digital circuits, and will give you the ability to analyze many aspects that you were unable to see before.
Build your 40 MHz Frequency meter! - [Link]
This is the Frequency Counter for 100Hz-2.5GHz, using LCD 16 chara.x 2 lines ,TCXO 12.8MHz(1ppm ) and PIC16F84. The Voltage (0-510mV) of the input signal is also indicated on the LCD , therefore tuning of the coil can be conducted while checking the frequency. Furnished with IF offset-function, this can be applied for the frequncr display of the home brewed transeiver. Print circuit board size is very small of 100mm x 43mm. [via]
Frequency Counter – [Link]
Frequency counter built by Wayne McFee. This is from IK3OIL’s web site, and the cost of the counter was about $2, minus the display, which was about $7. Design and Code by Francisco IK3OIL. McFee writes:
This frequency counter was mentioned on the QRP-L mailing list. I offered to put up some more information on the counter on this web page. I have not built one (yet) nor do I have any further information than what is here.
16F84 PIC Frequency Counter - [Link]
This project came about because of a need to accurately calibrate the piles of HP test equipment I have been buying off ebay. This project uses a 10mhz voltage tuned crystal oscillator whose frequency is locked to the GPS positioning system clock. The GPS I used was a Canadian Marconi (CMC) Superstar single board OEM GPS receiver with a Motorola external amplified GPS antenna. The ovenized crystal oscillator is a modified Anritsu MH4100A standard crystal oscillator. [via]
GPS Locked 10Mhz Frequency Reference - [Link]
An AVR controller can be used as a counter, although it is a bit more involved than with a PIC. The reason is that a PIC (at least the 16F84) has an asynchronous counter input. This input will handle frequencies up to app. 40 MHz. AVR’s have a synchronous counter input which is sampled with the clock frequency, so it cannot measure frequencies over half the clock frequency. So, when using a 4 MHz clock, input frequencies must be lower than 2 MHz. Use 40% of the clock frequency to be on the safe side. [via]
A 2.5 GHz frequency counter - [Link]
This basically the frequency meter section of the frequency meter/pulse generator based on the AT90S2313 described elsewhere on this site, combined with the 100 MHz RF interface described in the page about the RS-232 to 100 MHz RF desktop channel adapter. Built and align this is the same manner as the 100 MHz RF desktop channel adapter. The frequency meter has a maximum input frequency of 4 Mhz and counts up to 65535. Time bases of 10 ms, 100 ms, 1 second, 10 seconds, and 100 seconds are selectable from the keyboard via the RF link. [via]
Frequency Meter with 100 MHz RF desktop channel - [Link]