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]
This page describe how to build radiation detector and how to interface it with a USB capable microcontroler to connect a PC. The geiger counter is a pretty simple device to detect radiations. Many forms of radiations from radio elements (alpha, beta, gamma) can be detected but it is more sensitive to beta and gamma radiations. The Geiger-Muller tube is a simple device, it’s a tube filled with a gas with two electrodes. A high potential is applied betweens electrodes. When a ionizing particle arrived, it create a temporary conductive path between electrodes. The resulting current can be detected by an electronic amplifier.
How to build a geiger counter with USB interface – [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]
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]
Frequency counters are very popular and easy to build projects. This one is a AT90S8515 microcontroller and Lattice ispLSI2032 PLD based frequency counter. While microcontroller mainly takes care of communicating and data display, PLD counts incoming pulses and scales them down because of hardware 36bit counter implemented. When counter counts up – it generates an interrupt for MCU.
Frequency counter also has ability to communicate with PC via serial port. This way counter can log data to computer or be simply controlled by computer. Project files and source codes are available for download in project page. [via]
Universal frequency counter – [Link]
Remember the Electronic Hits Counter i wrote about last week ? There’s a new version out, this time Bob made the counter USB capable, this means you connect it to your pc trough USB instead of RS232. The functionality is still the same, it shows your website hits, on a LED display which is cool. I’m gonna build one soon. [via]
Electronic Hits Counter > USB version – [Link]
Jesper writes: This is another project which fullfills a need. I once built a frequency counter using plain TTL chips. That was long before the CMOS HC versions, even before LS was available. It could measure up to 50 MHz and worked quite okay, but the TTL chips was extremely power hungry. I think there was about 20-25 TTL chips on that monster. Well, but the old counter is now somewhere in the shed, and as I now again needed a counter, I did a bit more modern design.
It uses only 4 chips – 3 HC TTL’s and an Atmel At90S2313 microcontroller. It has a 5 digit LED display plus one used as a band indicator. Even with the LED display, the current consumption is less than 50 mA. It counts up to at least 52 MHz. I couldn’t find any signal source in the lab that could supply more than 52 MHz, so it may go a bit higher, but the fClock(typ) for the HC590 is about 35-40 MHz, so you shouldn’t really count (no pun intended) on more. [via]
AT90S2313 Based Frequency Counter – [Link]