Well, some of you here might have built a few PIC frequency counter before, and fully understand about its usability in the electronic field. However, for those who never get in touch with PIC frequency counter, it’s an electronic instrument that being used for measuring frequency.

Technically, frequency is defined as the number of events of a particular sort occurring in a set period of time. In order to measure the frequency, you have to use a counter to accumulate the number of events occurring within a specific time. Let’s say, after a preset period (1 minute, for example), the value in the counter is to be reset to zero automatically!

By the way, we’re going to build an IK3OIL 16F84 PIC Frequency Counter. Most people are worry, as they might need to waste a lot of money buying the electronic components. Well, you know what? This IK3OIL 16F84 PIC Frequency Counter is very cheap, as the cost of the counter is cost you about US$2, while the display is only less than US$5!

Frankly, this IK3OIL 16F84 PIC Frequency Counter is a marvelous frequency counter, as it not only cheap, but can perform a better result than other frequency counter did!

Breadboard, it either can be solderless breadboard, protoboard or plugboard is a very reusable solderless device. It’s always being used to build a prototype of an electronic circuit. Many electronic systems normally have been prototyped by using breadboard, from small analog and digital circuits to complete central processing units.

Speaking of breadboard, the project that you’re about to develop here is the PRO-I/O breadboard development system. For your information, the main purpose of this device is to emulate various input and output devices in nowadays designs. Those important components that include into the device are:

• Switches,
• Pushbuttons,
• A 2×16 character LCD display,
• LEDs
• Small serial terminal,
• A frequency generator,
• A frequency counter, and
• Two voltmeters.

The PRO-I/O is built based on an Atmel ATmega16 microcontroller and the whole design can be easily fitted into a small case. It uses a 40-pin keyed cable to connect to the target breadboard. The cable is equipped with all the input and output signals for the target interface.

By the way, you also need to include a USB interface into the project instead of an RS232 serial connection. It is because the USB port can obtain power from the PC much quicker than RS232 serial connection did.

Lastly, don’t forget to plug in the AC adapter and test its performance, once you’re done with it!

How often you get involved with the frequency counter? Do you know that the frequency counter is designed for radio frequencies (RF) are common and operate on the same principles as lower frequency counters did?

Normally, they have more range before they overflow and for very high frequencies, many designs are use a high-speed prescaler to bring the signal frequency down to a point, where normal digital circuitry can be operated.

The frequency counter that you’re about to build here is a basic and low cost frequency counter circuit, where it can measure from 16Hz to 100Hz signals with a maximum amplitude of 15V. The sensitivity is very high and the resolution is 0.01Hz. For the input signal, it can be a sine, a square or a triangle waveform!

The accuracy of a frequency counter is strongly dependent on the stability of its time base. Those highly accurate circuits are normally used to generate this for instrumentation purposes, and it is usually using a quartz crystal oscillator within a sealed temperature-controlled chamber known as crystal oven or Oven controlled crystal oscillator.

When the frequency doesn’t need to be known to such a high degree of accuracy, simpler oscillator can be used for the purpose. Furthermore, it is also possible to measure frequency by using the same techniques in software in an embedded system.

Most of you here have at least involved yourself with the frequency counter. However, how well do you know about this electronic component?

The frequency counter is an electronic component that is used for measuring frequency and it’s usually measure the number of oscillations or pulse per second in a repetitive electronic signal.

Most of the frequency counters work by simply using a counter that accumulates the number of events occurring within a specific period of time. After a present period, the value in the counter is transferred to a display and the counter is reset to zero. If the event being measured repeats itself with sufficient stability of frequency and this frequency is considerably lower than the clock oscillator being used, then the resolution of the measurement can be greatly improved by measuring the time required for an entire number of cycles!

Furthermore, the accuracy of a frequency counter is strongly dependent on the stability of its timebase. A highly accurate circuit will be used to generate this for instrumentation purposes, and it’s usually using a quartz crystal oscillator within a sealed temperature-controlled chamber, which it is known as crystal oven or oven controlled crystal oscillator (OCXO).

Do you believe with a measly of $7, and you will get a 16F84 PIC frequency counter?

Well, in fact a counter would only cost you less than $2, while the LCD display will cost you a little bit more, which about $5 each.

Those simple and user friendly features in the 16F84 PIC frequency counter also elaborated the uniqueness of it as well.

There are several sophisticated characteristics in this frequency counter, and you might be having the interest on this project even more. Those features are:

A very cute stand alone frequency counter.

A comprehensive digital readout function, which you can eventually set the IF
offset to any of three combinations i.e.: VFO+IF…. VFO-IF or  IF-VFO with the mode switch.

Turn the frequency counter into a Gig region; with just a simple modification, (The additions will include the pre-scaler).

A typical 14 MHz count will be around this figure: 14.060.45.

Note: Make sure you can mount the frequency counter into a 2N2/20.

It is always a fun experience to build a simple and reasonably cheap frequency counter.