Digital frequency counter extensively uses digital circuits and hence fairly good knowledge of digital circuits and of digital integrated circuits is required to understand the operation of the frequency counter. However a person who is not familiar with any electronics circuits and experiments has in written this article.
Simple Frequency Meter - This circuit is a frequency meter, i. The main component of this circuit is thea versatile, general-purpose timer IC. In this circuit, the is configured as a monostable multivibrator that outputs a single pulse at pin 3 every time the input signal at pin 2 goes 'low'. In timer mode maximum resolution is 0.
Resolution is reduced by one digit for each additional decade. Multiple frequency updates per second by employing a sliding window for calculation. By adding couple of transistors and operation amplifier TL, it is possible to lock the LC oscillator frequency. Software functions are presented inside the dashed area. The range is 0 - 30MHz with an input sensitivity of greater then mV.
The probe connects to the PC serial port. So by using the crystal oscillator already present on your PC serial card and software calibration, the Probes' external circuitry is kept to a minimum.
Frequency Counter Circuit
The IC1 Schmitt trigger that it regulates the signal of entry and him changes in reasonable level suitable for the IC Exclusive 2. You have also two level of resolutions, 1kHz and Hz. The main oscillator can be on-board 13MHz or external 10 MHz. The counter data can easy be transmitted to computer with RS cable. The construction is extremely simple and the unit is very small. Range to the Minimum Mass Base Unit is 10 to 15 cm. Since the frequency meter is battery operated, it can be floated from ground, making life in and around the test bench a lot simpler.
No need to connect it to the computer or LCD display - just turn in on and place it next to the base unit.Have you ever needed to find out how quickly something is oscillating? For things like hamster wheels and ocean waves, this is easy.
You just count how many times the wheel goes around in a certain amount of time, then do some math, and you have the frequency. But what if you're dealing with something a little less tangible like audio waves or electronic signals?
That's where digital electronics saves the day. This Instructable will show you how to build a digital frequency counter capable of measuring events up to kHz and will attempt to explain some of the electronics theory behind it. This is actually my term project in a Digital Electronics course at the University of Oregon. It's intended as an addition to my term project from the winter term, which was a Function Generator I also posted to this site. Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson. A frequency counter is a device that measures a periodic signal and determines its frequency in Hertz Hz or s But how does it do it? If you were trying to determine the frequency of a wheel manually, you might follow this operation: 1.
How to compute the frequency of a clock
Mark a spot on the wheel, then let it spin. Start a timer. Count how many times the spot on the wheel reaches the top. Stop the timer. Divide the number of rotations by the amount of time that passed while you were counting. The result of the division would be the frequency of rotation of the wheel. This build actually follows the same steps, but it does all the operations automatically, repetitively, and it doesn't actually do any math.
The math is built into the way the frequency counter counts. This frequency counter actually follows these steps: 1. Generate a stable, known, reference time period. Count the number of periods of the signal you're measuring. At the end of the reference time period, display the number of counts and reset the count to zero. These steps can be completed very quickly and repetitively using digital electronics methods.
It's a very "dumb" process. The accuracy of the output frequency depends wholly on the accuracy of the reference time period and the speed of the counting chips. Using quartz crystal oscillators, we can generate reference periods with an error of about 20ppm, or 0.
Digital electronics can typically handle up to 30MHz signals, so this project is actually quite accurate. The key to keeping any math out of the device is to make the reference periods base ten decimal. Digital electronics is all base two binary so we need some chips that let us do some decimal conversion. What would be really nice is to just have a 1 second reference period. Then we could just count the number of pulses from the measurement in one second and display that and we'd automatically have Hz.
That's actually what's going on. But there are only three digits for display.
How do we keep the display from rolling over?In this project, I will design and demonstrate a simple Frequency Counter Circuit, which can be used to measure the frequency of a signal. This project is based on Microcontroller, although you can design a non-microcontroller version. A frequency counter is an instrument that is used to measure the frequency of a signal. In scientific terms, frequency is the number of cycles per second of a signal.
In layman terms, frequency of a signal denotes the rate of occurrence of the signal in certain time. Frequency Counters are basically simple counter systems with a limited time period for counting.
Here we design a simple frequency counter system using two timers and two counters. While one of the Timer IC is used to produce clock signals, the other is used to produce the time limited signal of one second. This circuit is based on the simple definition of frequency, which is the number of cycles per second.
Basically, a Square Wave Generator circuit is used to produce a simple pulse wave. But if you are planning to build a Square Wave Generator circuit using Timer IC, the understand the following explanation.
Since duty cycle depends only on the value of the threshold and discharge resistors, it can be adjusted by selecting the proper values of resistors.
Substituting the value of D to be 0. Next step in the designing of the circuit is the design of the counter circuit. Here our requirement is the measurement of frequency of the order of few Kilo Hertz.
In fact, I will be using both Timer 0 and Timer 1 of the Microcontroller. I will be using Timer 0 to generate Time Delay and Timer 1 to count the Pulses coming from the pulse generator. Following is the code for Frequency Counter Circuit using Microcontroller. Make the connections as per the circuit diagram and apply the Pulse generated by Arduino at Port 3 Pin P3.
The count of the pulses is stored in Timer 1 i. To get the value of the frequency, you have to use the following formula. In order to convert the Frequency Value to Hertz i. Cycles per Second, you need to multiply the resultant value by After this, the resultant value is formatted by performing some simple mathematics so that it will be easy to display the result on the 16X2 LCD Display.
I need all the requirements for the frequency counter circuit of this diagram which is given above. It will be helpful for me if you do this please send me on rs. Your email address will not be published. Table of Contents. Comments how to work in electonice component. I need some help. Leave a Reply Cancel reply Your email address will not be published.Almost every electronic hobbyist must have faced a scenario where he or she must measure the frequency of signal generated by a clock or a counter or a timer.
We can use oscilloscope to do the job, but not all of us can afford an oscilloscope. We can buy equipment for measuring the frequency but all these devices are costly and are not for everyone. With that in mind we are going to design a simple yet efficient Frequency Counter using Arduino Uno and Schmitt trigger gate. To test the Frequency Meter, we are going to make a dummy signal generator.
This dummy signal generator will be made by using a timer chip. The timer circuit generates a square wave which will be provided to UNO for testing. With everything in place we will have a Frequency meter and a square wave generator. The circuit diagram of the Frequency Meter using Arduino is shown in below figure.
Circuit is simple, a LCD is interfaced with Arduino to display the measured frequency of signal. For filtering the noise we have added couple of capacitors across power. This Frequency Meter can measure frequencies up to 1 MHz.
First of all we will talk about IC based square wave generator, or should I say Astable Multivibrator. This circuit is necessary because, with the Frequency Meter in place we must have a signal whose frequency is known to us. Without that signal we will never be able to tell the working of Frequency Meter.
If we have a square have of known frequency we can use that signal to test the UNO meter and we can tweak it for adjustments for accuracy, in case of any deviations. Typical circuit of in Astable mode is given below, from which we have derived the above given Signal Generator Circuit. The equation is given as. By putting the resistance and capacitance values in above equation we get the frequency of output square wave.
One can see that RB of above diagram is replaced by a pot in the Signal Generator Circuit; this is done so that we can get variable frequency square wave at the output for better testing. For simplicity, one can replace the pot with a simple resistor.
We know that all the testing signals are not square or rectangular waves. We have triangular waves, tooth waves, sine waves and so on.
With the UNO being able to detect only the square or rectangular waves, we need a device which could alter any signals to rectangular waves, thus we use Schmitt Trigger Gate. Schmitt trigger gate is a digital logic gate, designed for arithmetic and logical operations.This document describes the construction of small frequency counter with a cheap PIC microcontroller and a few seven-segment LED digits.
The main features of the frequency counter are: frequency range 1 Hz Please do not ask me to send programmed PICs or even circuit boards to you, my spare time is too short - and you will find anything you need on these "do-it-yourself" pages! If your counter shows a strange frequency initially, enter setup mode to set the frequency offset to zero it sometimes happens that PIC programmers don't erase the EEPROM where the frequency offset is stored.
Construction - Variant 1 The first prototype with very old, low-efficiency 7-segment displays looked like this: PIC frequency counter prototype, connected to a grid dipper A flashing decimal point indicates a frequency in kilohertz, a steady point indicates a frequency in Megahertz - which is more common for the intended use in dip meters and QRP transceivers.
The first prototype was built on a breadboard with round pads. A very similar design could be used for a single-sided printed circuit board. Note that the crystal is mounted on the bottom side! Some of the display signal are routed with thin enamelled copper wire, especially those between two pads.
Use firmware "counter1. R11 set the brightness and the power consumption. If you find some suitable low-current displays, use 1 kOhm or even more. Very old displays require more current, use Ohms in that case. The PIC's output ports can source and sink 20 mA per pin, so the digit drivers are a slightly overloaded with Ohm resistors per segment when displaying "8. If you don't have to care for power consumption and want to use old displays with high current, use four PNP! For the displays "SCSRWA" by Kingbright it is unnecessary to use driver transistors, these high-efficiency displaye are bright enough with 1 kOhm current limiting resistor per segment.
You will be disappointed by a dark display, at least with the resistor values stated above. Beware, other distributors of electronic components like C. Construction - Variant 2 For the second prototype, a 5-digit display was made on a single layer PCB shown below. To make connection between PIC and display board easier, a second firmware variant was created with slightly modified pin assignment. On this occasion, the PIC's clock frequency was increased to 20 MHz to have a better resolution at higher frequencies.
Layout of the PIC board display variant 2. The board contains the decoder for the 5th digit, and some breadboard area for the preamplifier if needed. Print this image with exactly dpi, which can be achieved with IrfanView and other utilities. The display is mounted on the lower side of the PIC board as shown below. The square pads near the display are the cathode connectors from left to right: d Placement of the components on the PIC board Ridiculously simple, isn't it?
But don't forget to place the bridge under the PIC socket before soldering! Here is one suggestion for a layout for the display board display variant 2, also print this with exactly dpi : This board is quite universal, I plan to use it for a PIC-based DDS generator too. For the frequency counter, the connector pads "g","a","f","b" are not used because these four resistors RLatest Projects Education.
Search Forums New Posts. I am not too much into microprocessor interface so if anyone can help me it will be great. Scroll to continue with content. What does your circuit look like so far? Post your diagram here. Maybe we can guide you through the rest of the design. IBQ102 2.6GHz Frequency Counter - Review, Teardown, Experiments
Start by reading up on the It's not going to be an easy project with that old microcomputer, it's more a task for a microcontroller.
I already drew this block diagram attached ,but i don't know how to start the assembly code. Frequency Counter Block-Diagram. The block diagram is a good beginning. Don't forget to account for the power supply. Now you can begin to take a stab at designing each of the blocks you have indicated in your diagram. When's it due? It's a really poor choice for a frequency counter project.
It's pretty simple to make one with a timebase, some logic, and some counters. School projects are supposed to be instructive, though. Too bad it's a stinky instead of a or a You must log in or register to reply here.
Similar threads Frequency Counter Very Wide input voltage circuit for frequency counter? Sound Frequency counter design frequency counter design.A frequency counter measures the frequency of an input signal.
These are commonly used in laboratories, factories and field environments to provide direct frequency measurements of various devices. Most frequency counters work by using a counter that accumulates the number of events oscillations occurring with in a specific period of time say, one second.
After the preset time period, the value in the counter is transferred to a display and the counter is reset to zero. Five decade counter- cumsegment-driver ICs each CD are connected in tandem to form a 5-digit decimal counter. IC CD consists of a 5-stage counter and an output decoder that converts the code into a 7-segment decoded output for driving one stage of a numerical display. The sinewave signals coming from the oscillator source are first converted into positive-going pulses with the help of transistor T2 and diode D1.
These pulses are then counted by the 5-digit decimal counter. The NE is a highly stable controller capable of producing accurate timing pulses. The time period of the monostable multivibrator is determined by the combination of resistor R5, preset VR1 and capacitor C4.
Here it is set precisely to one second. The time period of the astable multivibrator is determined by the combination of resistors R1 and R2 and capacitor C1. The monostable multivibrator IC2 is triggered whenever the output of the astable multivibrator IC1 goes low.
The output of IC2 instantly goes high and remains high for one second. As soon as IC2 is triggered, the leading edge of the positive-going output pulse sends resting signal to all the decade counters via capacitor C6. It continues counting the input pulses as long as the output of IC2 remains high. After one second, the output of IC2 becomes low again.
The process repeats, as long as power is applied to the counter circuit. Pin 5 of timer NE is the control voltage pin that is primarily used for filtering when the timer is used in noisy environments.
However, by imposing a voltage at this pin, it is possible to vary the calculated period.