Very often when designing some stuff I need a square wave signal generator with variable pulse width and frequency to control power MOSFETS.
You can use such a tool when designing DC-DC converter or switch-mode power supply, you can use it to emulate PWM from microcontroller when developing some new embedded design, or maybe you want to design your own wireless charger… This is only some of the things you can use it for.
PWM Generator Project - [Link]
A long time ago I built a radio using a Philips UV616/6456 TV tuner that is capable of receiving radio signals over a large range of frequencies. It ranges from 47MHz up to 860Mhz which gives me the possibility of decoding either Over-the-Air or Cable TV signals.
The problem is that the radio doesn’t have a frequency display, so tuning a particular frequency is always a challenge.
This project is about building a frequency counter, using a 2×16 LCD and a small PIC 18F1320 micro-controller.
VHF/UHF Basic Frequency Counter - [Link]
Here is my new Frequency meter who was done with a LCD’s cellular phone!!! This is a simple project. The Frequency is passing through an op-amp to convert it in a square wave. The ouput of the op-amp is feeding the 3*8 bits counter (24 bits) who can accumulate at a maximum of 16777216 count.
Frequency Meter – [Link]
To show that iPhone is not just a fashion accessory, as many like to say, read below how to make it a useful device. It is a frequency generator with solid characteristics. Quality will satisfy the needs of amateur electronics and it will be sufficient for the basic measurements and adjustments in audio technology.
iPhone as a frequency generator – [Link]
Embedded-Lab.com has just posted a new project called “Multi-function power supply”. It is not just a simple power supply but it has built-in Volt-, Current-, and Frequency meters. The beauty of this project is that while you are prototyping your circuit, you can continuously monitor how much current your circuit draws at a specified operating voltage. This way you will know in advance how much power your design will require. The built-in frequency counter can measure frequencies up to 50.0 MHz.
DIY Multi-function power supply unit – [Link]
This project (posted on hobbydebraj) describes a simple spectrum analyzer based on a dsPIC30F4011 microcontroller. It uses Microchip’s FFT library codes to calculate the frequency spectrum of an input signal. The signal conditioning is achieved by a TL084 Op-amp IC. The peaks of spectrum are displayed on a graphics LCD. [via]
A simple spectrum analyzer using dsPIC30F4011 – [Link]
This Frequency Counter:
(a) works well into the RF range (I tested it to 50MHz and it was solid, unlike some of the posts here which stop working at a few hundred kHz)
(b) is extremely cheap (around $10),
(c) is portable, battery powered, and hand-held, and
(d) uses common components that are stocked at mouser.com so anyone build one! It’s based around an ATMega16 microcontroller reading frequency from a 74lv8154 dual 16-bit counter (acting as a 32 bit counter) and displays frequency on two multiplexed 3 character 7-segment displays.
$10 Frequency Counter – [Link]
There are many ways to determine the capacitance of a capacitor. You can use an oscillating circuit where the capacitor is a part of it and measure the frequency of oscillation to find the capacitance. Or, you can also use a resistor-capacitor network and measure the rate of voltage rise across the capacitor to determine the capacitance, if the value of the resistor is known.
Here’s a similar project where a PIC16F88 microcontroller measures the time required by a capacitor to charge through a known resistor from 0 to half of the reference voltage provided, and the capacitance is determined based on that information. [via]
Determine capacitance by measuring the charging time – [Link]
Measuring the frequency of a signal may seem to be a simple process of counting pulses, but in order to get better accuracy, few other things should be considered, such as the gating interval and the range of measurement. This tutorial, posted on the pcbheaven.com, briefly describes two typical methods of frequency measurement: Direct Frequency Measuring (DFM) and the Reverse Frequency Measuring (RFM), with their pros and cons. [via]
A brief tutorial on frequency measurements - [Link]
This is 60 MHz frequency meter / counter for measuring frequency from 10 Hz to 60 MHz with 10 Hz resolution. It is a very useful bench test equipment for testing and finding out the frequency of various devices with unknown frequency such as oscillators, radio receivers, transmitters, function generators, crystals, etc.
10Hz – 60MHz Frequency Meter / Counter – [Link]