The problem was the absence of library for pic microcontrolers. The idea is trying to generate a frequency, and show it at the display something like this, i have for example 2khz. Heathkit had a frequency counter out in 1971, and it was somewhere in. In this pic timer module tutorial we will study the existing pic timer modules. The microcontroller pic16f877 has 3 different timers. In this application, the pic 16f84a operated as a frequency counter which can read frequencies from 10 hz to 30 mhz. Here is a quick overview of the programming function menus. The basic hardware for the measurement circuit is depicted in fig. The lcd and driver module is a 2 lines 16 characters, it has 14 way connector. Note if you need more sensitivity, use 74ac04 or 74hc04 instead of 74hcu04 as u1. The most important part for the accuracy of the frequency counter is the time base setting circuit crystal resonator x1 and capacitors c4 and c5. Ive been able to get it reprogrammed by using modified software that was written for 6 discrete leds running at either 4.
Counter is designed on a double sided pth board and works on usb power or with external dc12v. A simple pic 18f4550 usb powered frequency counter. This way when input frequency is below 1mhz the resolution will be 1hz. I read also a couple of interesting articles concerning this matter on qst 2, and so i was encouraged to go ahead with the project. Simple 100mhz frequency counter which uses 6 digit ledread more. As you can see very simple and yet elegant schematic. This is a frequency counter with pic microcontroller.
The pic controller is incircuit programmable if the mc34064 reset circuit is not soldered to the pcb. This pic frequency counter project uses an lcd to display the frequency and pic timer 1 to. The maximum frequency depends on the speed of the microcontroller. Frequency counter pic software free download frequency. Koobook 1set 1hz50mhz frequency counter meter crystal oscillator digital tester meter diy kit 5digital led display. Frequency counter with pic and 4 to 5digit led display. But the downloadable software achive also contains a third firmware file counter3. The microcontroller counts the pulses for one sec and display the count on lcd screen. For instance, to observe an oscillators accuracy, to measure the mains frequency or to find out the rpm of a motor that is connected to an encoder. By adding couple of transistors and operation amplifier tl082, it is possible to lock the lc oscillator frequency.
This auto ranging pic16f84a frequency counter counts up to 3540mhz and has two separate input bnc connectors. The basic idea comes fromthe an592 microchip application note. The weeder frequency counter pic 16f84 port by peter cousens. Should i use the 10mhz as the pic oscillator assuming a 20mhz pic.
Fc3 is designed and developed for radio amateurs looking for economical frequency counter which can measure rf signal level at the same time. Again, the range of the counter can be extended by the use of the prescaler. The latest software version of the frequency counter is for radioamateur and noncommercial use downloadable from this page for free. Software notes, interrupt driven counting and time measurement.
How to easily make a 50mhz frequency counter using only a pic. Couple of weeks ago i purchased from ebay one of these amazingly cheap an useful modules with max7219 led driver and 8 digit led display. Frequency counter using pic16c5x 1, where you may find a simple software wich implements a frequency counter using a pic microcontroller. If the coarse measured frequency is way below 1 mhz, the prescaler is turned off to get the best possible frequency resolution. But i wanted to use 7segment led display, not lcd, so i found a second useful project. Tester sold on ebay and other sites thehwcaveunter modification. It was a pic based frequency counter build by amateur radio enthusiast wolfgang wolf buscher dl4yhf. The measured frequency is used as an offset value added to subsequent measurements. Software is more adaptable than hardware, it is much easier to change a line or two in the source code than to add another track to a pcb. The external clock source will be obtained from a 555 timer ic operating as an astable multivibrator, and will be fed to gp5t1cki pin 2 of pic12f683. Ve3vxo has also ported this code to the pic18 series. The latter includes several peripherals and just a few of them are used in this project. This frequency counter contains only a few components. Frequency counter construction schematics and source code.
Luckily, i found a great library for arduino and i reworked it to. Build your own pic based frequency counter radio boat anchor. Lcd frequency counter see also tft counter, led counter. Here is the screen shot for proteus design the input signal. The frequency meter is used to count the incoming pulses on particular pin for one sec. The main circuit blocks of the frequency counter circuit are shown in the diagram below.
This one exceeds 50 mhz, limited only by the pic s counter timer. This of course will increase the current consumption. Im trying to modify a 6 digit led frequency counter that uses an integral pic16f648a, a mhz oscillator and an i2c coupled digital display. We can use these timers for various important purposes. All you need is a pic microcontroller or any microcontroller that has a high speed timer input module and a 2 line lcd display the standard hd44780 one is the one used here. Since the 16bit counter can count up to 65535, the external clock source with frequency higher than this will overflow the timer1 counter, and generate the timer1 overflow interrupt. Additional clocking options for the dl4yhf frequency counter firmware by erich heinzle vk5hse. The program for the microcontroller is written in c and is compiled with mikroc for pic. The logic level on ra5 pin 4 of the pic 16f628 causes it to change from basic frequency counter mode to offset compensation mode. The brain of the unit is a pic 16f84 microcontroller.
The code compiles for the microchip 16f84, 16f84a, 16f628, 16f628a, and 16f648a running at 4 mhz. The counter is based on pic 16f870 and display the frequency on 7 segmen led displays. Each machine cycle or instruction cycle for a pic microcontroller consists of four clock cycles, which are named as q1, q2, q3, and q4. The specification of hardware or software of this counter may be changed the future.
Counter the whole counter design is based on the pic microcontroller 16f876a. Using little more than a pic16f628 and some sevensegment displays, its. Modifications to the dl4yhf 16f628 firmware allow other clock speeds to be used for the 16f628. The maximum clock frequency at the t0cki input is limited by the synchronization requirement with the internal clock. Software functions are presented inside the dashed area. It could be operated with even an ordinary 9v battery for a long period. It is used the method of measuring the 24bits 3bytes counter value from the prescaler, tmr0 timer 0 module and some other registers, such as option register. I will use an external modulo 256 highspeed counter to prescale the 100 mhz so that the highest frequency counted directly by the pic will be.
This is a pic keyer i wrote several years ago that can be used as an outboard keyer, internal to an existing rig, or as a cw beacon. Pic frequency counter with morse output its a little strange to blog about a project thats mostly software, but even if i dont explore the software design in depth i can at least describe the resulting instrument. The name pic initially referred to peripheral interface controller, and is currently expanded as programmable intelligent computer. Very simple pc frequency counter works up to 100mhz.
A prescale chip from neccel may be added with divide by 256 counters to achieve 3. Pic16f877 timer modules tutorials pic timer0 tutorial. It takes a text file, up to 2g, and computes the frequency of characters az. A frequency counter is a useful addition to an engineers toolbox and you can create the design described on this page for free. A pic frequency counter operating up to about 50 mhz. Wolfe claimed that his pic based frequency counter had a frequency range of 1hz to 50mhz with only a handful of. Im a student in a university of portugal, and im studying electrical engineering. The frequency meter implemented here counts the pulses coming on port pin rc0. Pic usually pronounced as pick is a family of microcontrollers made by microchip technology, derived from the pic1650 originally developed by general instrument s microelectronics division. In this frequency counter has very high performance and very easy to build and to use.
Counter simple rfmicrowave frequency counter matjaz vidmar, s53mv 2. Frequency counter project detailed here is based on pic18f4550 for which design and firmware software support is given by fox delta team. Risepro digital frequency counter bench frequency signal meter with ac power cable bnc test leads 10hz 2. This pic frequency counter circuit uses a multiplexed seven segment display to provide 8 digits and uses timer 1 to count edges of the input signal and timer 0 to count time it uses the simpler method of direct frequency measurement which means that the input event for which you want to obtain a frequency reading is used to directly increment a counter inside the pic. Since it uses a base pic that is easily programmable, and provides a usefull bit of bench test equipment at very low cost, it makes an ideal pic learning project. So far we used delay procedure to implement some delay in the program, that was counting up to a specific value, before the program could be continued.
Software selectable frequency range of 8 mhz to 32 khz. The 8 seven segment displays are multiplexed using a johnson counter 4017 that activates a single output after each clock pulse. Simple frequency meter using pic 16f877 embedologist. This simple frequency meter will give a 1 hz accuracy in the range from 1 hz to 67 khz approximately with a 16 mhz crystal. This pic software combines frequency counter and frequency lock functions. This is a port by peter cousens to the pic 16f84 of the 50mhz frequency counter kit originally available from weeder technologies. The lcd display used is a state of the art, commonly available 16 characters dot matrix in one line unit. This one exceeds 50 mhz, limited only by the pics countertimer. The instalation of this ic is strongly recommended after the frequency counter has been built and tested. What is the best way of generating counting periods of 0.
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