Check this tutorial if you forgot how to get started with pic microcontrollers. Frequency measurement is an important issue in the field of electrical. Studying the pic microcontroller and lcd included in this project. Lcd frequency counter see also tft counter, led counter. The 16bit timer1 value has a higher resolution and thus can count faster pulses. I checked with two different pic16f628a and they easily go over. Each machine cycle or instruction cycle for a pic microcontroller consists of four clock cycles, which are named as q1, q2, q3, and q4. Functional description of pic16f877a functions and. The main circuit blocks of the frequency counter circuit are shown in the diagram below. Make a simple frequency counter using pic16f877a working.
Pic 16f628 frequency counter with rs232 output in a db9. Pic16f877a datasheet, pic16f877a pdf, pic16f877a data sheet, pic16f877a manual, pic16f877a pdf, pic16f877a, datenblatt, electronics pic16f877a, alldatasheet, free. Frequency counter using pic micro controller free download as. After introducing the pic16f877 and its programming, this book covers the fundamental techniques and advanced level techniques of embedded systems programming in a general sense. The lcd and driver module is a 2 lines 16 characters, it has 14 way connector. Im trying to modify a 6 digit led frequency counter that uses an integral pic16f648a, a mhz oscillator and an i2c coupled digital display.
Special 2 display counter for counting sets and reps. The brain of the unit is a pic 16f84 microcontroller. An article on a frequency counter pic project will be published detailing the practical application of capture and compare. Capture and compare with pic16f877a microcontroller. There is a table of baud rates in microchip data sheet ds33023a. 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. Pic 16f628 frequency counter with rs232 output in a db9 backshell. Frequency counter with pic and seven segment led display, with. Pic16f877a introduction, pinout, features, examples, datasheet. The translated document is available in pdf format on his website. The frequency counter makes the result positive before displaying it. First of all, well need the basic components required for the pic to run. Key features of the pic16f872 operating frequency dc 20 mhz.
Another way to get high resolution for low frequency measurement is to use a phase lock loop, such as the 74hc4046, and a 74hc390 dual decade counter, to multiply the frequency say, 60 hz, to 6000 hz. There is a very good builtin capture and compare ccp module in 16f877a, but it uses the rc2ccp1 pin as interrupt source. 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 think this is the better soulution for a frequency counter. Counter overflows are accumulated to give the total count in multiples of 65536. In this type of segments all the cathode terminals are made common and tied to gnd. Pic kit3 is a famous programmer used to upload code to microchip chips, how to program using pic kit3 is a good source to read. The signal has voltage limits as specified in the device data sheet but will typically be.
While pulse counting can be implemented using timer0s counter mode, it is limited to 8bit values. Ive been able to get it reprogrammed by using modified software that was written for 6 discrete leds running at either 4. A frequency counter is a useful addition to an engineers toolbox and you can create the design described on this page for free. How to make a simple frequency counter using pic16f877a. The block diagram of the pic16f872 architecture is shown in figure 11. The four features that you might make you use a 16f887 instead of a 16f877a are.
The program for the frequency counter is give below. Open source frequency counter diy kit with pic16f628a and mb506 prescaler 10hz 250mhz duration. The microcontroller clock is generated by an external 10mhz crystal. Frequency counter using pic micro controller microcontroller. Microchip pic16f877a, three leds blinking, code using c language, time delay 100 milliseconds. Implementation of pic based digital frequency counter citeseerx. Frequency counter using pic16f877a microcontroller. Microcontroller based power frequency meter the timer 1 is used. The basic hardware for the measurement circuit is depicted in fig. Microchip is willing to work with the customer who is.
Adding the current value of the counter at the end gives the total count. The frequency counter circuit is built around a member of the pic family of. A stepdown transformer with the specification of 220 volt to 12 volt has. This produces a single instruction cycle time of 0. The max frequency of timer0 is 14 of the cpu clock which is 1mhz, but there is internal prescaler and it can be set from 1 to 256. For other instructions not affecting any status bits, see section operations resulting from the execution of instructions can all be considered as manipulation of data in. Frequency counter with pic and 4 to 5digit led display.
When an event occures, the capture module, copies the current value of timer1 module. Pic18f2455255044554550 universal serial bus features. This is pic16f877a microcontroller based digital clock with 7segment display. Digital frequency meter with lcd display using pic16f877a. A stepdown transformer with the specification of 220 volt to 12 volt has been used. The microcontroller uses its internal 4mhz oscillator for the cpu clock. Most likely, the person doing so is engaged in theft of intellectual property. In this application, the pic 16f84a operated as a frequency counter which can read frequencies from 10 hz to 30 mhz. 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. Ill use a pic16f88, but youre free to use any microcontroller you prefer. Timers are used for the precise delay generation and also used to trigger an activity before and after a predetermined time and to measure the time elapsed between two successive events.
Pdf measurement of power frequency with higher accuracy. On the other hand, in the datasheet of 16f628a there is a requirement for the input. On the other hand, in the datasheet of 16f628a there is a requirement for the input pulse at ra4 to be with minimum width of 10ns which is 100mhz frequency. Commonly available crystals have a ppm specification of 30ppm to. The 8 seven segment displays are multiplexed using a johnson counter 4017 that activates a single output after each clock pulse. Interfacing seven segments with pic16f877a tutorials. Pic 16f628 frequency counter with rs232 output in a db9 backshell by jan panteltje. In this work, the complete design of advanced frequency counter is provided. Pic16f877a digital clock microcontroller based projects. In the same way as the lcd project this frequency counter circuit uses tmr1 in 16 bit counter mode to count the input signal edges. On the other hand, in the datasheet of 16f628a there is a requirement for the input pulse at ra4 to be with minimum width of 10ns which is 100mhz. Pdf frequency measurement is an important issue in the field of electrical. Microchip believes that its family of products is one of the mo st secure families of its kind on the market today, when used i n the intended manner and under normal conditions.
Again, the range of the counter can be extended by the use of the prescaler. The lcd display used is a state of the art, commonly available 16 characters dot matrix in one line unit. This is a little too low for the specification so use is made of the rtcc. Digital frequency meter with lcd display can be used to measure frequency of square wave. Microchip products meet the specification cont ained in their particular microchip data sheet. N several occasions counting is required, but manual counting. Measurement of power frequency with higher accuracy using pic. The program ash memory can be programmed in the circuit through pins 36, 39, and 40 using the ccs icds40 incircuit programmer. Pic16f877a datasheet pdf microcontrollers microchip, pic16f877a pdf, pic16f877a pinout, pic16f877a data, circuit, output, ic, pic16f877a schematic. Keywords power frequency, zerocrossing detector, pic microcontroller. So the maximum frequency can be between 100mhz and 256mhz.
The hardware is simple and the main blocks are shown in the diagram below. With little bit modification in this embedded systems project you can also measure frequency of sine wave. Pdf construction of pic based digital frequency meter tolga. In this digital frequency meter pic16f877a microcontroller is used to measure frequency with the help of external interrupt and 16 2 lcd is used. Simple frequency meter using pic 16f877 embedologist. In this type of segments all the anodes terminals are made common and tied to vcc5v. This frequency counter contains only a few components. The gate could be used to more accurately capture an input time e. Microchip pic16f877a, three leds blinking, code using c. In theory this can allow the input signal to be up to 256mhz.
Thus the segments a to g needs a logic high signal5v in order to glow common anode. Pic16f877a datasheet pdf microcontrollers microchip. Frequency counter using pic micro controller free download as word. Main consideration for choosing the display should be current required as pic outputs can provide about 25ma for each segment. Interfacing a 7 segment display with a pic16f microcontroller. Thus the segments a to g needs a logic low signalgnd in order to glow below table shows the binaryhex values for.
587 505 1484 1395 1299 404 152 1305 1436 518 1223 798 6 776 1434 920 559 1325 528 790 931 803 714 1215 1464 1200 225 338 294 470 648 646 320 476 500 967 76 1259 344