A very simple easy to make Frequency counter project. This project is powered with small AT89C2051 microcontroller with LCD. Block Diagram of circuit is shown below. It can support a wide range of frequency input starting from 1Hz to ~16.5Mhz, rest depends on pin characteristics.

Theory of Operation
As we all know frequency of a signal is number of cycles per second. I made use of this logic to calculate frequency of the input signal.

8051 has two timers, Timer 0 is configured for 1 second delay to sample the input signal and Timer 1 is used as a counter to calculate number of cycles in that 1 second. If timer1 overflows then the overflow is counter in another register which is considered as the high byte of Frequency. Input signal is provided at P3.5/T1 which is input for Timer 1 in counter mode. LCD is connected to microcontroller port 1 in 4-bit mode. Currently program is using 2 Line LCD but it can be used for 1 line LCD too.

Program initializes the Timer0 in 16-bit mode with 50mS delay value, a tick value of 20 is loaded to have total delay of 1s (50 x 20 = 1000 mS). Timer 1 is configured in 16-bit counter mode. After a sample of 1 sec, we get the number of cycles hence the frequency of input signal from timer1 registers (TH1:TL1) and high byte of Frequency. So total 3 byte value is then converted to a decimal equivalent represented in hex. This decimal value is then updated to LCD. The whole process repeats again.

For any doubts and suggestions please use forum

Download: Frequency Counter using AT89C2051 and LCD (Assembly)
Tags Frequency Counter using AT89C2051 and LCD8051 projectsFrequency counter project
printer friendly create pdf of this news item

Submit comment

(Required; Min length 5)
(Required; will not be displayed)


Wed Apr 15 2015, 05:07 PM
@Bibek.. and everyone. Create threads if you need help. The chat box is just for chat
Wed Apr 15 2015, 05:06 PM
@mohd atif ..login..create a post/thread,then I can post a copy of the missing file
Mon Apr 13 2015, 07:03 PM
mohd atif
@experimenteruk I didn't get you
Sun Apr 12 2015, 04:18 AM
hello, i have made a digital clock using rtc DS12887 and AT89S52 with date n callender. Now i want to add alarm features to it.....can any body help me with the code in assembly language
Sun Apr 12 2015, 03:22 AM
Hello, I am planning to do simulaton of the ' 4-way traffic controller'. As a first stage of the project, I tried to compile the code given in this website in keil microvision which controls 4-way traffic . I am using AT89C51. But when I am trying to compile the code it shows an error " Device is not supported by Toolchain". Can u please help me...
Sat Apr 11 2015, 02:06 AM
Suryamoy Mondal
There is a little bit confusion to connect the rs232 connector to max232 ..By continuty test i cant able to find , which wire from the other side of the RS232 connector , i connect to max232..is there any colour coding?
Fri Apr 10 2015, 06:19 PM
@Suryamoy, The PC control software is provided within the package. Follow the steps to install and test it.
Fri Apr 10 2015, 05:24 PM
Suryamoy Mondal
my final year btech project is pc remote control..i have made the hardware and microcontroller prograaming from yours project..bt i cant able to implement in PC..so wht kind of software need for pc to access this..please sir reply me ..i need your help
Wed Apr 08 2015, 04:46 PM
@mohd atif If you create a thread, I may be able help
Tue Apr 07 2015, 03:59 PM
mohd atif
i am working on a project evm. i download the evm project from this site named Electronic Voting machine with Managed Control Unit . i face problem in this when i am trying to simulate this on proteus . there is an error " could not open MODDATA initializer file mem.bin" please help me to get out this problem



[email protected]
Sat Apr 18 2015, 05:02 PM
Sat Apr 18 2015, 04:26 PM
Sat Apr 18 2015, 12:57 PM
Tue Apr 14 2015, 06:14 PM
Tue Apr 14 2015, 03:41 PM
Mon Apr 13 2015, 03:51 PM
Wed Apr 08 2015, 07:02 PM
Mon Apr 06 2015, 07:07 AM
Forum Activity
gaurav7577 Avatar
Posted By gaurav7577
Fri Apr 17 2015, 03:26 PM
thanks ajay for ur concern .....passed out B.E.......
ajay_bhargav Avatar
Posted By ajay_bhargav
Fri Apr 17 2015, 12:49 PM
can you post screenshot or a picture of CRO output...
ajay_bhargav Avatar
Posted By ajay_bhargav
Fri Apr 17 2015, 12:45 PM
are you in a college or working?
ajay_bhargav Avatar
Posted By ajay_bhargav
Fri Apr 17 2015, 12:44 PM
GSM modem needs a power supply with minimum 2A pea...
ajay_bhargav Avatar
Posted By ajay_bhargav
Fri Apr 17 2015, 12:41 PM
check it on CRO with 10x probes, you will see a si...
mayank058 Avatar
Posted By mayank058
Fri Apr 17 2015, 11:03 AM
The output was low in the scope and I am using MCB...
gaurav7577 Avatar
Posted By gaurav7577
Fri Apr 17 2015, 10:13 AM
Hello friends, i wanna do embedded course ...
ExperimenterUK Avatar
Posted By ExperimenterUK
Fri Apr 17 2015, 05:30 AM
In simulation everything went good but I am not a...
mayank058 Avatar
Posted By mayank058
Fri Apr 17 2015, 04:49 AM
dear sir, Actually DAC output pin is 0.26..so I think bit 21 must be set to get output on PIN 0.26. In simulation everything went good but I am not able to get output on CRO by using the board.