Simple Digital Countdown Timer using 7-seg Display
Basic Level Skills: Not specified Thu Apr 08 2010, 12:38 pm

A very simple Digital countdown timer using 8051 and 7 segment displays. A perfect project for microcontroller starters.
Author has used BCD to 7-segment decoder for driving displays. each segment has its own decoder. so there is no multiplexing included for displays. Additionally there are 2 control switches one to Start/Pause and second to Reset the timer. There is a Buzzer added to indicate timer has expired.
The code for this project is written in assembly language. Timer 0 is used for 1 second timer delay. Code is written for a hardcode 10 minutes timer. So there is a lot of scope to expand this project according to your needs. You can take this project as a reference if you want to develop more on it.
The zip file includes code, schematic and proteus simulation file incase you want to try project before building it. Complete list of files in given below:
File List information:
1. Timer.asm - Assembly code for project.
2. timer.hex - Pre-assembled hex file.
3. Digital Countdown Timer.png - Schematic/circuit diagram
4. Digital Countdown Timer.DSN - Proteus simulation file
5. timersimulation.png - Simulation screenshot
Incase you have any doubts regarding this project please make use of forum: Rickey's World forum
Thanks to Prasad.K.Wagh (Kartikceleb) and his team for this contribution.
If you want to contribute your projects to website please email me at: contact[at]rickeyworld[dot]info
Tags Digital Countdown Timer7-segment countdown timer
- Author
- Prasad.K.Wagh
Description


A very simple Digital countdown timer using 8051 and 7 segment displays. A perfect project for microcontroller starters.
Author has used BCD to 7-segment decoder for driving displays. each segment has its own decoder. so there is no multiplexing included for displays. Additionally there are 2 control switches one to Start/Pause and second to Reset the timer. There is a Buzzer added to indicate timer has expired.
The code for this project is written in assembly language. Timer 0 is used for 1 second timer delay. Code is written for a hardcode 10 minutes timer. So there is a lot of scope to expand this project according to your needs. You can take this project as a reference if you want to develop more on it.
The zip file includes code, schematic and proteus simulation file incase you want to try project before building it. Complete list of files in given below:
File List information:
1. Timer.asm - Assembly code for project.
2. timer.hex - Pre-assembled hex file.
3. Digital Countdown Timer.png - Schematic/circuit diagram
4. Digital Countdown Timer.DSN - Proteus simulation file
5. timersimulation.png - Simulation screenshot
Incase you have any doubts regarding this project please make use of forum: Rickey's World forum
Thanks to Prasad.K.Wagh (Kartikceleb) and his team for this contribution.
If you want to contribute your projects to website please email me at: contact[at]rickeyworld[dot]info
Tags Digital Countdown Timer7-segment countdown timer
Filesize
94.57 kB
Downloads
38924
Rating
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Comments
boy donald
27 Oct 2014: 20:47 pm
I want to ask , why when I try to change the time ( minute ) can not be executed . thank you .
boydonald
29 Oct 2014: 06:27 am
Dear sir, thanks before. i have some project urgent for my school and my project need this digital countdown timer using 7 segmen display. but your project only show ten minutes countdown, i need your help, can you show me more to change the minute or set the time manually. thank you, sorry for disturbing you. sorry for my bad english.
02 Nov 2014: 12:45 pm
You will need to make changes in the source as this is a static timer. For changeable timer you will also need to add keys and provision for timer storage.
boy donald
03 Nov 2014: 08:01 am
thank you for replying. but the problem, I'm not too smart to add the key and change the terms of its time. i hope you can help my project, sory for my bad english.
03 Nov 2014: 10:18 am
We cannot provide you ready code or something but we can help you implement it. You need to be a little smart to understand what we say and then implement. Please create a forum topic to get more help on this project. we cannot keep posting in comments area.
boy donald
03 Nov 2014: 16:45 pm
Thank you for your attention , now I begin to understand what you are saying.
shaygan
01 May 2015: 12:12 pm
Hey I am mechanical eng student and I would like to make a countdown clock for my go-kart team but we need more digits , like MM,WW, DD, HH , mm , ss , ms (month , week , day , hour , minute , sec , milli sec) .. can anybody help and tell me to how make such thing in big scale ?
Ashna
15 Jul 2015: 19:10 pm
Hello Sir.... Do you have the report for the Digital countdown timer?
20 Jul 2015: 10:14 am
@Ashna If its not available in the ZIP file then we don't have it either. Whatever is submitted by the Author is uploaded here.
Abiola
05 Apr 2023: 03:07 am
What can I do to write count for 02:00 on edsim51
I want to make this timer count down to 02:00 minutes what will I do?
I want to make this timer count down to 02:00 minutes what will I do?
12 Apr 2023: 03:03 am
>I want to make this timer count down to 02:00 minutes what will I do?
You can get close by changing
MOV A,#09H ;SETTING FOR MINUTE to MOV A,#01H
This starts at 1.59.
Setting as 2.00 does not work as tha code cannot handle starting with zeroes.
Not that the timing is correct for a 12M crystal, not 11.0592MHz as used in the DSN file
You can get close by changing
MOV A,#09H ;SETTING FOR MINUTE to MOV A,#01H
This starts at 1.59.
Setting as 2.00 does not work as tha code cannot handle starting with zeroes.
Not that the timing is correct for a 12M crystal, not 11.0592MHz as used in the DSN file