AN #27 - Count up/down timer

This is a complete project. It can be compiled with the BASCOM-8051 info since it used the AT89C2051 with 2KB of code.



S.E. Timer can countdown from 1-99 seconds, 1-99 minutes or 1-99 hours.
Timer has 4+1 press buttons, UP, DOWN, MODE, START + RESET
UP, DOWN set time that we want to count down, MODE selects the unit (sec., min. or hours) that we want to count down. Once we set time and set MODE, we can start countdown sequence. After countdown the relay turns on. To restart Timer, we must press RESET button.
In the countdown mode no buttons except RESET are active.

Download source code in an27.zip
Download files in an27files.zip