This is a good looking and practical device that can be useful in many areas where countdown timer is needed. This project is based on the PIC16F84A microcontroller. The time range can be adjusted between 1 and 999 seconds. This project has 3 buttons and one of them is named Set Button. In order to regulate the seconds up or down on the display you should press the Set button while pressing the button on the left or the right hand side. The author of this project is @Pedja089. More photos on Facebook Fan Page.
Timer from 1 to 999s with PIC16F84A - [Link]
This is a countdown counter based on ATtiny2313, primary developed for my PCB exposure box, but it can be used for other purposes too.
The counting range is between 1 and 90 minutes and it can be adjusted with up or down buttons (high and low in the pictures).
After the desired time is set, the countdown starts by pressing the start/stop button (on/off in the pictures). By pressing the same button we can interrupt the counting at any time we want.
After the count expires we hear a beeping sound and the load is disconnected. By pressing start/stop button we reset the counter and we are ready for another lap. All actions included the time remaining are shown in the LCD display.
Pcb countdown timer - [Link]
In this Countdown Timer project, a 555 IC, a counter IC and a transistor switch to activate a relay either ON/OFF(mode selected by a jumper) as soon as the counting period is over. The circuit consists of an oscillator, a ripple counter and two switching transistors.
Simple Count Down timer Project – [Link]
This project is a big 7 segment countdown display using Christmas lights. The overall dimensions are 40′x40′ and the lights are hung from nearby trees. These display will start countdown the minutes an hour before new year and be synchronized with music. [via]
2011 New Years Count Down – [Link]
“Should I cut the blue wire… or the red…?”
This is a very common phrase in many movies when the action hero has a bomb in front of him with little time left and he has to choose which wire to cut and stop the bomb from exploding saving millions of people.
This game is just that… a count down timer and 4 wires of different colors.
The player has to remove each wire until it deactivates the bomb.
Bomb Game - [Link]
This is a simple countdown-timer-on-a-chip project – you program the PIC, attach some buttons and a pair of 2-segment LEDs, and you are done.
PIC16F690 Countdown Timer - [Link]
The purpose of this timer is to provide a countdown time from 1 second to 99 minutes & 59 seconds. I use it to control the lighting for the Ultra-Violet exposure of photosensitive PCB material. The project provides also an audible alarm at the end of the countdown time and switches the UV lights by means of a relay. It is based on a Microchip microcontroller, the 18 pin PIC16F84(A). This microcontroller contains 1Kbyte of flash memory for program code, 64bytes of static RAM memory, and 64bytes of EEPROM memory which are used here to store up to 15 different (user-programmable) countdown times. [via]
PIC16F84 Countdown timer for PCB exposure unit - [Link]