A Arduino project
Arduino based kitchen timer seconds count down from multiples of minutes, buzzer notification when count down reaches zero.
The Arduino UNO is a microcontroller development board based on a 8 bit AVR mircocontroller. The development platform used is the Arduino IDE and there are a large number of open source libraries available, this makes it idea to experiment with common electronic components and to create simple electronic projects quickly.
The timer can perform count-downs from 1 to 99 minutes in 1 minute intervals. Upon powering up, "01 --" is shown. This indicates the initial setting of counting down from 1 minute. Pressing the single button will advance the count minutes by one minute and the LED display will be updated.
To activate the count-down, a long press (press and hold) on the button is required. The LED display will change and begin to display the count-down in minutes and seconds. When the count-down reaches zero, the buzzer will sound and the display changes to alternating dashes.
The only tool that you may need is a pair of wire cutter / strippers
Timing are done via the millis() function of the Arduino core library. Count-down timer vairable decreases every second. When the timer variable reaches zero, buzzer is activated and will only be silenced upon a keypress on the tactile button.
The 4 digits 7 segment LED module provides display capability. It is a passive device. A multiplexing library is used to show the count-down values. 12 IO pins are used for multiplexing, 4 of which controls the digits and the rest take care of the 7 segments + decimal point.
A single tactile button is also wired to accept user input.
For construction on a 170 point mini breadboard and Arduino wire mapping, use the above wiring layout.
Arduino source code for this project is here