A digital clock with calendar & alarm using the ATTiny85

This is a fun project that I did. The accuracy of the clock over time is understandably low since I'm just using the internal oscillator of the ATTiny85.

This app is designed to work with a 6-digit, 7-segment display and due to the number of pins needed, uses two 74HC595 8-bit shift registers. There are two buttons MODE and SET to switch between the time, calendar and alarm screen and to set the time and alarm.

Usage

• The clock app has three screens - Time, Calendar and Alarm which can be cycled by pressing the MODE button.
• Once you are at any given screen and need to modify the values, press and hold the MODE button for approximately 3 seconds to enter the Edit Mode.
• Once you are in Edit Mode you can use the SET button to change the active blinking digit.
• Pressing MODE when in Edit Mode allows you to toggle between the digits.
• To exit Edit Mode, press and hold the MODE button again for 3 seconds to exit Edit Mode and enter the normal mode.
• The above applies to each of the three screens, including the alarm, for which the third screen allows you to set the alarm time and whether the alarm is enabled or disabled using the AE or Ad flag respectively.

Note: The date is displayed in DD-MM-YY and the time in 24-hour formats.

Proteus Simulation

• Use the Proteus file to simulate what has been described without using actual hardware.

Demo

Pre-requisties to compile and flash the program to MCU

Windows

Compiler

• Download and extract AVR GNU Toolchain for Windows and add the bin directory to PATH Windows Environment variable.

Flash Tools

• Download and extract avrdude to any location on your PC. Add the folder to Windows Environment variable PATH.

  (or)

• You can also use the Micronucleus bootloader. Download and add the folder commandline to path as before.

Debian/Ubuntu Linux

Compiler and Flash tools installation

• For Linux, follow the instructions available on this repository.

Compilation

• Use the following command to compile and create the HEX file in folder build

  make all
  

• Alternatively, Atmel Studio 7 project files are available.

Flashing to MCU

• Use make flashUSBasp to dump the created HEX file into your MCU. Script in Makefile uses avrdude and USBasp.

• If you are using Micronucleus, use make flashMicronucleus to do the same.

Circuit