LCD Clock - Draft clock based on the chip AVR Attiny2313
The clock is working a 24 hour period. The time is displayed in the format "hh: mm: ss" on the alphanumeric display of size 16 x 2 (columns x rows) with driver HD44780. The use of a backlit display gives the impression of great visual at night. Instead, use a full stop or semicolon blink I used options available in the Bascom and created their own simple animation changing every second.
With such simple design to evaluate the accuracy of the clock is good. Accuracy was +1 second / 48 hours.
Set the clock is simple with 3 buttons.
SW1 - is responsible for setting hours
SW2 - for setting minutes
SW3 - to go mode of setting time and allows for the approval of the timeout
To generate signal I used 16 bit counter built into the processor AVR Attiny2313 that the project is incremented with a frequency 8MHz/1024. To overwhelm 16 bit counter within 1 second to load the timer registers the value of ((2 ^ 16-1) - (8000000/1024)) = 57822.5 => 57822
Timer1 Overflow at the time of service is called interrupt set new values for Timera1, and the modification of global variables responsible for representing the current time.
About microcontroller AVR Attiny2313:
ATtiny2313 is 8-bit microcontroller made by Atmel, made in CMOS technology. Attiny2313 builds on RISC architecture. The processor contains 2kB flash memory without removing the stand, 128 bytes of RAM and 128 bytes memory EEPROM. ATtiny2313 has USART interface, 18 universal line input / output and two timers.
Features AVR uC:
*120 Powerful Instructions - Single Clock Cycle Execution
*20 MIPS Throughput at 20 MHz
*Programmable Watchdog Timer
*One 8-bit Timer/Counter with Separate Prescaler and Compare Mode
*One 16-bit Timer/Counter with Separate Prescaler, Compare and Capture Modes
*4 PWM Channels
*Universal Serial Interface
*Full Duplex USART
*18 Programmable I/O Lines
The device can be powered from a voltage unstable with a value of 7-15V, or directly stable voltage 5V. The voltage is required because of the LCD.