OLED RTC ATtiny85
Real Time Clock DS3231 OLED display for time & date.
This project is about code that fits more functionality into small memory, the project is not an exercise in photography.
Downloads
Supplies
ATtiny85 or ATtiny45
DS3231 module from eBay (as photo)
OLED display module 0.96", SSD1306, I2C, 128x64 from eBay
2x pushbutton
OLED clock with ATtiny85 or ATtiny45 connected to RTC DS3231. The day month and year are displayed. MODE button selects what part off date to set, the part is marked with a line. Button INC changes the value.
ATtiny sets SQW to 1Hz it used to trigger time reading.
Sketch includes a lib tinyI2C that can be downloaded from GitHub: https://github.com/technoblogy/tiny-i2c/tree/master
ATtiny can be programmed using Arduino IDE and Arduino as ISP. Use these instructions https://gist.github.com/ij96/804e731bd31dbb95b2b043e93c79ceab with the difference of burning bootloader with setting "Clock Source 4MHz(internal)", this makes the CPU working at frequency of 4MHz.
For more info http://www.moty22.co.uk/tft_clock.php
Circuit
