Arduino – Simple Bedside Clock
As a fan of things that ‘just work’, this quick project solved a night time problem very well. To see the time on waking in the middle of the night.
No bells and whistles, it’s clean, concise and accurate to something like 1 second a year (much better than some similar RTC modules).
The temperature sensor is inbuilt to the DS3231, a handy feature and for approx 73 cents they even arrive with the CR2032 battery on them !
The 150ohm resistor limits brightness to be great at night for the eyes and limits the current – this uses just an average of 16mA, when measured with a multimeter.
Example parts sources:
TFT screen
http://www.ebay.com/itm/2-2-inch-2-2-SPI-TFT-LCD-Display-module-240×320-ILI9341-51-AVR-STM32-ARM-PIC-/182350166341
(mine was only $4.50 but the above was the cheapest found on Ebay just now)
DS3231 RTC
http://www.ebay.com/itm/Arduino-DS3231-AT24C32-IIC-Module-Precision-RTC-Real-Time-Clock-Quare-Memory-/262123918224
Arduino Pro Mini 3.3V
http://www.ebay.com/itm/FTDI-Adapter-FT232RL-USB-zu-TTL-Serial-fur-3-3V-und-5V-fur-Arduino-PRO-Mini-/172456631436
Code is here: https://www.dropbox.com/s/da4dicfagvoxmn3/SimpleBedsideClock.ino
