To familiarize myself with a DS3231 RTC (real time clock), I built a simple arduino based 24 hour clock. It has 3 buttons with the following functions: press any button to enter the time setting mode, increase and decrease the time in minutes with two of the buttons, and set the clock with the third button. You can checkout a video of it working at vimeo.com/andrewideas/simplearduinoclock.
- An arduino development board (I used an Uno)
- A standard 16x2 HD44780 based LCD display
- A DS3231 based RTC (I got mine on Amazon)
- Three push buttons
- Three resistors (~10K ohm)
- A potentiometer (~10K ohm)
- A breadboard
- Several jumper wires
Step 1: Wiring
Refer to the drawing for wiring instructions. The buttons are connected to pins A0, A1, and A2. The RTC uses pin A5 for SCL and pin A4 for SDA. The potentiometer varies the contrast on the LCD and the LCD uses digital pins 2 through 7.
Step 2: Programming
Use the arduino IDE to upload my sketch to your arduino.
My code was partly based on the code provided here. And, of course, my code is explained in its comments.
You can download the sketch from this instructable.
Step 3: Continuing on With Your Life
You did it! Unless you didn't- in which case comment below and I'll do my best to help you out. Otherwise, go on ahead and do even greater things!