In this post we are going to make 3 different digital clocks without RTC or Real Time Clock module.
We will be constructing 3 types of digital clocks:
One with I2C adapter for LCD display.
One without I2C adapter for LCD display .
The last one with NOKIA 5510 LCD display.
All three digital clocks will not sport a RTC module.
Digital Clock with I2C LCD Module (WITHOUT RTC)
The circuit consists of an arduino (you can use any Arduino board), a LCD display with I2C adapter, two push buttons and that’s all. You can power this circuit with 5V USB adapter or from 9V power supply (9V to Vin pin and GND to GND).
What is IIC or I2C or “I square C” Adapter for LCD Display?
The I2C adapter is used for reducing wire usage, which makes the project construction easier.
The I2C adapter module connection: Vcc to 5V and GND to GND, A4 to SDA and A5 to SCL.
This module has 16 output pins and 4 input pins, the 16 pins are soldered directly at back of the LCD. Out of the four input pins two are Vcc and GND and other two are Serial Clock and Serial data pins.
The blue cube on back of the module is used for adjusting the contrast of the LCD with a tiny screw driver. A jumper on left of the module controls the backlight and removing it will disable the backlight, addition to this we can also control backlight with code.
Arduino has built-in voltage regulator to give 5V output for I2C adapter module, so you can power the circuit with 9V without any worry.
You can set time by long pressing hours and minutes push buttons.
NOTE: One fancy feature with this clock is that it will greet you with “Good Moring”, “Good Afternoon”, “Good Evening” and “Good Night” messages depending on the time, this feature exists in all clocks explained in this article.
Download this I2C_LiquidCrystal Library before compiling: Click Here.
Program code for the above clock circuit diagram: Code Verified
Some beginners may prefer to use LCD display in traditional way i.e. connecting all the wires from LCD to Arduino and some may have difficulty in finding I2C module and some with some other reasons.
In this section we will construct the Digital Clock without RTC and without I2C module.
The circuit consists of couple of push buttons for time setting, a LCD, an Arduino board and one variable resistor for adjusting LCD contrast. The circuit can be powered by 5V via USB or with 9V supply.
My nick name is blogthor, I am a professional electronics engineer specialized in Embedded System. I am a experienced programmer and electronics hardware developer. I am the founder of this website, I am also a hobbyist, DIYer and a constant learner. I love to solve your technical queries via comment section.