Tag Archives: Clock


The quadrature LS7084 Module is a CMOS quadrature clock converter. Quadrature clocks derived from optical or magnetic encoders, when applied to the A and B inputs of the LS7084 are converted to strings of a Clock and an Up/down direction control. These outputs can be interfaced directly with standard Up/Down counters for direction and position sensing of the encoder.


  • Supply 5V DC
  • +4.5V to +10V operation (VDD – VSS)
  • On Board Power LED
  • J1 Encoder pulse multiplication ( Jumper JL Close =1X, Jumper JH Close = X4)
  • Header Connector for Encoder Interface
  • X1 and X4 mode selection
  • Programmable output clock pulse width
  • On-chip filtering of inputs for optical or magnetic encoder applications.
  • TTL and CMOS compatible I/Os
  • Up to 16MHz output clock frequency


RGBdigit clock

by Lucky @ elektormagazine.com build a LED display clock able to display temperature, humidity and air pressure. He writes:

What do you do when you want to design ‘something’ with a vintage or modern display? A clock of course, and this is our first design with RGBDigits: multi-colour 7-segment displays. With a BME280 breakout board attached it will also display temperature, humidity and air pressure. The clock is controlled by an ESP12 module, which makes it possible to synchronise the clock with an internet time server, change the clock settings from any mobile device or computer in the network, or transmit sensor data via Wi-Fi.

RGBdigit clock – [Link]

Making An Arduino I2C Digital Clock

Using Adafruit’s 0.56″ 7-segment LED backpack and display and the DS1307 RTC (Real Time Clock) board, this tutorial will guide you to make a simple 4-digit clock that uses only 2 Arduino pins.

The 7-Segment Backpack is a combination of the LED display, header pins, and a PCB which need to be soldered together. The PCB contains a driver chip with a built in clock that multiplexes the display and constant-current drivers for ultra-bright consistent color.

This module uses I2C interface, which means it needs just two data pins to control the 4 digits instead of 14 pin, freeing up Arduino pins for other usages.

DS1307 is a battery-backed real time clock (RTC) that allows a microcontroller project to keep track of time even if it is reprogrammed, or if the power is lost. DS1307 breakout board also comes as a kit of parts to be soldered.

Building the digital clock

It is a simple process, connect the part as shown in the image, the red wire connected with 5V, black wire with GND, orange to A4 (SDA – data), yellow to A5 (SCL – clock).

Both RTC and 7-segment modules have an Arduino library, as normal with libraries, unzip the folders into your Arduino ‘libraries’ directory and then restart the Arduino IDE for it to pick them up.

Paste the following sketch into a new Arduino window and upload it to your board. It will set the RTC to the time at which the sketch was compiled and uploaded. So, if your computer picks up its time from the Internet, that will be pretty accurate.

#include <Wire.h>
#include "Adafruit_LEDBackpack.h"
#include "Adafruit_GFX.h"
#include "RTClib.h"


Adafruit_7segment disp = Adafruit_7segment();

void setup()
 if (! RTC.isrunning())
   RTC.adjust(DateTime(__DATE__, __TIME__));

void loop()

int getDecimalTime()
 DateTime now = RTC.now();
 int decimalTime = now.hour() * 100 + now.minute();
 return decimalTime;

The full documentation of the project is reachable here.

Tiny LED Time Watch


David Johnson-Davies designed a minimalist ATtiny85-based watch using 12 LEDs, arranged like a clock face, to show the time in analogue-style. He writes:

To show the time you press the button on the watch face, and the time is then displayed for four seconds. It lights one LED to show the hour, and flashes another LED to show the minutes to the nearest five minutes, like the hour and minute hands on a clock. If only one LED lights up you know that both hands are pointing to the same hour mark.

Tiny LED Time Watch – [Link]


Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display


Nicu Florica blogged about his adjusting clock with alarm, hygrometer and thermometer on 1.8″ ST7735 display:

I use feature from article Another adjusting clock with alarm & thermometer using DS3231 on 1.8″ ST7735 display and change reading internal temperature of DS3231 with DHT22 sensor (AM2302), but you can use a cheaper and not very precise DHT11 sensor.
By using educ8stv_rtctft160_alarm_dht.ino or much better educ8stv_rtctft160_alarm_eeprom_dht.ino sketch, on display you can see: name of day, date, hour clock, hour alarm, temperature and humidity

Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display – [Link]

Yet another Arduino clock


Sverre Holm blogged about his Arduino clock project:

But I needed another Arduino project as I had made a K3NG morse keyer. I love this keyer because it is unique in supporting a display where you can see what you send. But I wasn’t using the morse keyer all the time, so I wanted the hardware to serve two purposes. That’s the excuse for also making a clock.

Yet another Arduino clock – [Link]

ICS501 simple frequency multiplier


Scott from SWHarden has published a new build:

Today I made a high frequency multiplier using a single component: the ICS501 PLL clock multiplier IC. This chip provides 2x, 5x, 8x (and more) clock multiplication using an internal phased-lock loop (PLL). At less than a dollar on eBay, $1.55 on mouser, and $0.67 on Digikey, they don’t break the bank and I’m glad I have a few in my junk box! I have a 10MHz frequency standard which I want to use to measure some 1Hz (1pps) pulses with higher precision, so my general idea is to use a frequency multiplier circuit to increase the frequency (to 80 MHz) and use this to run a counter IC to measure the number of clock pulses between the PPS pulses.

ICS501 simple frequency multiplier – [Link]

ESP8266-based Clock Synchronized With Network Time Service

Thanks to Internet, the problem of time shifting in embedded and connected devices was solved using time synchronization over Internet.

National Institute of Standards and Technology provides a service called Network Time Service (NTS) over the Internet. The project of ESP8266-based clock, published on embedded-lab, is going to demonstrate how to make a benefit from NTS to accomplish time synchronization over the Internet.

This clock retrieves time information from NTS and display it on a 4-digit seven segment LED display, and the connection to NIST time server through your local WiFi network will be by using ESP-01 WiFi module.


The 4-digit seven segment LED display breakout includes MAX7219 IC which is a seven segment driver. Three GPIO pins from ESP8266 module are used, where MAX7219 needs one for serial input,one for clock line and one to drive LOAD pin of MAX7219.



The firmware was developed using Arduino core for ESP8266. The firmware queries the time from NTS with 2-minutes interval that because NIST does not allow queries to any of their servers more frequently than once every 4 seconds, according to the blog post. During the 2-minutes, time display is kept running locally using the delay() routine.

To see the full instructions and to download the code you can visit the embedded-lab blog.


IN-4 Nixie Clock using ATmega168


andrea biffi @ instructables.com has a detailed tutorial on how to build your own Nixie clock using IN-4 tubes and Atmel ATMega168 microcontroller.

Nixies are neon valve tubes, where ten cathodes have shape of digits and are lighted up by plasma when high voltage flows through them. I love these old era displays, which have been employed in last century before I was born.

In last year I’ve been slowly collecting components and knowledge to build some nixie clocks as Max Pierson’s beautiful creation, I like the old style, the roundness of glass tubes, the rough wood case, the simplicity of the design. That clock has definitely inspired my project. Even though I really love vertical digits arrangement I keep that original feature for my next clock.

IN-4 Nixie Clock using ATmega168 – [Link]

ESP8266 Desktop Clock – WiFi Synchronised


This project is a wifi synchronised desktop clock using 7-segment displays. The heart of the project is a ESP8266 board.

The ESP8266 is a awesome chip; with integrated WiFi, 80MHz clock speed, total 160kb RAM, 512kb of flash memory, and a ton of other features, it makes a regular Arduino look like a joke. The project shown in this Instructable is based solely on the ESP8266-01 module, unlike several other projects on the web where it is used in tandem with another microcontroller. This makes it great demonstration of the capabilities of the ESP chip.

ESP8266 Desktop Clock – WiFi Synchronised – [Link]