Arduino clock on TM1637 display

    I found a cheap led display some time ago, with TM1637 chip, has 4 digit 7-segment and 2 leds for seconds, so, I decided to made a clock using DS3231 RTC module clock:

   I use a simple schematic for this clock:

   Using TM1637_DS3231_clock0.ino sketch, my clock work as a .. clock :))) like in movie named Arduino clock with DS3231 on TM1637 display

   For hour litle than 10, on display we see 09

so, I change to simple 9

just changing few lines in sketch (TM1637_DS3231_cloc0a.ino).

   In Arduino clock with DS3231 on TM1637 display (2) movie, you cand see the diference on display and in sketch....
   Next step was to put an encoder (KY-040) to change hours and minutes, schematic is:

(also, I put an speaker/buzzer from PC between D7 and GND).

   For change hours, must long push (2-3 seconds) the push button from encoder, and you will see

so, must rotate clocwise to increase value or rotate antioclockwire (trigonometric sense) to decrease value for hour. When hour has desired value must push on button from encoder to enter in mode to change minutes:

   Procedure is similar, and after change value for minutes must push on button from encoder to enter in usual mode, as a claock.

    TM1637_DS3231_clock1.ino sketch must be used for have a clock like in my description or in Arduino clock with DS3231 on TM1637 display (3) movie:

27.04.2017
   This clock can be use also with DS1307 instead DS3231, just need a small change:

so, TM1637_DS3231_clock1a.ino have this chenage and few other for correct few bugs... in Arduino clock with DS3231 on TM1637 display (4)

PS: with last change, you can use DS1307 or DS3231 RTC clock module, without other modifcation.

Under & overvoltage relay for AC main power supply

   After I made a test for Measuring AC Main Supply Voltage with Arduino, now I change the sketch for made protection relay with adjustable limits for undervoltage, overvoltage and delay-off time using 3 buttons:

   After power the module, Arduino read and calculate vltage for AC main power supply and if is ok, coil relay is powered:

   If push MENU/OK button, on display is SET

after 2-3 seconds, on display is undervoltage threshold, who cand change using + & - buttons:

    After you push MENU/OK button, is displayed overvoltage thereshold, who cand change using + & - buttons:

   After you pus MENU/OK buttons on display is delay-off time for reconnect coil relay after voltage is outside good range, also you can change value form 1 tp 20 seconds using + & - buttons:

    After you push MENU/OK button, on display is main voltage:

   I write main_voltage_3.ino sketch who made exactlly in picture, but it more easy to understund cases if you see under & overvoltage relay with Arduino movie

Bibliography:

- Releu de protectie la minima si maxima tensiune retea

- Releu de protectie la minima si maxima tensiune retea (2)

- Masurare valoare tensiune retea (2)

- Measuring AC Voltage with an AC to AC power adapter

4-digit led display with TM1637 and Arduino

   A good and cheap display is 0.36" (9,14mm) led display drived by TM1637:

   On net I found some articles, but I liked article from http://www.arduino.md/hardware/lcd-and-leds/0-36-led-display-4-digit-red/ who use library from http://www.arduino.md/wp-content/uploads/library/TM1637-4-digit-display-tube.zip !!!

   Test schematic is very simple:

   I made few changes for can display special characters:

 after that, I put DHT11 sensor:

   Sketch for this weather station (temperature and humidity) is put at my github channel in TM1637 library !

   I made a movie named Arduino, TM1637 display & DHT11 sensor

   Original article is in roumanian language and can be find at http://nicuflorica.blogspot.ro/2016/04/afisaj-cu-4-cifre-controlate-de-tm1637.html !