Arduino adjusting clock with dual thermometers

original article in romanian language

   Inspired by Arduino Digital Clock & Thermometer article, I change the schematic for use 2 sensors DS18B20 instead DHT22 (DHT11) sensor:

   Bogdan Arnautu, a blog reader, test the clock:

    With uploaded clock_2ds18b20.ino sketch, Bogdan made clock with 2 thermometers video:

matrix mini clock with alarm, thermometer and hygrometer (3)

original article

    After few nights and days than test the clock, I change style for usualt temperature... without sign and normal C...

    Also, I change for positive and negative values 

- small than 10 degree Celsius

- bigger than -10 degree Celsius

- lower than -10 degree Celsius

   You can see in matrix mini clock with alarm, thermometer and hygrometer (3a) video nea display modes:

matrix mini clock with alarm, thermometer and hygrometer (2)

original article

   Because I use DHT22 (AM2302 sensor) am change the sketck (mini_clock_1_3_b.ino)  to see temperature with number after decimal point, like in next photo

- negative tmperature > -10 degree Celsius:

- negative temperature more than -10 degree Celsius

- positive temperature less than 10 degree Celsius

- positive temperature more than 10 degree Celsius

   See matrix mini clock with alarm, thermometer and hygrometer (2) video for new features:

matrix mini clock with alarm, thermometer and hygrometer

   After some time, I update project "mini clock" with DHT sensor, schematic is now

  

  Because, I realize in original program I haven't all characters I need, I "reverse engineer"-ing  file with characters using Hexadecimal to Binary Converter to made new charactes:

So, character are vertical and from up to down. so I design my characters:

     Now, my character file has new characters 😆

   For not be problems, I remane my file as and put near original file

So, for testing, I simulate al cases:

- low humitity (< 10%)

- normal humidity 

- 2-digit negative temperature:

- 1-digit negative temperature:

- 1-digit positive temperature:

- 2-digit positive temperature:

   Using my /mini_clock_1_3 sketch, I made matrix mini clock with alarm, thermometer and hygrometer

    I use DHT22 (AM2302) sensor so sketch is

and if you have DHT11 just change to

   I use RTC with DS3231, but work without changes with DS1307 (note; DS3231 is more accurate than DS1307)....

6 Digit 7 Segment HT1621 LCD Display Module with Arduino

   I buy from Gearbest an interesting lcd display with 6 digit 7-segment drived by HT1621 chip.

  I search informations about this display and Arduino development board and I find few articles, but more usefull was article from http://www.14core.com/wiring-the-6-digit-7-segment-2-4-inch-ht1621-lcd-display-module-on-microcontroller/. I test the schematic presented in article

with HT1621_test.ino sketch and on display is 23:45 clock with animated second and after 17 degree Celsius:

This mode can be see it on HT1621 6 digit 7 segment LCD display test video

   After some search and study I can put easy decimal point, so, using HT1621_test4.ino sketch, on display is a random hour clock with animated seconds indicator (between hour and minutes)

and random temperature (negative and positive)

   In HT1621 6 digit 7 segment LCD display - test 2 video you can see this display mode:

NTP clock using OLED Wemos Lolin ESP32

   I buy an interesting ESP32 development board module because it has built-in OLED display drived with SSD1306 chip (is classc 0.96" OLED display).

  I combine 2 sketches to use NTP clock data (see https://en.wikipedia.org/wiki/Network_Time_Protocol for more info). This sketch is ESP32_OLED_SSD1306_NTP_0.ino who use ESP32-OLED0.96-ssd1306 and NTPtimeESP libraries.

   You can see how is clock displayed on OLED display while whatching NTP clock using OLED Wemis Lolin ESP32 movie.

Matrix clock with alarm

   At begin of this year I find article Mini led clock and I test using changed sketch (mini_clock_1a.ino) and schematic

   Also, I made 2 movie:
- clock on matrix led display with MAX7219

- clock on matrix led display with MAX7219 (2)

   Now, I add alarm feature, schematic is now

   Using mini_clock_1_2.ino sketch now you can see data and if alarm is activate by pushing second button (if alarm is deactivate, on screen not apear text with them).
    I made matrix mini clock with alarm movie when you can see how clock work