Thermostat for recycle pump at heating system

   For heating system using wood or another solid combustible materials who use recycle pump, I design a simple thermostat to power the pump just if water temperature is bigger than desired temperature.
   Schematic is simple

   Tom, a friend of mine, made practical system with Arduino Nano on PCB:

Using DS18B20_thermostat.ino sketch system work like in this photo:

- when temperature of heating water is bellow than desired temperature pump is off

- when temperature of heating water is bigger then desired temperature pump is powered.

Tom made more tests with sistem:

    Tom made 2 movie (speak in romanian language):

- termostat cu Arduino

- Termostat pentru pompa de recirculare la centrala pe lemne

Animated Light Stairs

   This interesting project was made by Bogdan Arnautu, reader of my blogs. He use an ATmega8A-PU chip in this schematic (for 14 leds):

   In this video you can see how system work:

   You can use Atmega8A_Iluminat_inteligent_trepte.hex file with Khazama software.

   Few photos with system:

   I write my sketch using Arduino for 

- stairs with 16 light steps

- stairs with 17 light steps

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: