Electronic door lock

       In this blog You can see Electronic door lock system, where is used PIC microcontroler 18F45K20 and button matrix with 12 buttons (3x4).

            Here is the electrical scheme of this project:

          There is 3 columns and 4 rows, 4 LED's (green) for indication door open (correct password) and 4 LED's (red) door not open (incorrect password). Password consisting of 4 digits (4 numbers), and You checking is Your password correct or not with one button (Provera (Check)). 

             Also there is an LCD for showing messages. Messages which it showing are:

1. "Insert password"
2. When You inserting password, mesage is "Inserting pasword" (x4)
3. If You insert 5-th digit of password You'll get a message on LCD "Wrong password" and after few seconds on LCD is new message "Try again".
4. When You insert correct password You'll get message "Door open".

Next pictures presenting this messages:

You inserting password

"Wrong pasword"

Success! Door is open :)

                Also there is an DC motor, which purpose is, when door is open by password, to unlock door lock system.

Link for simulation of this Electronic door lock system.

Digital clock with Temperature information

       In this article, you can see how to make Digital clock using PIC microcontroller and 7 segment displays with temperature info on it.

       Realized digital clock you can see below:

       Electrical scheme of digital clock is below:

       How you can see, 7 segment displays are controlled with shift registers 74HC595. For control this shift registers, you need only 3 pins (one for Data (DS), one for Shift clock (SH_CP) and one for Storage clock (ST_CP)). Also you need to wire EN and MR pins of shift registers to GND and Vcc, respectively, to allow shift registers to work properly.

       Data is transferred from the one shift register to another through Q7' pin (view in data sheet).

       Information of temperature coming from temperature sensor DS18B20 (Dallas semiconductor) - one wire protocol. For measuring temperature it's using one pin (bidirectional) with pull-up resistor (4.7 kΩ - 10 kΩ).

       How it works you can see here.

       For more information contact me at djordjevicpoljak@gmail.com

       Enjoy!

Weather station - Data Logger

          In this article, you can see how to make Weather station device - Data Logger for measuring and storing measured values.

          It can measure atmospheric parameters like:

               - Wind speed [m/s] - [km/h],
               - Atmospheric Pressure [mBar],
               - Temperature [℃] - [℉],
               - Humidity [%],
               - Light intensity [lux],
               - LPG detection [%] and
               - Altitude [m].

          Weather station - Data Logger can be used in Botanical Garden, Libraries, Hospitals, Mines, etc, not only in Agriculture.

          All values of measured parameters can be stored on few medium like:
     
              - SD (Security Digital) card,
              - SMS (Short Message Service),
              - IoT cloud ThingSpeak

          Block diagram of Weather station is below:

          Electrical scheme of Weather station is posted below:

          When Weather station - Data Logger is start-up, first you need to set Language of device, it can be:
               - English,
               - Serbian,
               - Deutsch and
               - French.

         After that, you have to set actual time and time when weather station to stop the measuring.
       
         Next is settings of the Name of file if you storing measured values on SD card, reason of that is you doesn't need to delete previous measurement.
       
         When you storing measured values on SD card, and you are not near the device, and you need to know when pick up the device at the end of measuring. In that case, you need to set number of cell phone where you can receive SMS like notification of end of measuring.

          After that settings, on LCD display you get message of starting measuring and storing on SD card.

          When measuring is done, GSM SIM800l module send SMS on number you set before.

          Realized Weather station - Data Logger on protoboard is on this picture:

How it works you can see here.

Enjoy!