The automatic watering system simple just read the water level in the water bowl with a HC-SR04 Ultrasonic Sound Sensor. It measure the distance to the surface of the water. If the level is less then 3cm for more than 30sec it triggers a 5V relay whit a NO-contact . The relay are controlling a 12V DC supply to a mini watering pump in the water tank.
Hello world! Today i made a RFID door lock. The lamp acts as a Electric door lock because i don't have a electrical lock, you simply add the door lock to the relay instead of the lamp. I could not find much about the module, i have the RFID-RC522 in blue color, so this might be useful for the ones who have the same problem as me because the red one has the pins different...
Don't have components? Don't worry. Just click the component's name.
Step 2: Build Your Circuit.
Connect wire like the schematic above.
Step 3: Upload The Code.
You can uncomment this line below (line 68) in the code it will increase reading distance :
mfrc522.PCD_SetAntennaGain(mfrc522.RxGain_max);
Step 4: Test!
There is a button to clear the database. How this works is simple, Just hold the button and reset Arduino. Hold it for 6 second and it will clear all cards added. After that you need to add the new master card and key cards.
