“I’ve had this issue for a while where people seemingly don’t value my privacy as much as i do myself and just barge into my room whenever they feel like it without any warning. So since i had this assignment coming up for my first year at MCT (a dutch course at Howest Kortrijk). I had chosen to make a lock that could be opened without getting up from my desk.
A few weeks after deciding on this idea there was an accident where the house behind my dormitory caught fire, and whilst evacuating i thought of making this lock even more safe with a few buildt in sensors that would monitor the room temperature, humidity and air level. The lock would also get an RFID reader for an ease of access so that a person can quickly vacate the room in an emergency.
So following that little intro, i will show you exactly how to build this lock step-by-step.
Supplies:
Components:
1602 LCD-display
RFID C522
DHT11 humidity sensor
TIP122 transistor
MQ-2 smoke sensor
DS18B20 One-wire temperature sensor
Solenoid with push-pull configuration
Breadboard power supply
MCP3008 SPI chip
PCF8574 I2C chip
corresponding RaspberryPi power supply
RaspberryPi (4B is used by me)
12V 650mA AC-DC power adapter
Ethernet cable
Potentiometer
T-cobbler for RaspberryPi GPIO pins
T-cobbler cable (for connecting between pi and cobbler)
Breadboard Full-size
SD-card with 16Gb or more of memory
9V or 12V AC-DC power adapter for breadboard power supply
powerstrip with 3 slots
80 (may be less) male-to-male jumper cables
80 (may be less) male-to-female jumper cables
resistors of different resistance (definitely 1K- ,470-, 10K- , 330 Ohm)
breakaway headers (for soldering onto components)
Materials and tools
soldering iron
woodworking tools
fine sandpaper
MDF
screws of smaller to bigger sizes
hot glue gun
some adhesive that sticks to wood and plastic
drill
hacksaw
You can find the Bill Of Materials attached with different sellers of every part and the base price, of course you can choose to use this document or not.”