Repo for Arduino based IoT project version 1.3: RFID activated maglock.

Apply 12VDC power supply of >6W. I used an old 40W laptop charger.

To Familiarize myself with MOSFET and 7805 Voltage Regulator components, while providing a practical application for an ongoing IoT porject.

• Gerber_doorswipepcb_20190104145725.zip

  • Contains Gerber files for custom printed PCB
    • C1 is implemented as an SMD package capacitor, but ceramic disk will fit just fine as well

• Prototype.jpg

  • Image of working prototype. Heatsinks are just pieces of scrap metal I found, stays warm to the touch. Voltage regulator is shown to the right of the MOSFET. .1uF Ceramic Disk Capacitor used to compensate for power ripples.

• Prototype.mp4

  • Video of prototype in action. Default code sets unlock period to 5 seconds.

• doorSwipe.ino

  • Source code for Arduino Nano. Comments included as seen fit.

• doorSwipe_v1.2.jpg

  • Screenshot of v1.2 schematic implemented with a Relay instead of F630 MOSFET.

• doorSwipe_v1.3.pdf

  • PDF of v1.3 schematic

Power Consumption:

• The status LED, RFID reader, and Nano add up to about 0.186W on standby
• About 4.2-4.5W under full load, mostly due to Electric Strike
• due to it only being under full load for 5 seconds only a couple times per day, I estimated a net of .3W power consumption.

Cost: 7.2Wh -> $0.37 to run per year (based on my cost of electricity)

I wanted to create my own 120VAC->12VDC power converter using a step down transformer and a full bridge rectifier, however I realized that this was way out of my scope of knowledge and presented a very real danger if done improperly. Plus I only had two weeks to complete this project, so I just scrounged up a spare power supply.

• Plan to implement ESP8266 WIFI module in the future and build an andriod app with MIT App Inventor that can lock and unlock the door, bypassing the need for RFID.
• Plan to add it to Central IoT processor (raspberry pi).