Print PDF
Favorite
Email
Step 2Build the Arduino controller
The first step to building a RFID door lock with a basic Arduino is to bread board out a basic working arduino. Most Arduino pre-flashed ATMega 168 chips come with the default blink program pre installed. Connect a LED to digital output 13 and verify that everything is working.
The hardware portion of this RFID reader would be too simple if we used a regular arduino with built in USB programmer. Since I plan on putting this into the wall and not touching it again I dont want to use a big bulky $30 arduino board when I can buy a $5 ATMega 168 and make a much smaller custom PCB.
Because I chose to make a basic Arduino circuit myself I need an external USB->Serial FDIT programmer. I have included Eagle schematics of the controller with a power supply built from a 7805 voltage regulator. In testing I used a bread board power supply.
To get an arduino up and running all you really need is the ATMega168 with the arduino software flashed on it, 2x 22pF capacitors, 16mhz crystal, 10k ohm resistor, push button and a breadboard. The hookup for this is well known but I have included the entire schematic for the circuit.
The arduino is going to trigger 4 outputs, 1 each for Red/Green/Blue LEDs, and 1 to trigger the TIP31A to send 12vDC to the door lock. The arduino receives serial data in on its Rx line from the ID-20 RFID reader.
The hardware portion of this RFID reader would be too simple if we used a regular arduino with built in USB programmer. Since I plan on putting this into the wall and not touching it again I dont want to use a big bulky $30 arduino board when I can buy a $5 ATMega 168 and make a much smaller custom PCB.
Because I chose to make a basic Arduino circuit myself I need an external USB->Serial FDIT programmer. I have included Eagle schematics of the controller with a power supply built from a 7805 voltage regulator. In testing I used a bread board power supply.
To get an arduino up and running all you really need is the ATMega168 with the arduino software flashed on it, 2x 22pF capacitors, 16mhz crystal, 10k ohm resistor, push button and a breadboard. The hookup for this is well known but I have included the entire schematic for the circuit.
The arduino is going to trigger 4 outputs, 1 each for Red/Green/Blue LEDs, and 1 to trigger the TIP31A to send 12vDC to the door lock. The arduino receives serial data in on its Rx line from the ID-20 RFID reader.
Controller_PCB.pdf(612x792) 12 KB| « Previous Step | Download PDFView All Steps | Next Step » |
Is it the 1N4007 ?
Hope this helped!
If you have an arduino already, would it be possible to program the chip (ATMega168) and then put it onto the custom board? Would this save you from needing an external USB->Serial FDIT programmer?
Thanks.
Thanks
I added a jumper to the serial line so if you reprogrammed then you could "disconnect" the serial line. The Pro Mini has programming pins on the top so there are none on the PCB. Using a normal Arduino you would need the standard FDTI header to program.
I tried to make all the traces as large as possible and single sided PCB to make it easy for others to build It seems that double sided PCB is unavoidable building it from scratch.
I also setup the headers so that I could use Sparkfun 6 pin polarized pin headers to connect the two boards, or solder the reader side permanently and have a plug on just the controller side for installation purposes allowing you to seal up the reader to make it more tamper proof.
Let me know how your progress goes, I would love to get a PCB version made asap!
http://grab.by/3mL8
http://grab.by/3mLc
The reader is easy to make single sided. The controller is more difficult. I was able to do it with a few jumpers crossing the board. I am going to get some of the overhead transparencies and try to etch my own board. I have all the stuff for a single sided board.
I hope to etch it soon and will let you know how it goes. Your design looks super compact though. Ideally I would like to pick an enclosure for each of them that are readily available from an online electronics store then design a PCB to fit with the mounting holes etc included. Then send that out to a fab company and get a few made.