RFID lock realization (Electronic lock)

   

Introduction

 

RFID (Radio Frequency Identification) is used in many areas: identification and tracking of packages, electronic animal tattoo, electronic toll system, in our case for access control. We find the products in various forms including labels, cards, badges, lights ...
For those interested, there are many books and sites describing RFID technology, I do not therefore develop its operations.
The assembly that I propose to achieve is a lock-based TAG available from Unique Lextronic . The assembly is also based on a module "ready" that overcomes the radio design of the device. Module UM005 has indeed the radio circuit and an embedded microcontroller, a result, the simple act of placing a tag near the antenna allows us to recover the TAG number (unique serial number) format 232.

The heart of the assembly built around a ATMEGA8 than enough for this application. It has 2 relay outputs to allow for differentiation according to the number of shares of TAG. A maximum of 20 TAG stored should be sufficient for an application to an individual. The first step will be to learn to mount the TAG has allowed the various relays operate with a programming mode accessible via three push buttons.

Schematic and PCB

Electronic schematic

The list of components

R1, R2: 2K2 Ohms R3, R4: 330 ohm C1: 47 uF / 25 V C2, C3, C4: 100 nF D1, D2, D3: 1N4148 D4: Green LED 3.5 mm D5: 3.5 mm bi-color LED Q1, Q2: 2N2222A L1: self 1mH FU1: 500mA fuse and fuse BUZ1: Buzzer 5 Volt

U1: 7805CT U2: Rfid Module UM005 U3: ATMEGA8 SW1, SW2, SW3: Push button "Micro Cosmos" or KSA RL1, RL2: Finder Relay 12 V 1 R / T (type 40.31) Misc: Support 28-pin dil 2 x 5 stackable connectors with a pitch of 5mm RFID antenna A 12 V power supply Tags of your choice!

The printed circuit board layout and

 

Construction and wiring

If you can, perform a manual tinning and in any case clean out the circuit using unscented alcohol or acetone ..

Board layout:

• At first, insert the single strap that is below U2
• C4 solder side solder plating on the printed circuit
• Following the installation proceeds as usual.
• Finish with the introduction of bi-color LED, the longest leg (red LED) is on the right.

Commissioning

The first step is to program the microcontroller with the HEX file provided.

Fuses are programmed in this way:

Boden Enable Bod level = 4V 8 MHz internal oscillator

After connecting the power supply will ensure that a TAG passing near the antenna that lights up and Ledverte Buz1 emits sound set!
However, no relay should be activated as no TAG is allowed. (The two-color LED confirms its way to red)

LEARNING MODE:

Press SW3 and SW1, SW3 release while still pressing SW1, the two-color LED turns red, then orange, from the moment release SW1, the LED blinks orange bicolor: you are in programming mode.

The next key press will select the relay number that you want the card recognized the active: SW1 and SW2 for REL1 REL2
Upon pressing a key, the LED turns red two-tone and look of your reading TAG: the LED turns orange at the first reading and want more to read the confirmation: Operation performed when the LED turns green to confirm recording. Otherwise if the TAG and misread it turns red, or if the TAG is already registered, it flashes red.
After the end of this phase, the LED blinks orange and look again pressing a button to record another TAG ...
Once completed the learning phase, restart the program by pressing SW3 (reset).
You can now check how your assembly from the front of the antenna allowed TAG: if it is recognized the two-color LED turns green and the corresponding relay output activates. Otherwise the LED indicates a misreading or a TAG unauthorized lighting up red.

ERASE MODE:

It is possible to erase the memory of the microcontroller without the board by the programmer, why simply press SW1 SW2 SW3 simultaneously, then release SW3: the two-color LED changes from red, orange green to complete the operation Clear.

All files to run RFID lock "basic" sound here.