MCS ELECTRONICS BASCOM-AVR EM4095 RFID Reader User Manual page 10

10 BASCOM-AVR
You also need to set 'RESET via DTR' on the 'MCS Loader' TAB.
Now the program will start and show some info on the LCD. Each time you hold a
RFID tag before the antenna/coil, the TAG ID will be shown.
When you press S3, you can store an RFID. Press S3, and then hold the TAG before
the coil. When there is room , or the tag is new, it will be stored. Otherwise it will be
ignored. The TAG ID is also stored in EEPROM.
Now when you hold the tag before the coil, the relay is activated for 2 seconds.
The AN is very simple and you can change and extend it easily.
One nice idea from Gerhard : use one TAG as a master tag to be able to add/remove
tags.
Security
To make the code more secure you could add a delay so that a valid tag must be
received twice, so after the valid TAG, wait 1 second, and then start a new
measurement and check if the TAG is valid again.
This will prevent where a bit generator could be used to generate all possible codes.
With 64 bit times a second, it would take ages before it would work.
The other hack would be to listen with a long range 125 KHz antenna, and recording
all bits. A long range scanner would be very hard to make. It would be easier to open
the door with a crowbar.
When you open your door with this device, make sure you have a backup option like
a key in case there is no power. Also, when the door is opened by a magnetic door
opener, make sure it has the right quality for the entrance you want to protect.
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