RFID Application Kit ATAK2270 User Manual 3-1
4871E–RFID–04/08
Section 3Description of the Application Board System3.1 System Overview
The ATAK2270 application board unit (Figure 2-3) consists of a ready-to-run standard microcontroller
main board equipped with the Atmel AVR® microcontroller ATmega8515L, combined with a piggybacked
antenna interface board containing the U2270B reader IC.
The following functionality is controlled by the AVR microcontroller:
Handling of the bi-directional data communication between the RS232 interface and the host PC
Execution of the read and write commands to be sent to the antenna interface
Decoding of the specific read data delivered by the antenna interface
The source program is written in C, and the compiled hex code is loaded in the 8-kByte Flash of the
microcontroller.
3.2 Power Supply
To operate the reader board, an external power supply in the range of DC 10V to 15V/200 mA has to be
connected to the jack, alternatively use the mains SMPS. A bridge rectifier placed at the connector input
is used for polarity independence.
3.3 Antenna Interface
The antenna interface (Figure 2-2) is supplied and controlled by the main board via header pin X2/1. The
current power supply voltage is indicated by LED1, Power. To adapt a specific antenna coil to the reso-
nant frequency and the Q factor, the components CANT1/CANT2 and R14 (Figure 2-2) can be changed.
For the antenna included in the kit, the parameters are matched as follows:
Resonant frequency: fres = 125 kHz ±1%, adjusted by CANT1/CANT2 with jumper 3 in
position dis
Whole antenna quality factor: Q = 20, adjusted by R14