Cybiko Functional Block Diagram

The tranceiver module is based on the IC RF2915, (RF MICRO-DEVICES INC) which was specially designed for wireless data transciever and IC LMXS2315. Functionally, the IC RF2915 provides a monolithic superhetrodyne receieve and a FM transmitter. The main building block (RSSI), FM demodulator and Data Amplifier. The receiver also utilizes the on-chip VCO. The FM transmitter includes variable gain amplifier, power amplifier (PA) and on chip VCO.

A message to be transmitted is packed by the MCU HD6472246 into frames with 50 or 200 bytes lengths and sent to the MCU AT90S2313. The MCU AT90S2313 encodes the frames by adding synchronization bits and sends with Manchester encoding.

The data stream coming from the controller AVR goes through a low-pass filter LPF1 to the varactor diode V1 that modulates the frequency of the VCO. The low-pass filter helps to limit the bandwidth occupied by the transmitter. RF signal from TX OUT RF2915 goes through RF filter to the permenantly attached antenna A1.

Receiving frequency modulation signal from antenna pass through RF filter in RX IN pin on RF2915. From out RF2915 (pin 29) the signal goes through a low-pass filter LPF2 to the AT90S2313 for decoding, and then frames come to the MCU6472246 for further processing.

The DC/DC converters LT1613 and LT1615 are used to generate a fixed power supply voltage of 3.3V for all IC and 17.8V for LCD.

The DC/DC converters is designed for the application of 2 NiMa cells.
The LMX2315 is high performance frequency synthesizers with integrated prescalers.

Serial data is transferred into the LMX2315 from the MCU AT90S2313 via a three line interface (Data, Enable, Clock)

the PCF8593 is a CMOS clock/calendar circuit, optimized for low power consumption.
Addresses and data are transferred serially in the MCU via the two-line bi-directional I2C bus. He has built-in 32.768kHz oscillator circuit.

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