User's Manual

AVR2044

8339A-AVR-09/10

Figure 5-1. Radio Controller Board - Block Diagram

The radio transceiver incorporates MAC hardware accelerators to handle all actions

concerning RF modulation/demodulation, signal processing, frame reception and

transmission. Further information about the radio transceiver and the microcontroller

are provided in the datasheet, see reference [1].

The RF front-end implementation was kept minimal by using a balun with integrated

filter. An antenna, provided with the RCB, has to be connected to the SMA connector.

All components are placed on one PCB side to demonstrate a low cost manufacturing

solution.

5.1 Power Supply

The RCB is powered by a single supply voltage in the range of 1.8 V – 3.6 V, which

makes it possible to use 1.5 V alkaline cells. Optionally, the power can be supplied

from a base board. In this case the power switch SW1 must be in OFF position or the

battery has to be removed from the battery holder.

All PCB components are supplied by this single supply to minimize the bill of material

(BoM) and maximize the power efficiency.

5.1.1 Battery power

For autonomous operation, the RCB can be supplied by two AAA batteries to be

inserted in the battery clip on the back side of the RCB. Use power switch SW1 to

manually switch on/off the board. Note, a power cycle may not be detected if radio

transceiver and microcontroller are in sleep mode, and all periphery disabled.

5.1.2 External power

An RCB mounted on a base board may be powered via the expansion connectors,

see Table 5-2. In this case the power switch SW1 has to be in OFF position to avoid

unintentionally charging of the batteries, if they are applied.

5.2 Microcontroller

The ATmega128RFA1 integrates a low-power 8-bit microcontroller based on the AVR

enhanced RISC architecture. The non-volatile flash program memory of 128 kB and

kHz

MHz

ATmega128RFA1

Expansion

Connector

EEPROM

LEDs

Pushbutton

Expansion

Connector

Balun