User's Manual

4
AVR2042
8334A-AVR-11/10
Table 4-1. REB-CBB mechanical dimensions.
Dimension Value
Width x 57mm
Width y 60mm
PCB standoff height 5mm
Height without REB 18mm
Height with REB231ED plugged in 70mm
5 Functional description
The Atmel REB-CBB carries a high-performance Atmel AVR XMEGA microcontroller,
which connects to the radio extender board and various peripheral units (see Figure
5-1). It is powered by two AAA batteries or optionall
y by applying an external voltage
source.
Figure 5-1. REB-CBB block diagram.
5.1 Power supply
The board is powered by two AAA batteries. The power switch, SW1, disconnects
batteries from the entire board. External power is not routed through the power
switch.
For debugging and test purposes, power can also be supplied at pin header PWR.
Note - there is no protection against over voltage. Take care when applying power
from an external source. Refer to Section 7.1 fo
r allowable input voltage range.
Exceeding these limits may destroy the board. In addition, avoid applying reverse
currents into batteries by switching SW1 to the off position, or by removing the
batteries when using external power.
Figure 5-2. Power supply of the REB-CBB.