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6.4 Buttons and LEDs

On the CC85xx Headset board there is a rocker switch and 2 LEDs to be used for “human

interaction”. This switch actually has 5 positions i.e. IN, UP, DOWN, HALFWAY UP and HALFWAY

DOWN, but the positions HALFWAY UP and HALFWAY DOWN are not in use. This can also be

seen from the schematic (Appendix A). Table 1 shows the button positions and the signals they

assert, as well as out-of-the-box functionality tied to these signals.

Table 1: Human interaction signal mapping

Button position

CC85xx pin

Out-of-the-box functionality

IN

CSN

Pairing button and power toggling

UP

GIO1

Slave: volume up, Master: no function

DOWN

GIO3

Slave: volume down, Master: no function

HALFWAY UP

NC

-

HALFWAY DOWN

NC

-

LED (D2) is connected to the CC85xx pin GIO12, and the intended usage of this diode is as a

network status LED. For details on how to configure the network LED please see the PurePath

Wireless Configurator [4]. The other LED (D3) is connected to the charger IC BQ25015 (for more

details see section 6.2).

6.5 RF Performance

The CC85xx Headset board does not have the output connected to a SMA connector, it is only

connected to an inverted F antenna. However, the output power measured into a 50 0hm load as

shown in Figure 6, is approximately 9 dBm. Please note that the supply voltage of the board is

approximately 2.15V. Note that to achieve maximum output power the supply voltage of the board

must be raised from 2.15V to 3.3V. This can be done by changing the ratio between the BQ25015

feedback resistors according to eq 8 in the BQ25015 datasheet [14]. The audio link is sustained for

input signals above -87dBm. Hence, a total link budget of 96 dB can be archived with the CC85xx

Headset board.

Finally, the design is pre-scanned for ETSI and FCC compliance, and the CC85xx Headset board

is suitable to fulfill these specifications.