nrfcxx::board Namespace Reference

Namespace holding board-specific configuration data. More...

Data Structures
class	iox_pin
	Extension of gpio::generic_pin using the SX1509B IO extender. More...
class	power_monitor
	Support for the power source interface. More...

Functions
int	initialize (bool enable_hfxt=false)
	Perform board-specific initialization. More...
static constexpr unsigned int	default_lfclk_src ()
	Provide the LFCLKSRC value preferred by the board. More...
misc::sx1509b &	iox () noexcept
	Access the SX1509B instance. More...
unsigned int	battery_level_pptt (unsigned int batt_mV)
	Estimated battery level from measured voltage. More...
int	led_setup_battery_display (unsigned int batt_mV)
	Configure to display the battery level. More...
int	enable_led_driver (unsigned int iox_mask=0, bool linear=false) noexcept
	Enable the SX1509B LED driver functionality. More...
int	disable_led_driver () noexcept
	Enable the SX1509B LED driver functionality. More...
bool	external_antenna (int on)
	Query or control use of external antenna. More...
periph::QSPI &	mx25l32 () noexcept
	Access the QSPI instance for the on-board MX25L32.

Detailed Description

Namespace holding board-specific configuration data.

Most material is put into this namespace through the board-specific <nrfcxx/board.hpp> header.

Function Documentation

battery_level_pptt()

unsigned int nrfcxx::board::battery_level_pptt

(

unsigned int

batt_mV

)

Estimated battery level from measured voltage.

Note

This is meaningful only when the there is no external power source. When V_USB is non-zero the measured battery voltage is high even when the actual capacity is low, regardless of whether the battery is charging or not.

default_lfclk_src()

static constexpr unsigned int nrfcxx::board::default_lfclk_src ( )

staticconstexpr

Provide the LFCLKSRC value preferred by the board.

If the board has an installed 32 KiHz crystal this will be the crystal source; otherwise it will be the internal RC oscillator for which you probably want nrfcxx::clock to calibrate for you.

Returns

either CLOCK_LFCLKSRC_SRC_Xtal or CLOCK_LFCLKSRC_SRC_RC depending on board::has_lfxt.

disable_led_driver()

int nrfcxx::board::disable_led_driver ( )

noexcept

Enable the SX1509B LED driver functionality.

This disables the 2 MHz Clock and the LED clock. All six LED pins are configured as normal outputs, set.

enable_led_driver()

int nrfcxx::board::enable_led_driver ( unsigned int  iox_mask = 0, bool  linear = false  )

noexcept

Enable the SX1509B LED driver functionality.

This configures a 2 MHz Clock divided to 256 MHz for the LED driver.

Parameters

iox_mask	optional mask specifying a subset of LED pins to be configured for LED driver control. If zero is passed all LED pins will be configured.
linear	optionally use linear intensity interpretation. Default false produces logarithmic intensity, which suits human vision better for a graded sequence.

external_antenna()

bool nrfcxx::board::external_antenna

(

int

on

)

Query or control use of external antenna.

The Xenon has a SPDT switch that selects between the PCB antenna and the uFL socket. On power-up the PCB antenna is used. This function may be used to switch between the PCB and uFL antennas.

Parameters

on	positive to use the external antenna, zero to use the PCB antenna, negative to query current source without changing it.

Returns

true if the external antenna is being used, false if the PCB antenna is being used.

initialize()

int nrfcxx::board::initialize

(

bool

enable_hfxt = false

)

Perform board-specific initialization.

This function should be invoked at the start of main() to ensure the basic functionality expected of all boards is available.

Operations performed by the default implementation include:

• clock::initialize() is invoked passing enable_hfxt. This ensures the clock::uptime infrastructure is present.
• Other boards may need to provide other actions.

Returns

zero in almost all cases. If a negative value is returned some applications may be able to enter a failsafe mode.

iox()

misc::sx1509b& nrfcxx::board::iox ( )

noexcept

Access the SX1509B instance.

Certain assumptions are made about how the pins on this device will be used. All pins are configured in board::initialize() to the reference implementation defaults. LEDs function as expected, but do not support the SX1509B LED driver functionality.

Frequency information in the Clock and Misc registers is assumed to be under the complete control of enable_led_driver() and disable_led_driver().

Warning

This function must not be invoked before board::initialize().

led_setup_battery_display()

int nrfcxx::board::led_setup_battery_display

(

unsigned int

batt_mV

)

Configure to display the battery level.

This configures the lightwell red or green LEDs to display an estimate of battery level:

• Levels at or above 50% display as green, with dimmest display at 50% and brightest at 100%.
• Levels below 50% display as red, with dimmest display at 0% and brightest at 49.99%.

The configuration assumes the LED driver is enables, and sets the duration of the display is roughly 1 s. The positive return value is the bit mask, which should be used as:

rc = board::led_setup_battery_display(batt_mV);
if (0 <= rc) {
   board::iox().output_sct(0, rc); // enable the LED
   // wait long enough for the driver to start
   board::iox().output_sct(rc, 0); // clear the LED
}