const HasLowFrequencyCrystal = true
const (
	D0	= P0_25	// UART TX
	D1	= P0_24	// UART RX
	D2	= P0_10	// NFC2
	D3	= P1_15	// LED1
	D4	= P1_10	// LED2
	D5	= P1_08
	D6	= P0_07
	D7	= P1_02	// Button
	D8	= P0_16	// NeoPixel
	D9	= P0_26
	D10	= P0_27
	D11	= P0_06
	D12	= P0_08
	D13	= P1_09
	D14	= P0_04	// A0
	D15	= P0_05	// A1
	D16	= P0_30	// A2
	D17	= P0_28	// A3
	D18	= P0_02	// A4
	D19	= P0_03	// A5
	D20	= P0_29	// Battery
	D21	= P0_31	// AREF
	D22	= P0_12	// I2C SDA
	D23	= P0_11	// I2C SCL
	D24	= P0_15	// SPI MISO
	D25	= P0_13	// SPI MOSI
	D26	= P0_14	// SPI SCK
	D27	= P0_19	// QSPI CLK
	D28	= P0_20	// QSPI CS
	D29	= P0_17	// QSPI Data 0
	D30	= P0_22	// QSPI Data 1
	D31	= P0_23	// QSPI Data 2
	D32	= P0_21	// QSPI Data 3
	D33	= P0_09	// NFC1 (test point on bottom of board)


const (
	A0	= D14
	A1	= D15
	A2	= D16
	A3	= D17
	A4	= D18
	A5	= D19
	A6	= D20	// Battery
	A7	= D21	// ARef

Analog Pins

const (
	LED		= D3
	LED1		= LED
	LED2		= D4
	WS2812		= D8

	QSPI_CS		= D28
const (

UART0 pins (logical UART1)

const (
	SDA_PIN	= D22	// I2C0 external
	SCL_PIN	= D23	// I2C0 external

I2C pins

const (
	SPI0_SCK_PIN	= D26	// SCK
	SPI0_SDO_PIN	= D25	// SDO
	SPI0_SDI_PIN	= D24	// SDI

SPI pins

const (
	P0_00	Pin	= 0
	P0_01	Pin	= 1
	P0_02	Pin	= 2
	P0_03	Pin	= 3
	P0_04	Pin	= 4
	P0_05	Pin	= 5
	P0_06	Pin	= 6
	P0_07	Pin	= 7
	P0_08	Pin	= 8
	P0_09	Pin	= 9
	P0_10	Pin	= 10
	P0_11	Pin	= 11
	P0_12	Pin	= 12
	P0_13	Pin	= 13
	P0_14	Pin	= 14
	P0_15	Pin	= 15
	P0_16	Pin	= 16
	P0_17	Pin	= 17
	P0_18	Pin	= 18
	P0_19	Pin	= 19
	P0_20	Pin	= 20
	P0_21	Pin	= 21
	P0_22	Pin	= 22
	P0_23	Pin	= 23
	P0_24	Pin	= 24
	P0_25	Pin	= 25
	P0_26	Pin	= 26
	P0_27	Pin	= 27
	P0_28	Pin	= 28
	P0_29	Pin	= 29
	P0_30	Pin	= 30
	P0_31	Pin	= 31
	P1_00	Pin	= 32
	P1_01	Pin	= 33
	P1_02	Pin	= 34
	P1_03	Pin	= 35
	P1_04	Pin	= 36
	P1_05	Pin	= 37
	P1_06	Pin	= 38
	P1_07	Pin	= 39
	P1_08	Pin	= 40
	P1_09	Pin	= 41
	P1_10	Pin	= 42
	P1_11	Pin	= 43
	P1_12	Pin	= 44
	P1_13	Pin	= 45
	P1_14	Pin	= 46
	P1_15	Pin	= 47

Hardware pins

const (
	TWI_FREQ_100KHZ	= 100000
	TWI_FREQ_400KHZ	= 400000

TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.

const Device = deviceName

Device is the running program’s chip name, such as “ATSAMD51J19A” or “nrf52840”. It is not the same as the CPU name.

The constant is some hardcoded default value if the program does not target a particular chip but instead runs in WebAssembly for example.

const NoPin = Pin(0xff)

NoPin explicitly indicates “not a pin”. Use this pin if you want to leave one of the pins in a peripheral unconfigured (if supported by the hardware).

const (
	PinInput		PinMode	= (nrf.GPIO_PIN_CNF_DIR_Input << nrf.GPIO_PIN_CNF_DIR_Pos) | (nrf.GPIO_PIN_CNF_INPUT_Connect << nrf.GPIO_PIN_CNF_INPUT_Pos)
	PinInputPullup		PinMode	= PinInput | (nrf.GPIO_PIN_CNF_PULL_Pullup << nrf.GPIO_PIN_CNF_PULL_Pos)
	PinInputPulldown	PinMode	= PinInput | (nrf.GPIO_PIN_CNF_PULL_Pulldown << nrf.GPIO_PIN_CNF_PULL_Pos)
	PinOutput		PinMode	= (nrf.GPIO_PIN_CNF_DIR_Output << nrf.GPIO_PIN_CNF_DIR_Pos) | (nrf.GPIO_PIN_CNF_INPUT_Connect << nrf.GPIO_PIN_CNF_INPUT_Pos)
const (
	PinRising	PinChange	= nrf.GPIOTE_CONFIG_POLARITY_LoToHi
	PinFalling	PinChange	= nrf.GPIOTE_CONFIG_POLARITY_HiToLo
	PinToggle	PinChange	= nrf.GPIOTE_CONFIG_POLARITY_Toggle

Pin change interrupt constants for SetInterrupt.

const (
const (
	// ParityNone means to not use any parity checking. This is
	// the most common setting.
	ParityNone	UARTParity	= 0

	// ParityEven means to expect that the total number of 1 bits sent
	// should be an even number.
	ParityEven	UARTParity	= 1

	// ParityOdd means to expect that the total number of 1 bits sent
	// should be an odd number.
	ParityOdd	UARTParity	= 2


var (
	DefaultUART = UART0
var (
	ErrTimeoutRNG		= errors.New("machine: RNG Timeout")
	ErrInvalidInputPin	= errors.New("machine: invalid input pin")
	ErrInvalidOutputPin	= errors.New("machine: invalid output pin")
	ErrInvalidClockPin	= errors.New("machine: invalid clock pin")
	ErrInvalidDataPin	= errors.New("machine: invalid data pin")
	ErrNoPinChangeChannel	= errors.New("machine: no channel available for pin interrupt")
var (
	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
var (
	// UART0 is the hardware UART on the NRF SoC.
	_UART0	= UART{Buffer: NewRingBuffer()}
	UART0	= &_UART0


var (
	I2C0	= (*I2C)(unsafe.Pointer(nrf.TWI0))
	I2C1	= (*I2C)(unsafe.Pointer(nrf.TWI1))

There are 2 I2C interfaces on the NRF.

var (
	PWM0	= &PWM{PWM: nrf.PWM0}
	PWM1	= &PWM{PWM: nrf.PWM1}
	PWM2	= &PWM{PWM: nrf.PWM2}
	PWM3	= &PWM{PWM: nrf.PWM3}


var (
	USB	= &_USB
	_USB	= USBCDC{Buffer: NewRingBuffer()}

	usbEndpointDescriptors	[8]usbDeviceDescriptor

	udd_ep_in_cache_buffer	[7][128]uint8
	udd_ep_out_cache_buffer	[7][128]uint8

	sendOnEP0DATADONE	struct {
		ptr	*byte
		count	int
	isEndpointHalt		= false
	isRemoteWakeUpEnabled	= false
	endPoints		= []uint32{usb_ENDPOINT_TYPE_CONTROL,
		(usb_ENDPOINT_TYPE_INTERRUPT | usbEndpointIn),
		(usb_ENDPOINT_TYPE_BULK | usbEndpointOut),
		(usb_ENDPOINT_TYPE_BULK | usbEndpointIn)}

	usbConfiguration		uint8
	usbSetInterface			uint8
	usbLineInfo			= cdcLineInfo{115200, 0x00, 0x00, 0x08, 0x00}
	epinen				uint32
	epouten				uint32
	easyDMABusy			volatile.Register8
	epout0data_setlinecoding	bool
var (
	SPI0	= SPI{Bus: nrf.SPIM0, buf: new([1]byte)}
	SPI1	= SPI{Bus: nrf.SPIM1, buf: new([1]byte)}
	SPI2	= SPI{Bus: nrf.SPIM2, buf: new([1]byte)}

There are 3 SPI interfaces on the NRF528xx.

var (
	ErrPWMPeriodTooLong = errors.New("pwm: period too long")
var Serial = USB

Serial is implemented via USB (USB-CDC).

func CPUFrequency

func CPUFrequency() uint32

func EnterOTABootloader

func EnterOTABootloader()

EnterOTABootloader resets the chip into the bootloader so that it can be flashed via an OTA update

func EnterSerialBootloader

func EnterSerialBootloader()

EnterSerialBootloader resets the chip into the serial bootloader. After reset, it can be flashed using serial/nrfutil.

func EnterUF2Bootloader

func EnterUF2Bootloader()

EnterUF2Bootloader resets the chip into the UF2 bootloader. After reset, it can be flashed via nrfutil or by copying a UF2 file to the mass storage device

func InitADC

func InitADC()

InitADC initializes the registers needed for ADC.

func NewACMFunctionalDescriptor

func NewACMFunctionalDescriptor(subtype, d0 uint8) ACMFunctionalDescriptor

NewACMFunctionalDescriptor returns a new USB ACMFunctionalDescriptor.

func NewCDCCSInterfaceDescriptor

func NewCDCCSInterfaceDescriptor(subtype, d0, d1 uint8) CDCCSInterfaceDescriptor

NewCDCCSInterfaceDescriptor returns a new USB CDCCSInterfaceDescriptor.

func NewCDCDescriptor

func NewCDCDescriptor(i IADDescriptor, c InterfaceDescriptor,
	h CDCCSInterfaceDescriptor,
	cm ACMFunctionalDescriptor,
	fd CDCCSInterfaceDescriptor,
	callm CMFunctionalDescriptor,
	ci EndpointDescriptor,
	di InterfaceDescriptor,
	outp EndpointDescriptor,
	inp EndpointDescriptor) CDCDescriptor

func NewCMFunctionalDescriptor

func NewCMFunctionalDescriptor(subtype, d0, d1 uint8) CMFunctionalDescriptor

NewCMFunctionalDescriptor returns a new USB CMFunctionalDescriptor.

func NewConfigDescriptor

func NewConfigDescriptor(totalLength uint16, interfaces uint8) ConfigDescriptor

NewConfigDescriptor returns a new USB ConfigDescriptor.

func NewDeviceDescriptor

func NewDeviceDescriptor(class, subClass, proto, packetSize0 uint8, vid, pid, version uint16, im, ip, is, configs uint8) DeviceDescriptor

NewDeviceDescriptor returns a USB DeviceDescriptor.

func NewEndpointDescriptor

func NewEndpointDescriptor(addr, attr uint8, packetSize uint16, interval uint8) EndpointDescriptor

NewEndpointDescriptor returns a new USB EndpointDescriptor.

func NewIADDescriptor

func NewIADDescriptor(firstInterface, count, class, subClass, protocol uint8) IADDescriptor

NewIADDescriptor returns a new USB IADDescriptor.

func NewInterfaceDescriptor

func NewInterfaceDescriptor(n, numEndpoints, class, subClass, protocol uint8) InterfaceDescriptor

NewInterfaceDescriptor returns a new USB InterfaceDescriptor.

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

type ACMFunctionalDescriptor

type ACMFunctionalDescriptor struct {
	len		uint8
	dtype		uint8	// 0x24
	subtype		uint8	// 1
	bmCapabilities	uint8

ACMFunctionalDescriptor is a Abstract Control Model (ACM) USB descriptor.

func (ACMFunctionalDescriptor) Bytes

func (d ACMFunctionalDescriptor) Bytes() [acmFunctionalDescriptorSize]byte

Bytes returns the ACMFunctionalDescriptor data.

type ADC

type ADC struct {
	Pin Pin

func (ADC) Configure

func (a ADC) Configure(ADCConfig)

Configure configures an ADC pin to be able to read analog data.

func (ADC) Get

func (a ADC) Get() uint16

Get returns the current value of a ADC pin in the range 0..0xffff.

type ADCConfig

type ADCConfig struct {
	Reference	uint32	// analog reference voltage (AREF) in millivolts
	Resolution	uint32	// number of bits for a single conversion (e.g., 8, 10, 12)
	Samples		uint32	// number of samples for a single conversion (e.g., 4, 8, 16, 32)

ADCConfig holds ADC configuration parameters. If left unspecified, the zero value of each parameter will use the peripheral’s default settings.

type CDCCSInterfaceDescriptor

type CDCCSInterfaceDescriptor struct {
	len	uint8	// 5
	dtype	uint8	// 0x24
	subtype	uint8
	d0	uint8
	d1	uint8

CDCCSInterfaceDescriptor is a CDC CS interface descriptor.

func (CDCCSInterfaceDescriptor) Bytes

func (d CDCCSInterfaceDescriptor) Bytes() [cdcCSInterfaceDescriptorSize]byte

Bytes returns CDCCSInterfaceDescriptor data.

type CDCDescriptor

type CDCDescriptor struct {
	//	IAD
	iad	IADDescriptor	// Only needed on compound device

	//	Control
	cif	InterfaceDescriptor
	header	CDCCSInterfaceDescriptor

	// CDC control
	controlManagement	ACMFunctionalDescriptor		// ACM
	functionalDescriptor	CDCCSInterfaceDescriptor	// CDC_UNION
	callManagement		CMFunctionalDescriptor		// Call Management
	cifin			EndpointDescriptor

	//	CDC Data
	dif	InterfaceDescriptor
	in	EndpointDescriptor
	out	EndpointDescriptor

CDCDescriptor is the Communication Device Class (CDC) descriptor.

func (CDCDescriptor) Bytes

func (d CDCDescriptor) Bytes() [cdcSize]byte

Bytes returns CDCDescriptor data.

type CMFunctionalDescriptor

type CMFunctionalDescriptor struct {
	bFunctionLength		uint8
	bDescriptorType		uint8	// 0x24
	bDescriptorSubtype	uint8	// 1
	bmCapabilities		uint8
	bDataInterface		uint8

CMFunctionalDescriptor is the functional descriptor general format.

func (CMFunctionalDescriptor) Bytes

func (d CMFunctionalDescriptor) Bytes() [cmFunctionalDescriptorSize]byte

Bytes returns the CMFunctionalDescriptor data.

type ConfigDescriptor

type ConfigDescriptor struct {
	bLength			uint8	// 9
	bDescriptorType		uint8	// 2
	wTotalLength		uint16	// total length
	bNumInterfaces		uint8
	bConfigurationValue	uint8
	iConfiguration		uint8
	bmAttributes		uint8
	bMaxPower		uint8

ConfigDescriptor implements the standard USB configuration descriptor.

Table 9-10. Standard Configuration Descriptor bLength, bDescriptorType, wTotalLength, bNumInterfaces, bConfigurationValue, iConfiguration bmAttributes, bMaxPower

func (ConfigDescriptor) Bytes

func (d ConfigDescriptor) Bytes() [configDescriptorSize]byte

Bytes returns ConfigDescriptor data.

type DeviceDescriptor

type DeviceDescriptor struct {
	bLength			uint8	// 18
	bDescriptorType		uint8	// 1 USB_DEVICE_DESCRIPTOR_TYPE
	bcdUSB			uint16	// 0x200
	bDeviceClass		uint8
	bDeviceSubClass		uint8
	bDeviceProtocol		uint8
	bMaxPacketSize0		uint8	// Packet 0
	idVendor		uint16
	idProduct		uint16
	bcdDevice		uint16	// 0x100
	iManufacturer		uint8
	iProduct		uint8
	iSerialNumber		uint8
	bNumConfigurations	uint8

DeviceDescriptor implements the USB standard device descriptor.

Table 9-8. Standard Device Descriptor bLength, bDescriptorType, bcdUSB, bDeviceClass, bDeviceSubClass, bDeviceProtocol, bMaxPacketSize0, idVendor, idProduct, bcdDevice, iManufacturer, iProduct, iSerialNumber, bNumConfigurations */

func (DeviceDescriptor) Bytes

func (d DeviceDescriptor) Bytes() [deviceDescriptorSize]byte

Bytes returns DeviceDescriptor data

type EndpointDescriptor

type EndpointDescriptor struct {
	bLength			uint8	// 7
	bDescriptorType		uint8	// 5
	bEndpointAddress	uint8
	bmAttributes		uint8
	wMaxPacketSize		uint16
	bInterval		uint8

EndpointDescriptor implements the standard USB endpoint descriptor.

Table 9-13. Standard Endpoint Descriptor bLength, bDescriptorType, bEndpointAddress, bmAttributes, wMaxPacketSize, bInterval

func (EndpointDescriptor) Bytes

func (d EndpointDescriptor) Bytes() [endpointDescriptorSize]byte

Bytes returns EndpointDescriptor data.

type I2C

type I2C struct {
	Bus nrf.TWI_Type

I2C on the NRF.

func (*I2C) Configure

func (i2c *I2C) Configure(config I2CConfig) error

Configure is intended to setup the I2C interface.

func (*I2C) ReadRegister

func (i2c *I2C) ReadRegister(address uint8, register uint8, data []byte) error

ReadRegister transmits the register, restarts the connection as a read operation, and reads the response.

Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily read such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.

func (*I2C) Tx

func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error)

Tx does a single I2C transaction at the specified address. It clocks out the given address, writes the bytes in w, reads back len(r) bytes and stores them in r, and generates a stop condition on the bus.

func (*I2C) WriteRegister

func (i2c *I2C) WriteRegister(address uint8, register uint8, data []byte) error

WriteRegister transmits first the register and then the data to the peripheral device.

Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily write to such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.

type I2CConfig

type I2CConfig struct {
	Frequency	uint32
	SCL		Pin
	SDA		Pin

I2CConfig is used to store config info for I2C.

type IADDescriptor

type IADDescriptor struct {
	bLength			uint8	// 8
	bDescriptorType		uint8	// 11
	bFirstInterface		uint8
	bInterfaceCount		uint8
	bFunctionClass		uint8
	bFunctionSubClass	uint8
	bFunctionProtocol	uint8
	iFunction		uint8

IADDescriptor is an Interface Association Descriptor, which is used to bind 2 interfaces together in CDC composite device.

Standard Interface Association Descriptor: bLength, bDescriptorType, bFirstInterface, bInterfaceCount, bFunctionClass, bFunctionSubClass, bFunctionProtocol, iFunction

func (IADDescriptor) Bytes

func (d IADDescriptor) Bytes() [iadDescriptorSize]byte

Bytes returns IADDescriptor data.

type InterfaceDescriptor

type InterfaceDescriptor struct {
	bLength			uint8	// 9
	bDescriptorType		uint8	// 4
	bInterfaceNumber	uint8
	bAlternateSetting	uint8
	bNumEndpoints		uint8
	bInterfaceClass		uint8
	bInterfaceSubClass	uint8
	bInterfaceProtocol	uint8
	iInterface		uint8

InterfaceDescriptor implements the standard USB interface descriptor.

Table 9-12. Standard Interface Descriptor bLength, bDescriptorType, bInterfaceNumber, bAlternateSetting, bNumEndpoints, bInterfaceClass, bInterfaceSubClass, bInterfaceProtocol, iInterface

func (InterfaceDescriptor) Bytes

func (d InterfaceDescriptor) Bytes() [interfaceDescriptorSize]byte

Bytes returns InterfaceDescriptor data.

type MSCDescriptor

type MSCDescriptor struct {
	msc	InterfaceDescriptor
	in	EndpointDescriptor
	out	EndpointDescriptor

MSCDescriptor is not used yet.

type NullSerial

type NullSerial struct {

NullSerial is a serial version of /dev/null (or null router): it drops everything that is written to it.

func (NullSerial) Buffered

func (ns NullSerial) Buffered() int

Buffered returns how many bytes are buffered in the UART. It always returns 0 as there are no bytes to read.

func (NullSerial) Configure

func (ns NullSerial) Configure(config UARTConfig) error

Configure does nothing: the null serial has no configuration.

func (NullSerial) ReadByte

func (ns NullSerial) ReadByte() (byte, error)

ReadByte always returns an error because there aren’t any bytes to read.

func (NullSerial) Write

func (ns NullSerial) Write(p []byte) (n int, err error)

Write is a no-op: none of the data is being written and it will not return an error.

func (NullSerial) WriteByte

func (ns NullSerial) WriteByte(b byte) error

WriteByte is a no-op: the null serial doesn’t write bytes.

type PWM

type PWM struct {
	PWM	*nrf.PWM_Type

	channelValues	[4]volatile.Register16

PWM is one PWM peripheral, which consists of a counter and multiple output channels (that can be connected to actual pins). You can set the frequency using SetPeriod, but only for all the channels in this PWM peripheral at once.

func (*PWM) Channel

func (pwm *PWM) Channel(pin Pin) (uint8, error)

Channel returns a PWM channel for the given pin.

func (*PWM) Configure

func (pwm *PWM) Configure(config PWMConfig) error

Configure enables and configures this PWM. On the nRF52 series, the maximum period is around 0.26s.

func (*PWM) Set

func (pwm *PWM) Set(channel uint8, value uint32)

Set updates the channel value. This is used to control the channel duty cycle. For example, to set it to a 25% duty cycle, use:

ch.Set(ch.Top() / 4)

ch.Set(0) will set the output to low and ch.Set(ch.Top()) will set the output to high, assuming the output isn’t inverted.

func (*PWM) SetInverting

func (pwm *PWM) SetInverting(channel uint8, inverting bool)

SetInverting sets whether to invert the output of this channel. Without inverting, a 25% duty cycle would mean the output is high for 25% of the time and low for the rest. Inverting flips the output as if a NOT gate was placed at the output, meaning that the output would be 25% low and 75% high with a duty cycle of 25%.

func (*PWM) SetPeriod

func (pwm *PWM) SetPeriod(period uint64) error

SetPeriod updates the period of this PWM peripheral. To set a particular frequency, use the following formula:

period = 1e9 / frequency

If you use a period of 0, a period that works well for LEDs will be picked.

SetPeriod will not change the prescaler, but also won’t change the current value in any of the channels. This means that you may need to update the value for the particular channel.

Note that you cannot pick any arbitrary period after the PWM peripheral has been configured. If you want to switch between frequencies, pick the lowest frequency (longest period) once when calling Configure and adjust the frequency here as needed.

func (*PWM) Top

func (pwm *PWM) Top() uint32

Top returns the current counter top, for use in duty cycle calculation. It will only change with a call to Configure or SetPeriod, otherwise it is constant.

The value returned here is hardware dependent. In general, it’s best to treat it as an opaque value that can be divided by some number and passed to pwm.Set (see pwm.Set for more information).

type PWMConfig

type PWMConfig struct {
	// PWM period in nanosecond. Leaving this zero will pick a reasonable period
	// value for use with LEDs.
	// If you want to configure a frequency instead of a period, you can use the
	// following formula to calculate a period from a frequency:
	//     period = 1e9 / frequency
	Period uint64

PWMConfig allows setting some configuration while configuring a PWM peripheral. A zero PWMConfig is ready to use for simple applications such as dimming LEDs.

type Pin

type Pin uint8

Pin is a single pin on a chip, which may be connected to other hardware devices. It can either be used directly as GPIO pin or it can be used in other peripherals like ADC, I2C, etc.

func (Pin) Configure

func (p Pin) Configure(config PinConfig)

Configure this pin with the given configuration.

func (Pin) Get

func (p Pin) Get() bool

Get returns the current value of a GPIO pin when the pin is configured as an input or as an output.

func (Pin) High

func (p Pin) High()

High sets this GPIO pin to high, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to high that is not configured as an output pin.

func (Pin) Low

func (p Pin) Low()

Low sets this GPIO pin to low, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to low that is not configured as an output pin.

func (Pin) PortMaskClear

func (p Pin) PortMaskClear() (*uint32, uint32)

Return the register and mask to disable a given port. This can be used to implement bit-banged drivers.

func (Pin) PortMaskSet

func (p Pin) PortMaskSet() (*uint32, uint32)

Return the register and mask to enable a given GPIO pin. This can be used to implement bit-banged drivers.

func (Pin) Set

func (p Pin) Set(high bool)

Set the pin to high or low. Warning: only use this on an output pin!

func (Pin) SetInterrupt

func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error

SetInterrupt sets an interrupt to be executed when a particular pin changes state. The pin should already be configured as an input, including a pull up or down if no external pull is provided.

This call will replace a previously set callback on this pin. You can pass a nil func to unset the pin change interrupt. If you do so, the change parameter is ignored and can be set to any value (such as 0).

type PinChange

type PinChange uint8

type PinConfig

type PinConfig struct {
	Mode PinMode

type PinMode

type PinMode uint8

PinMode sets the direction and pull mode of the pin. For example, PinOutput sets the pin as an output and PinInputPullup sets the pin as an input with a pull-up.

type RingBuffer

type RingBuffer struct {
	rxbuffer	[bufferSize]volatile.Register8
	head		volatile.Register8
	tail		volatile.Register8

RingBuffer is ring buffer implementation inspired by post at https://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php

func (*RingBuffer) Clear

func (rb *RingBuffer) Clear()

Clear resets the head and tail pointer to zero.

func (*RingBuffer) Get

func (rb *RingBuffer) Get() (byte, bool)

Get returns a byte from the buffer. If the buffer is empty, the method will return a false as the second value.

func (*RingBuffer) Put

func (rb *RingBuffer) Put(val byte) bool

Put stores a byte in the buffer. If the buffer is already full, the method will return false.

func (*RingBuffer) Used

func (rb *RingBuffer) Used() uint8

Used returns how many bytes in buffer have been used.

type SPI

type SPI struct {
	Bus	*nrf.SPIM_Type
	buf	*[1]byte	// 1-byte buffer for the Transfer method

SPI on the NRF.

func (SPI) Configure

func (spi SPI) Configure(config SPIConfig)

Configure is intended to setup the SPI interface.

func (SPI) Transfer

func (spi SPI) Transfer(w byte) (byte, error)

Transfer writes/reads a single byte using the SPI interface.

func (SPI) Tx

func (spi SPI) Tx(w, r []byte) error

Tx handles read/write operation for SPI interface. Since SPI is a syncronous write/read interface, there must always be the same number of bytes written as bytes read. Therefore, if the number of bytes don’t match it will be padded until they fit: if len(w) > len(r) the extra bytes received will be dropped and if len(w) < len(r) extra 0 bytes will be sent.

type SPIConfig

type SPIConfig struct {
	Frequency	uint32
	SCK		Pin
	SDO		Pin
	SDI		Pin
	LSBFirst	bool
	Mode		uint8

SPIConfig is used to store config info for SPI.

type UART

type UART struct {
	Buffer *RingBuffer

UART on the NRF.

func (*UART) Buffered

func (uart *UART) Buffered() int

Buffered returns the number of bytes currently stored in the RX buffer.

func (*UART) Configure

func (uart *UART) Configure(config UARTConfig)

Configure the UART.

func (*UART) Read

func (uart *UART) Read(data []byte) (n int, err error)

Read from the RX buffer.

func (*UART) ReadByte

func (uart *UART) ReadByte() (byte, error)

ReadByte reads a single byte from the RX buffer. If there is no data in the buffer, returns an error.

func (*UART) Receive

func (uart *UART) Receive(data byte)

Receive handles adding data to the UART’s data buffer. Usually called by the IRQ handler for a machine.

func (*UART) SetBaudRate

func (uart *UART) SetBaudRate(br uint32)

SetBaudRate sets the communication speed for the UART.

func (*UART) Write

func (uart *UART) Write(data []byte) (n int, err error)

Write data to the UART.

func (*UART) WriteByte

func (uart *UART) WriteByte(c byte) error

WriteByte writes a byte of data to the UART.

type UARTConfig

type UARTConfig struct {
	BaudRate	uint32
	TX		Pin
	RX		Pin

UARTConfig is a struct with which a UART (or similar object) can be configured. The baud rate is usually respected, but TX and RX may be ignored depending on the chip and the type of object.

type UARTParity

type UARTParity int

UARTParity is the parity setting to be used for UART communication.


type USBCDC struct {
	Buffer			*RingBuffer
	interrupt		interrupt.Interrupt
	initcomplete		bool
	TxIdx			volatile.Register8
	waitTxc			bool
	waitTxcRetryCount	uint8
	sent			bool

USBCDC is the USB CDC aka serial over USB interface on the nRF52840

func (*USBCDC) Buffered

func (usbcdc *USBCDC) Buffered() int

Buffered returns the number of bytes currently stored in the RX buffer.

func (*USBCDC) Configure

func (usbcdc *USBCDC) Configure(config UARTConfig)

Configure the USB CDC interface. The config is here for compatibility with the UART interface.

func (*USBCDC) DTR

func (usbcdc *USBCDC) DTR() bool

func (*USBCDC) Flush

func (usbcdc *USBCDC) Flush() error

Flush flushes buffered data.

func (*USBCDC) RTS

func (usbcdc *USBCDC) RTS() bool

func (*USBCDC) Read

func (usbcdc *USBCDC) Read(data []byte) (n int, err error)

Read from the RX buffer.

func (*USBCDC) ReadByte

func (usbcdc *USBCDC) ReadByte() (byte, error)

ReadByte reads a single byte from the RX buffer. If there is no data in the buffer, returns an error.

func (*USBCDC) Receive

func (usbcdc *USBCDC) Receive(data byte)

Receive handles adding data to the UART’s data buffer. Usually called by the IRQ handler for a machine.

func (*USBCDC) Write

func (usbcdc *USBCDC) Write(data []byte) (n int, err error)

Write data to the USBCDC.

func (*USBCDC) WriteByte

func (usbcdc *USBCDC) WriteByte(c byte) error

WriteByte writes a byte of data to the USB CDC interface.