machine

Documentation

Index

• Constants
• Variables
• type ADC
• type ADCConfig
• type NullSerial
  • func (ns NullSerial) Buffered() int
  • func (ns NullSerial) Configure(config UARTConfig) error
  • func (ns NullSerial) ReadByte() (byte, error)
  • func (ns NullSerial) Write(p []byte) (n int, err error)
  • func (ns NullSerial) WriteByte(b byte) error
• type PWMConfig
• type Pin
  • func (p Pin) High()
  • func (p Pin) Low()
• type PinConfig
• type PinMode
• type RingBuffer
  • func NewRingBuffer() *RingBuffer
  • func (rb *RingBuffer) Clear()
  • func (rb *RingBuffer) Get() (byte, bool)
  • func (rb *RingBuffer) Put(val byte) bool
  • func (rb *RingBuffer) Used() uint8
• type UARTConfig

Constants

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).

Variables

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

Types

type ADC

type ADC struct {
	Pin Pin
}

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 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 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) 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.

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 {
	// contains filtered or unexported fields
}

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

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

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 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.