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 = iota
PinOutput
PinInputPullup
PinInputPulldown
)
const (
Mode0 = 0
Mode1 = 1
Mode2 = 2
Mode3 = 3
)
SPI phase and polarity configs CPOL and CPHA
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 (
SPI0 = SPI{0}
I2C0 = I2C{0}
UART0 = UART{0}
)
var (
ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
)
func InitADC()
InitADC enables support for ADC peripherals.
func InitPWM()
InitPWM enables support for PWM peripherals.
func NewRingBuffer() *RingBuffer
NewRingBuffer returns a new ring buffer.
type ADC struct {
Pin Pin
}
func (adc ADC) Configure()
Configure configures an ADC pin to be able to be used to read data.
func (adc ADC) Get() uint16
Get reads the current analog value from this ADC peripheral.
type I2C struct {
Bus uint8
}
I2C is a generic implementation of the Inter-IC communication protocol.
func (i2c I2C) Configure(config I2CConfig)
Configure is intended to setup the I2C interface.
func (i2c I2C) Tx(addr uint16, w, r []byte) error
Tx does a single I2C transaction at the specified address.
type I2CConfig struct {
Frequency uint32
SCL Pin
SDA Pin
}
I2CConfig is used to store config info for I2C.
type PWM struct {
Pin Pin
}
func (pwm PWM) Configure() error
Configure configures a PWM pin for output.
func (pwm PWM) Set(value uint16)
Set turns on the duty cycle for a PWM pin using the provided value.
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 (p Pin) Configure(config PinConfig)
func (p Pin) Get() bool
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 (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 (p Pin) Set(value bool)
type PinConfig struct {
Mode PinMode
}
type PinMode uint8
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 (rb *RingBuffer) Clear()
Clear resets the head and tail pointer to zero.
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 (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 (rb *RingBuffer) Used() uint8
Used returns how many bytes in buffer have been used.
type SPI struct {
Bus uint8
}
func (spi SPI) Configure(config SPIConfig)
func (spi SPI) Transfer(w byte) (byte, error)
Transfer writes/reads a single byte using the SPI interface.
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. The Tx method knows about this, and offers a few different ways of calling it.
This form sends the bytes in tx buffer, putting the resulting bytes read into the rx buffer. Note that the tx and rx buffers must be the same size:
spi.Tx(tx, rx)
This form sends the tx buffer, ignoring the result. Useful for sending “commands” that return zeros until all the bytes in the command packet have been received:
spi.Tx(tx, nil)
This form sends zeros, putting the result into the rx buffer. Good for reading a “result packet”:
spi.Tx(nil, rx)
type SPIConfig struct {
Frequency uint32
SCK Pin
SDO Pin
SDI Pin
Mode uint8
}
type UART struct {
Bus uint8
}
func (uart UART) Buffered() int
Buffered returns the number of bytes currently stored in the RX buffer.
func (uart UART) Configure(config UARTConfig)
Configure the UART.
func (uart UART) Read(data []byte) (n int, err error)
Read from the UART.
func (uart UART) ReadByte() (byte, error)
ReadByte reads a single byte from the UART.
func (uart UART) Write(data []byte) (n int, err error)
Write to the UART.
func (uart UART) WriteByte(b byte) error
WriteByte writes a single byte to the UART.
type UARTConfig struct {
BaudRate uint32
TX Pin
RX Pin
}