nodemcu
Constants
const ( D0= GPIO16 D1= GPIO5 D2= GPIO4 D3= GPIO0 D4= GPIO2 D5= GPIO14 D6= GPIO12 D7= GPIO13 D8= GPIO15 ) GPIO pins on the NodeMCU board.
const LED = D4 Onboard blue LED (on the AI-Thinker module).
const ( SPI0_SCK_PIN= D5 SPI0_SDO_PIN= D7 SPI0_SDI_PIN= D6 SPI0_CS0_PIN= D8 ) SPI pins
const ( SDA_PIN= D2 SCL_PIN= D1 ) I2C pins
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 ( KHz= 1000 MHz= 1000_000 GHz= 1000_000_000 ) Generic 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).
const ( PinOutputPinMode= iota PinInput ) const ( GPIO0Pin= iota GPIO1 GPIO2 GPIO3 GPIO4 GPIO5 GPIO6 GPIO7 GPIO8 GPIO9 GPIO10 GPIO11 GPIO12 GPIO13 GPIO14 GPIO15 GPIO16 ) Hardware pin numbers
const ( UART_TX_PINPin= 1 UART_RX_PINPin= 3 ) Pins that are fixed by the chip.
const ( // ParityNone means to not use any parity checking. This is // the most common setting. ParityNoneUARTParity= iota // ParityEven means to expect that the total number of 1 bits sent // should be an even number. ParityEven // ParityOdd means to expect that the total number of 1 bits sent // should be an odd number. ParityOdd ) Variables
var ( ErrTimeoutRNG= errors.New("machine: RNG Timeout") ErrClockRNG= errors.New("machine: RNG Clock Error") ErrSeedRNG= errors.New("machine: RNG Seed Error") 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 DefaultUART = UART0 var UART0 = &_UART0 UART0 is a hardware UART that supports both TX and RX.
var ( ErrPWMPeriodTooLong = errors.New("pwm: period too long") ) var Serial = DefaultUART Serial is implemented via the default (usually the first) UART on the chip.
func CPUFrequency
func CPUFrequency() uint32 func InitSerial
func InitSerial() func NewRingBuffer
func NewRingBuffer() *RingBuffer NewRingBuffer returns a new ring buffer.
type ADC
type ADC struct { Pin Pin } type ADCConfig
type ADCConfig struct { Referenceuint32// analog reference voltage (AREF) in millivolts Resolutionuint32// number of bits for a single conversion (e.g., 8, 10, 12) Samplesuint32// number of samples for a single conversion (e.g., 4, 8, 16, 32) SampleTimeuint32// sample time, in microseconds (µs) } 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 PDMConfig
type PDMConfig struct { Stereobool DINPin CLKPin } 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 sets the given pin as output or input pin.
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 GPIO pin. This can be used to implement bit-banged drivers.
Warning: only use this on an output pin!
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.
Warning: only use this on an output pin!
func (Pin) Set
func (p Pin) Set(value bool) Set sets the output value of this pin to high (true) or low (false).
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 headvolatile.Register8 tailvolatile.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 UART
type UART struct { Buffer *RingBuffer } 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 baud rate. TX and RX pins are fixed by the hardware so cannot be modified and will be ignored.
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) Write
func (uart *UART) Write(data []byte) (n int, err error) Write data over the UART’s Tx. This function blocks until the data is finished being sent.
func (*UART) WriteByte
func (uart *UART) WriteByte(c byte) error WriteByte writes a byte of data over the UART’s Tx. This function blocks until the data is finished being sent.
type UARTConfig
type UARTConfig struct { BaudRateuint32 TXPin RXPin RTSPin CTSPin } 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 uint8 UARTParity is the parity setting to be used for UART communication.