m5stamp-c3
Constants
const (
IO0 = GPIO0
IO1 = GPIO1
IO2 = GPIO2
IO3 = GPIO3
IO4 = GPIO4
IO5 = GPIO5
IO6 = GPIO6
IO7 = GPIO7
IO8 = GPIO8
IO9 = GPIO9
IO10 = GPIO10
IO11 = GPIO11
IO12 = GPIO12
IO13 = GPIO13
IO14 = GPIO14
IO15 = GPIO15
IO16 = GPIO16
IO17 = GPIO17
IO18 = GPIO18
IO19 = GPIO19
IO20 = GPIO20
IO21 = GPIO21
XTAL_32K_P = IO0
XTAL_32K_N = IO1
MTMS = IO4
MTDI = IO5
MTCK = IO6
MTDO = IO7
VDD_SPI = IO11
SPIHD = IO12
SPISP = IO13
SPICS0 = IO14
SPICLK = IO15
SPID = IO16
SPIQ = IO17
U0RXD = IO20
U0TXD = IO21
UART_TX_PIN = U0TXD
UART_RX_PIN = U0RXD
)
const (
WS2812 = IO2
)
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 (
PinOutput PinMode = iota
PinInput
PinInputPullup
PinInputPulldown
)
const (
GPIO0 Pin = 0
GPIO1 Pin = 1
GPIO2 Pin = 2
GPIO3 Pin = 3
GPIO4 Pin = 4
GPIO5 Pin = 5
GPIO6 Pin = 6
GPIO7 Pin = 7
GPIO8 Pin = 8
GPIO9 Pin = 9
GPIO10 Pin = 10
GPIO11 Pin = 11
GPIO12 Pin = 12
GPIO13 Pin = 13
GPIO14 Pin = 14
GPIO15 Pin = 15
GPIO16 Pin = 16
GPIO17 Pin = 17
GPIO18 Pin = 18
GPIO19 Pin = 19
GPIO20 Pin = 20
GPIO21 Pin = 21
)
const (
PinRising PinChange = iota + 1
PinFalling
PinToggle
)
Pin change interrupt constants for SetInterrupt.
const (
SPI_MODE0 = uint8(0)
SPI_MODE1 = uint8(1)
SPI_MODE2 = uint8(2)
SPI_MODE3 = uint8(3)
FSPICLK_IN_IDX = uint32(63)
FSPICLK_OUT_IDX = uint32(63)
FSPIQ_IN_IDX = uint32(64)
FSPIQ_OUT_IDX = uint32(64)
FSPID_IN_IDX = uint32(65)
FSPID_OUT_IDX = uint32(65)
FSPIHD_IN_IDX = uint32(66)
FSPIHD_OUT_IDX = uint32(66)
FSPIWP_IN_IDX = uint32(67)
FSPIWP_OUT_IDX = uint32(67)
FSPICS0_IN_IDX = uint32(68)
FSPICS0_OUT_IDX = uint32(68)
FSPICS1_OUT_IDX = uint32(69)
FSPICS2_OUT_IDX = uint32(70)
FSPICS3_OUT_IDX = uint32(71)
FSPICS4_OUT_IDX = uint32(72)
FSPICS5_OUT_IDX = uint32(73)
)
const (
// ParityNone means to not use any parity checking. This is
// the most common setting.
ParityNone UARTParity = 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
UART0 = &_UART0
_UART0 = UART{Bus: esp.UART0, Buffer: NewRingBuffer()}
UART1 = &_UART1
_UART1 = UART{Bus: esp.UART1, Buffer: NewRingBuffer()}
onceUart = sync.Once{}
errSamePins = errors.New("UART: invalid pin combination")
errWrongUART = errors.New("UART: unsupported UARTn")
errWrongBitSize = errors.New("UART: invalid data size")
errWrongStopBitSize = errors.New("UART: invalid bit size")
)
var (
_USBCDC = &USB_DEVICE{
Bus: esp.USB_DEVICE,
}
USBCDC Serialer = _USBCDC
)
var (
ErrInvalidSPIBus = errors.New("machine: SPI bus is invalid")
ErrInvalidSPIMode = errors.New("machine: SPI mode is invalid")
)
var (
// SPI0 and SPI1 are reserved for use by the caching system etc.
SPI2 = &SPI{esp.SPI2}
)
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
CPUFrequency returns the current CPU frequency of the chip. Currently it is a fixed frequency but it may allow changing in the future.
func GetRNG
func GetRNG() (ret uint32, err error)
GetRNG returns 32-bit random numbers using the ESP32-C3 true random number generator, Random numbers are generated based on the thermal noise in the system and the asynchronous clock mismatch. For maximum entropy also make sure that the SAR_ADC is enabled. See esp32-c3_technical_reference_manual_en.pdf p.524
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 {
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)
SampleTime uint32 // 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 {
Stereo bool
DIN Pin
CLK Pin
}
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 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 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)) (err 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.
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). If the pin is already configured with a callback, you must first unset this pins interrupt before you can set a new callback.
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 *esp.SPI2_Type
}
Serial Peripheral Interface on the ESP32-C3.
func (*SPI) Configure
func (spi *SPI) Configure(config SPIConfig) error
Configure and make the SPI peripheral ready to use.
func (*SPI) Transfer
func (spi *SPI) Transfer(w byte) (byte, error)
Transfer writes/reads a single byte using the SPI interface. If you need to transfer larger amounts of data, Tx will be faster.
func (*SPI) Tx
func (spi *SPI) Tx(w, r []byte) error
Tx handles read/write operation for SPI interface. Since SPI is a synchronous write/read interface, there must always be the same number of bytes written as bytes read. This is accomplished by sending zero bits if r is bigger than w or discarding the incoming data if w is bigger than r.
type SPIConfig
type SPIConfig struct {
Frequency uint32
SCK Pin // Serial Clock
SDO Pin // Serial Data Out (MOSI)
SDI Pin // Serial Data In (MISO)
CS Pin // Chip Select (optional)
LSBFirst bool // MSB is default
Mode uint8 // SPI_MODE0 is default
}
SPIConfig is used to store config info for SPI.
type Serialer
type Serialer interface {
WriteByte(c byte) error
Write(data []byte) (n int, err error)
Configure(config UARTConfig) error
Buffered() int
ReadByte() (byte, error)
DTR() bool
RTS() bool
}
type UART
type UART struct {
Bus *esp.UART_Type
Buffer *RingBuffer
ParityErrorDetected bool // set when parity error detected
DataErrorDetected bool // set when data corruption detected
DataOverflowDetected bool // set when data overflow detected in UART FIFO buffer or 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) error
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(baudRate uint32)
func (*UART) SetFormat
func (uart *UART) SetFormat(dataBits, stopBits int, parity UARTParity) error
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 {
BaudRate uint32
TX Pin
RX Pin
RTS Pin
CTS 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 uint8
UARTParity is the parity setting to be used for UART communication.
type USB_DEVICE
type USB_DEVICE struct {
Bus *esp.USB_DEVICE_Type
}
USB Serial/JTAG Controller See esp32-c3_technical_reference_manual_en.pdf pg. 736
func (*USB_DEVICE) Buffered
func (usbdev *USB_DEVICE) Buffered() int
func (*USB_DEVICE) Configure
func (usbdev *USB_DEVICE) Configure(config UARTConfig) error
func (*USB_DEVICE) DTR
func (usbdev *USB_DEVICE) DTR() bool
func (*USB_DEVICE) RTS
func (usbdev *USB_DEVICE) RTS() bool
func (*USB_DEVICE) ReadByte
func (usbdev *USB_DEVICE) ReadByte() (byte, error)
func (*USB_DEVICE) Write
func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error)
func (*USB_DEVICE) WriteByte
func (usbdev *USB_DEVICE) WriteByte(c byte) error