m5stack-core2
Constants
const (
IO0 = GPIO0
IO1 = GPIO1 // U0TXD
IO2 = GPIO2
IO3 = GPIO3 // U0RXD
IO4 = GPIO4
IO5 = GPIO5
IO6 = GPIO6 // SD_CLK
IO7 = GPIO7 // SD_DATA0
IO8 = GPIO8 // SD_DATA1
IO9 = GPIO9 // SD_DATA2
IO10 = GPIO10 // SD_DATA3
IO11 = GPIO11 // SD_CMD
IO12 = GPIO12
IO13 = GPIO13 // U0RXD
IO14 = GPIO14 // U1TXD
IO15 = GPIO15
IO16 = GPIO16
IO17 = GPIO17
IO18 = GPIO18 // SPI0_SCK
IO19 = GPIO19
IO21 = GPIO21 // SDA0
IO22 = GPIO22 // SCL0
IO23 = GPIO23 // SPI0_SDO
IO25 = GPIO25
IO26 = GPIO26
IO27 = GPIO27
IO32 = GPIO32 // SDA1
IO33 = GPIO33 // SCL1
IO34 = GPIO34
IO35 = GPIO35 // ADC1
IO36 = GPIO36 // ADC2
IO38 = GPIO38 // SPI0_SDI
IO39 = GPIO39
)
const (
SPI0_SCK_PIN = IO18
SPI0_SDO_PIN = IO23
SPI0_SDI_PIN = IO38
SPI0_CS0_PIN = IO5
// LCD (ILI9342C)
LCD_SCK_PIN = SPI0_SCK_PIN
LCD_SDO_PIN = SPI0_SDO_PIN
LCD_SDI_PIN = SPI0_SDI_PIN
LCD_SS_PIN = SPI0_CS0_PIN
LCD_DC_PIN = IO15
// SD CARD
SDCARD_SCK_PIN = SPI0_SCK_PIN
SDCARD_SDO_PIN = SPI0_SDO_PIN
SDCARD_SDI_PIN = SPI0_SDI_PIN
SDCARD_SS_PIN = IO4
)
SPI pins
const (
// Internal I2C (AXP192 / FT6336U / BM8563 / MPU6886)
SDA0_PIN = IO21
SCL0_PIN = IO22
// External I2C (PORT A)
SDA1_PIN = IO32
SCL1_PIN = IO33
SDA_PIN = SDA1_PIN
SCL_PIN = SCL1_PIN
)
I2C pins
const (
ADC1 Pin = IO35
ADC2 Pin = IO36
)
ADC pins
const (
DAC1 Pin = IO25
DAC2 Pin = IO26
)
DAC pins
const (
// UART0 (CP2104)
UART0_TX_PIN = IO1
UART0_RX_PIN = IO3
UART1_TX_PIN = IO14
UART1_RX_PIN = IO13
UART_TX_PIN = UART0_TX_PIN
UART_RX_PIN = UART0_RX_PIN
)
UART 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 (
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
GPIO21 Pin = 21
GPIO22 Pin = 22
GPIO23 Pin = 23
GPIO25 Pin = 25
GPIO26 Pin = 26
GPIO27 Pin = 27
GPIO32 Pin = 32
GPIO33 Pin = 33
GPIO34 Pin = 34
GPIO35 Pin = 35
GPIO36 Pin = 36
GPIO37 Pin = 37
GPIO38 Pin = 38
GPIO39 Pin = 39
)
Hardware pin numbers
const (
Mode0 = 0
Mode1 = 1
Mode2 = 2
Mode3 = 3
)
SPI phase and polarity configs CPOL and CPHA
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 (
ErrInvalidSPIBus = errors.New("machine: invalid SPI bus")
)
var DefaultUART = UART0
var (
UART0 = &_UART0
_UART0 = UART{Bus: esp.UART0, Buffer: NewRingBuffer()}
UART1 = &_UART1
_UART1 = UART{Bus: esp.UART1, Buffer: NewRingBuffer()}
UART2 = &_UART2
_UART2 = UART{Bus: esp.UART2, Buffer: NewRingBuffer()}
)
var (
// SPI0 and SPI1 are reserved for use by the caching system etc.
SPI2 = SPI{esp.SPI2}
SPI3 = SPI{esp.SPI3}
)
var (
ErrPWMPeriodTooLong = errors.New("pwm: period too long")
)
var Serial = DefaultUART
Serial is implemented via the default (usually the first) UART on the chip.
var (
ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
errSPIInvalidMachineConfig = errors.New("SPI port was not configured properly by the machine")
)
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 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 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 the pin to high or low. Warning: only use this on 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 {
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.SPI_Type
}
Serial Peripheral Interface on the ESP32.
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 syncronous 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
SDO Pin
SDI Pin
LSBFirst bool
Mode uint8
}
SPIConfig configures a SPI peripheral on the ESP32. Make sure to set at least SCK, SDO and SDI (possibly to NoPin if not in use). The default for LSBFirst (false) and Mode (0) are good for most applications. The frequency defaults to 1MHz if not set but can be configured up to 40MHz. Possible values are 40MHz and integer divisions from 40MHz such as 20MHz, 13.3MHz, 10MHz, 8MHz, etc.
type UART
type UART struct {
Bus *esp.UART_Type
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)
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 {
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.