esp32-mini32
Constants
const ( CLK= GPIO6 CMD= GPIO11 IO0= GPIO0 IO1= GPIO1 IO2= GPIO2 IO3= GPIO3 IO4= GPIO4 IO5= GPIO5 IO9= GPIO9 IO10= GPIO10 IO16= GPIO16 IO17= GPIO17 IO18= GPIO18 IO19= GPIO19 IO21= GPIO21 IO22= GPIO22 IO23= GPIO23 IO25= GPIO25 IO26= GPIO26 IO27= GPIO27 IO32= GPIO32 IO33= GPIO33 IO34= GPIO34 IO35= GPIO35 IO36= GPIO36 IO39= GPIO39 RXD= GPIO3 SD0= GPIO7 SD1= GPIO8 SD2= GPIO9 SD3= GPIO10 SVN= GPIO39 SVP= GPIO36 TCK= GPIO13 TD0= GPIO15 TDI= GPIO12 TMS= GPIO14 TXD= GPIO1 ) const LED = IO2 Built-in LED on some ESP32 boards.
const ( SPI0_SCK_PIN= IO18 SPI0_SDO_PIN= IO23 SPI0_SDI_PIN= IO19 SPI0_CS0_PIN= IO5 ) SPI pins
const ( SDA_PIN= IO21 SCL_PIN= IO22 ) I2C pins
const ( ADC0Pin= IO34 ADC1Pin= IO35 ADC2Pin= IO36 ADC3Pin= IO39 ) ADC pins
const ( UART_TX_PIN= IO1 UART_RX_PIN= IO3 ) UART0 pins
const ( UART1_TX_PIN= IO9 UART1_RX_PIN= IO10 ) UART1 pins
const ( PWM0_PINPin= IO2 PWM1_PINPin= IO0 PWM2_PINPin= IO4 ) PWM pins
const ( TWI_FREQ_100KHZ= 100000 TWI_FREQ_400KHZ= 400000 ) TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.
Deprecated: use 100 * machine.KHz or 400 * machine.KHz instead.
const ( // I2CReceive indicates target has received a message from the controller. I2CReceiveI2CTargetEvent= iota // I2CRequest indicates the controller is expecting a message from the target. I2CRequest // I2CFinish indicates the controller has ended the transaction. // // I2C controllers can chain multiple receive/request messages without // relinquishing the bus by doing 'restarts'. I2CFinish indicates the // bus has been relinquished by an I2C 'stop'. I2CFinish ) const ( // I2CModeController represents an I2C peripheral in controller mode. I2CModeControllerI2CMode= iota // I2CModeTarget represents an I2C peripheral in target mode. I2CModeTarget ) 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 PinInputPullup PinInputPulldown ) const ( GPIO0Pin= 0 GPIO1Pin= 1 GPIO2Pin= 2 GPIO3Pin= 3 GPIO4Pin= 4 GPIO5Pin= 5 GPIO6Pin= 6 GPIO7Pin= 7 GPIO8Pin= 8 GPIO9Pin= 9 GPIO10Pin= 10 GPIO11Pin= 11 GPIO12Pin= 12 GPIO13Pin= 13 GPIO14Pin= 14 GPIO15Pin= 15 GPIO16Pin= 16 GPIO17Pin= 17 GPIO18Pin= 18 GPIO19Pin= 19 GPIO21Pin= 21 GPIO22Pin= 22 GPIO23Pin= 23 GPIO25Pin= 25 GPIO26Pin= 26 GPIO27Pin= 27 GPIO32Pin= 32 GPIO33Pin= 33 GPIO34Pin= 34 GPIO35Pin= 35 GPIO36Pin= 36 GPIO37Pin= 37 GPIO38Pin= 38 GPIO39Pin= 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. 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 ( 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 ( I2C0= &I2C{Bus: esp.I2C0, funcSCL: 29, funcSDA: 30} I2C1= &I2C{Bus: esp.I2C1, funcSCL: 95, funcSDA: 96} ) 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 { 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 I2C
type I2C struct { Bus*esp.I2C_Type funcSCL, funcSDAuint32 configI2CConfig } func (*I2C) CheckDevice
func (i2c *I2C) CheckDevice(addr uint16) bool CheckDevice does an empty I2C transaction at the specified address. This can be used to find out if any device with that address is connected, e.g. for enumerating all devices on the bus.
func (*I2C) Configure
func (i2c *I2C) Configure(config I2CConfig) error func (*I2C) ReadRegister
func (i2c *I2C) ReadRegister(address uint8, register uint8, data []byte) error ReadRegister transmits the register, restarts the connection as a read operation, and reads the response.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily read such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
func (*I2C) SetBaudRate
func (i2c *I2C) SetBaudRate(br uint32) error func (*I2C) Tx
func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) Tx does a single I2C transaction at the specified address. It clocks out the given address, writes the bytes in w, reads back len(r) bytes and stores them in r, and generates a stop condition on the bus.
func (*I2C) WriteRegister
func (i2c *I2C) WriteRegister(address uint8, register uint8, data []byte) error WriteRegister transmits first the register and then the data to the peripheral device.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily write to such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
type I2CConfig
type I2CConfig struct { Frequencyuint32// in Hz SCLPin SDAPin } I2CConfig is used to store config info for I2C.
type I2CMode
type I2CMode int I2CMode determines if an I2C peripheral is in Controller or Target mode.
type I2CTargetEvent
type I2CTargetEvent uint8 I2CTargetEvent reflects events on the I2C bus
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 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 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 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 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 { Frequencyuint32 SCKPin SDOPin SDIPin LSBFirstbool Modeuint8 } 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 { 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.