nucleo-l432kc
Constants
const (
// Arduino Pins
A0 = PA0
A1 = PA1
A2 = PA3
A3 = PA4
A4 = PA5
A5 = PA6
A6 = PA7
A7 = PA2
D0 = PA10
D1 = PA9
D2 = PA12
D3 = PB0
D4 = PB7
D5 = PB6
D6 = PB1
D7 = PC14
D8 = PC15
D9 = PA8
D10 = PA11
D11 = PB5
D12 = PB4
D13 = PB3
)
const (
LED = LED_BUILTIN
LED_BUILTIN = LED_GREEN
LED_GREEN = PB3
)
const (
// This board does not have a user button, so
// use first GPIO pin by default
BUTTON = PA0
)
const (
// UART pins
// PA2 and PA15 are connected to the ST-Link Virtual Com Port (VCP)
UART_TX_PIN = PA2
UART_RX_PIN = PA15
// I2C pins
// With default solder bridge settings:
// PB6 / Arduino D5 / CN3 Pin 8 is SCL
// PB7 / Arduino D4 / CN3 Pin 7 is SDA
I2C0_SCL_PIN = PB6
I2C0_SDA_PIN = PB7
// SPI pins
SPI1_SCK_PIN = PB3
SPI1_SDI_PIN = PB5
SPI1_SDO_PIN = PB4
SPI0_SCK_PIN = SPI1_SCK_PIN
SPI0_SDI_PIN = SPI1_SDI_PIN
SPI0_SDO_PIN = SPI1_SDO_PIN
)
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.
I2CReceive I2CTargetEvent = 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.
I2CModeController I2CMode = 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 (
PinRising PinChange = 1 << iota
PinFalling
PinToggle = PinRising | PinFalling
)
const (
MAX_NBYTE_SIZE = 255
// 100ms delay = 100e6ns / 16ns
// In runtime_stm32_timers.go, tick is fixed at 16ns per tick
TIMEOUT_TICKS = 100e6 / 16
I2C_NO_STARTSTOP = 0x0
I2C_GENERATE_START_WRITE = 0x80000000 | stm32.I2C_CR2_START
I2C_GENERATE_START_READ = 0x80000000 | stm32.I2C_CR2_START | stm32.I2C_CR2_RD_WRN
I2C_GENERATE_STOP = 0x80000000 | stm32.I2C_CR2_STOP
)
const (
// WatchdogMaxTimeout in milliseconds (32.768s)
//
// Timeout is based on 12-bit counter with /256 divider on
// 32.768kHz clock. See 21.3.3 of RM0090 for table.
WatchdogMaxTimeout = ((0xfff + 1) * 256 * 1024) / 32768
)
const (
// Mode Flag
PinOutput PinMode = 0
PinInput PinMode = PinInputFloating
PinInputFloating PinMode = 1
PinInputPulldown PinMode = 2
PinInputPullup PinMode = 3
// for UART
PinModeUARTTX PinMode = 4
PinModeUARTRX PinMode = 5
// for I2C
PinModeI2CSCL PinMode = 6
PinModeI2CSDA PinMode = 7
// for SPI
PinModeSPICLK PinMode = 8
PinModeSPISDO PinMode = 9
PinModeSPISDI PinMode = 10
// for analog/ADC
PinInputAnalog PinMode = 11
// for PWM
PinModePWMOutput PinMode = 12
)
const RNG_MAX_READ_RETRIES = 1000
const PWM_MODE1 = 0x6
const (
AF0_SYSTEM = 0
AF1_TIM1_2_LPTIM1 = 1
AF2_TIM1_2 = 2
AF3_USART2 = 3
AF4_I2C1_2_3 = 4
AF5_SPI1_2 = 5
AF6_SPI3 = 6
AF7_USART1_2_3 = 7
AF8_LPUART1 = 8
AF9_CAN1_TSC = 9
AF10_USB_QUADSPI = 10
AF12_COMP1_2_SWPMI1 = 12
AF13_SAI1 = 13
AF14_TIM2_15_16_LPTIM2 = 14
AF15_EVENTOUT = 15
)
const (
PA0 = portA + 0
PA1 = portA + 1
PA2 = portA + 2
PA3 = portA + 3
PA4 = portA + 4
PA5 = portA + 5
PA6 = portA + 6
PA7 = portA + 7
PA8 = portA + 8
PA9 = portA + 9
PA10 = portA + 10
PA11 = portA + 11
PA12 = portA + 12
PA13 = portA + 13
PA14 = portA + 14
PA15 = portA + 15
PB0 = portB + 0
PB1 = portB + 1
PB2 = portB + 2
PB3 = portB + 3
PB4 = portB + 4
PB5 = portB + 5
PB6 = portB + 6
PB7 = portB + 7
PB8 = portB + 8
PB9 = portB + 9
PB10 = portB + 10
PB11 = portB + 11
PB12 = portB + 12
PB13 = portB + 13
PB14 = portB + 14
PB15 = portB + 15
PC0 = portC + 0
PC1 = portC + 1
PC2 = portC + 2
PC3 = portC + 3
PC4 = portC + 4
PC5 = portC + 5
PC6 = portC + 6
PC7 = portC + 7
PC8 = portC + 8
PC9 = portC + 9
PC10 = portC + 10
PC11 = portC + 11
PC12 = portC + 12
PC13 = portC + 13
PC14 = portC + 14
PC15 = portC + 15
PD0 = portD + 0
PD1 = portD + 1
PD2 = portD + 2
PD3 = portD + 3
PD4 = portD + 4
PD5 = portD + 5
PD6 = portD + 6
PD7 = portD + 7
PD8 = portD + 8
PD9 = portD + 9
PD10 = portD + 10
PD11 = portD + 11
PD12 = portD + 12
PD13 = portD + 13
PD14 = portD + 14
PD15 = portD + 15
PE0 = portE + 0
PE1 = portE + 1
PE2 = portE + 2
PE3 = portE + 3
PE4 = portE + 4
PE5 = portE + 5
PE6 = portE + 6
PE7 = portE + 7
PE8 = portE + 8
PE9 = portE + 9
PE10 = portE + 10
PE11 = portE + 11
PE12 = portE + 12
PE13 = portE + 13
PE14 = portE + 14
PE15 = portE + 15
)
const (
ARR_MAX = 0x10000
PSC_MAX = 0x10000
)
const APB1_TIM_FREQ = 80e6 // 80MHz
Internal use: configured speed of the APB1 and APB2 timers, this should be kept in sync with any changes to runtime package which configures the oscillators and clock frequencies
const APB2_TIM_FREQ = 80e6 // 80MHz
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 (
// USART2 is the hardware serial port connected to the onboard ST-LINK
// debugger to be exposed as virtual COM port over USB on Nucleo boards.
UART1 = &_UART1
_UART1 = UART{
Buffer: NewRingBuffer(),
Bus: stm32.USART2,
TxAltFuncSelector: 7,
RxAltFuncSelector: 3,
}
DefaultUART = UART1
// I2C1 is documented, alias to I2C0 as well
I2C1 = &I2C{
Bus: stm32.I2C1,
AltFuncSelector: 4,
}
I2C0 = I2C1
// SPI1 is documented, alias to SPI0 as well
SPI1 = &SPI{
Bus: stm32.SPI1,
AltFuncSelector: 5,
}
SPI0 = SPI1
)
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 Flash flashBlockDevice
var (
Watchdog = &watchdogImpl{}
)
var (
TIM1 = TIM{
EnableRegister: &stm32.RCC.APB2ENR,
EnableFlag: stm32.RCC_APB2ENR_TIM1EN,
Device: stm32.TIM1,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{
{PA8, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA9, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA10, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA11, AF1_TIM1_2_LPTIM1},
}},
},
busFreq: APB2_TIM_FREQ,
}
TIM2 = TIM{
EnableRegister: &stm32.RCC.APB1ENR1,
EnableFlag: stm32.RCC_APB1ENR1_TIM2EN,
Device: stm32.TIM2,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{
{PA0, AF1_TIM1_2_LPTIM1},
{PA5, AF1_TIM1_2_LPTIM1},
{PA15, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA1, AF1_TIM1_2_LPTIM1},
{PB3, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA2, AF1_TIM1_2_LPTIM1},
}},
TimerChannel{Pins: []PinFunction{
{PA3, AF1_TIM1_2_LPTIM1},
}},
},
busFreq: APB1_TIM_FREQ,
}
TIM3 = TIM{
EnableRegister: &stm32.RCC.APB1ENR1,
EnableFlag: stm32.RCC_APB1ENR1_TIM3EN,
Device: stm32.TIM3,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
},
busFreq: APB1_TIM_FREQ,
}
TIM6 = TIM{
EnableRegister: &stm32.RCC.APB1ENR1,
EnableFlag: stm32.RCC_APB1ENR1_TIM6EN,
Device: stm32.TIM6,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
},
busFreq: APB1_TIM_FREQ,
}
TIM7 = TIM{
EnableRegister: &stm32.RCC.APB1ENR1,
EnableFlag: stm32.RCC_APB1ENR1_TIM7EN,
Device: stm32.TIM7,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
},
busFreq: APB1_TIM_FREQ,
}
TIM15 = TIM{
EnableRegister: &stm32.RCC.APB2ENR,
EnableFlag: stm32.RCC_APB2ENR_TIM15EN,
Device: stm32.TIM15,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{
{PA2, AF14_TIM2_15_16_LPTIM2},
}},
TimerChannel{Pins: []PinFunction{
{PA3, AF14_TIM2_15_16_LPTIM2},
}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
},
busFreq: APB2_TIM_FREQ,
}
TIM16 = TIM{
EnableRegister: &stm32.RCC.APB2ENR,
EnableFlag: stm32.RCC_APB2ENR_TIM16EN,
Device: stm32.TIM16,
Channels: [4]TimerChannel{
TimerChannel{Pins: []PinFunction{
{PA6, AF14_TIM2_15_16_LPTIM2},
}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
TimerChannel{Pins: []PinFunction{}},
},
busFreq: APB2_TIM_FREQ,
}
)
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
func CPUReset
func CPUReset()
CPUReset performs a hard system reset.
func DeviceID
func DeviceID() []byte
DeviceID returns an identifier that is unique within a particular chipset.
The identity is one burnt into the MCU itself.
The length of the device ID for STM32 is 12 bytes (96 bits).
func FlashDataEnd
func FlashDataEnd() uintptr
Return the end of the writable flash area. Usually this is the address one past the end of the on-chip flash.
func FlashDataStart
func FlashDataStart() uintptr
Return the start of the writable flash area, aligned on a page boundary. This is usually just after the program and static data.
func GetRNG
func GetRNG() (uint32, error)
GetRNG returns 32 bits of cryptographically secure random data
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 BlockDevice
type BlockDevice interface {
// ReadAt reads the given number of bytes from the block device.
io.ReaderAt
// WriteAt writes the given number of bytes to the block device.
io.WriterAt
// Size returns the number of bytes in this block device.
Size() int64
// WriteBlockSize returns the block size in which data can be written to
// memory. It can be used by a client to optimize writes, non-aligned writes
// should always work correctly.
WriteBlockSize() int64
// EraseBlockSize returns the smallest erasable area on this particular chip
// in bytes. This is used for the block size in EraseBlocks.
// It must be a power of two, and may be as small as 1. A typical size is 4096.
EraseBlockSize() int64
// EraseBlocks erases the given number of blocks. An implementation may
// transparently coalesce ranges of blocks into larger bundles if the chip
// supports this. The start and len parameters are in block numbers, use
// EraseBlockSize to map addresses to blocks.
EraseBlocks(start, len int64) error
}
BlockDevice is the raw device that is meant to store flash data.
type ChannelCallback
type ChannelCallback func(channel uint8)
type I2C
type I2C struct {
Bus *stm32.I2C_Type
AltFuncSelector uint8
}
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
SetBaudRate sets the communication speed for I2C.
func (*I2C) Tx
func (i2c *I2C) Tx(addr uint16, w, r []byte) error
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 {
Frequency uint32
SCL Pin
SDA Pin
}
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 {
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) ConfigureAltFunc
func (p Pin) ConfigureAltFunc(config PinConfig, altFunc uint8)
Configure this pin with the given configuration including alternate
function mapping if necessary.
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)
PortMaskClear returns the register and mask to disable a given port. This can be used to implement bit-banged drivers.
func (Pin) PortMaskSet
func (p Pin) PortMaskSet() (*uint32, uint32)
PortMaskSet returns the register and mask to enable a given GPIO pin. This can be used to implement bit-banged drivers.
func (Pin) Set
func (p Pin) Set(high bool)
Set the pin to high or low. Warning: only use this on an output pin!
func (Pin) SetAltFunc
func (p Pin) SetAltFunc(af uint8)
SetAltFunc maps the given alternative function to the I/O pin
func (Pin) SetInterrupt
func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) 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.
This call will replace a previously set callback on this pin. 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).
type PinChange
type PinChange uint8
———- General pin operations ———-
type PinConfig
type PinConfig struct {
Mode PinMode
}
type PinFunction
type PinFunction struct {
Pin Pin
AltFunc uint8
}
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 *stm32.SPI_Type
AltFuncSelector uint8
}
SPI on the STM32Fxxx using MODER / alternate function pins
func (SPI) Configure
func (spi SPI) Configure(config SPIConfig) error
Configure is intended to setup the STM32 SPI1 interface.
func (SPI) Transfer
func (spi SPI) Transfer(w byte) (byte, error)
Transfer writes/reads a single byte using the SPI interface.
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. 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
type SPIConfig struct {
Frequency uint32
SCK Pin
SDO Pin
SDI Pin
LSBFirst bool
Mode uint8
}
SPIConfig is used to store config info for SPI.
type TIM
type TIM struct {
EnableRegister *volatile.Register32
EnableFlag uint32
Device *stm32.TIM_Type
Channels [4]TimerChannel
UpInterrupt interrupt.Interrupt
OCInterrupt interrupt.Interrupt
wraparoundCallback TimerCallback
channelCallbacks [4]ChannelCallback
busFreq uint64
}
func (*TIM) Channel
func (t *TIM) Channel(pin Pin) (uint8, error)
Channel returns a PWM channel for the given pin.
func (*TIM) Configure
func (t *TIM) Configure(config PWMConfig) error
Configure enables and configures this PWM.
func (*TIM) Count
func (t *TIM) Count() uint32
func (*TIM) Set
func (t *TIM) Set(channel uint8, value uint32)
Set updates the channel value. This is used to control the channel duty cycle. For example, to set it to a 25% duty cycle, use:
t.Set(ch, t.Top() / 4)
ch.Set(0) will set the output to low and ch.Set(ch.Top()) will set the output to high, assuming the output isn’t inverted.
func (*TIM) SetInverting
func (t *TIM) SetInverting(channel uint8, inverting bool)
SetInverting sets whether to invert the output of this channel. Without inverting, a 25% duty cycle would mean the output is high for 25% of the time and low for the rest. Inverting flips the output as if a NOT gate was placed at the output, meaning that the output would be 25% low and 75% high with a duty cycle of 25%.
func (*TIM) SetMatchInterrupt
func (t *TIM) SetMatchInterrupt(channel uint8, callback ChannelCallback) error
Sets a callback to be called when a channel reaches it’s set-point.
For example, if t.Set(ch, t.Top() / 4) is used then the callback will
be called every quarter-period of the timer’s base Period.
func (*TIM) SetPeriod
func (t *TIM) SetPeriod(period uint64) error
SetPeriod updates the period of this PWM peripheral. To set a particular frequency, use the following formula:
period = 1e9 / frequency
If you use a period of 0, a period that works well for LEDs will be picked.
SetPeriod will not change the prescaler, but also won’t change the current value in any of the channels. This means that you may need to update the value for the particular channel.
Note that you cannot pick any arbitrary period after the PWM peripheral has been configured. If you want to switch between frequencies, pick the lowest frequency (longest period) once when calling Configure and adjust the frequency here as needed.
func (*TIM) SetWraparoundInterrupt
func (t *TIM) SetWraparoundInterrupt(callback TimerCallback) error
SetWraparoundInterrupt configures a callback to be called each time the timer ‘wraps-around’.
For example, if Configure(PWMConfig{Period:1000000}) is used,
to set the timer period to 1ms, this callback will be called every
1ms.
func (*TIM) Top
func (t *TIM) Top() uint32
Top returns the current counter top, for use in duty cycle calculation. It will only change with a call to Configure or SetPeriod, otherwise it is constant.
The value returned here is hardware dependent. In general, it’s best to treat it as an opaque value that can be divided by some number and passed to pwm.Set (see pwm.Set for more information).
func (*TIM) Unset
func (t *TIM) Unset(channel uint8)
Unset disables a channel, including any configured interrupts.
type TimerCallback
type TimerCallback func()
type TimerChannel
type TimerChannel struct {
Pins []PinFunction
}
type UART
type UART struct {
Buffer *RingBuffer
Bus *stm32.USART_Type
Interrupt interrupt.Interrupt
TxAltFuncSelector uint8
RxAltFuncSelector uint8
// Registers specific to the chip
rxReg *volatile.Register32
txReg *volatile.Register32
statusReg *volatile.Register32
txEmptyFlag uint32
}
UART representation
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.
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(br uint32)
SetBaudRate sets the communication speed for the UART. Defer to chip-specific routines for calculation
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 WatchdogConfig
type WatchdogConfig struct {
// The timeout (in milliseconds) before the watchdog fires.
//
// If the requested timeout exceeds `MaxTimeout` it will be rounded
// down.
TimeoutMillis uint32
}
WatchdogConfig holds configuration for the watchdog timer.