const (
LED = LED_BUILTIN
LED1 = LED_GREEN
LED2 = LED_ORANGE
LED3 = LED_RED
LED4 = LED_BLUE
LED_BUILTIN = LED_GREEN
LED_GREEN = PD12
LED_ORANGE = PD13
LED_RED = PD14
LED_BLUE = PD15
)
const (
UART_TX_PIN = PA2
UART_RX_PIN = PA3
)
UART pins
const (
SPI1_SCK_PIN = PA5
SPI1_SDI_PIN = PA6
SPI1_SDO_PIN = PA7
SPI0_SCK_PIN = SPI1_SCK_PIN
SPI0_SDI_PIN = SPI1_SDI_PIN
SPI0_SDO_PIN = SPI1_SDO_PIN
)
SPI pins
const (
MEMS_ACCEL_CS = PE3
MEMS_ACCEL_INT1 = PE0
MEMS_ACCEL_INT2 = PE1
)
MEMs accelerometer
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 (
// 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
)
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
PH0 = portH + 0
PH1 = portH + 1
)
const (
Mode0 = 0
Mode1 = 1
Mode2 = 2
Mode3 = 3
)
SPI phase and polarity configs CPOL and CPHA
var (
UART0 = UART{
Buffer: NewRingBuffer(),
Bus: stm32.USART2,
AltFuncSelector: stm32.AF7_USART1_2_3,
}
UART1 = &UART0
)
var (
SPI0 = SPI{
Bus: stm32.SPI1,
AltFuncSelector: stm32.AF5_SPI1_SPI2,
}
SPI1 = &SPI0
)
Since the first interface is named SPI1, both SPI0 and SPI1 refer to SPI1. TODO: implement SPI2 and SPI3.
var (
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 (
ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
)
func CPUFrequency() uint32
func NewRingBuffer() *RingBuffer
NewRingBuffer returns a new ring buffer.
type ADC struct {
Pin Pin
}
type PWM struct {
Pin 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 (p Pin) Configure(config PinConfig)
Configure this pin with the given configuration
func (p Pin) ConfigureAltFunc(config PinConfig, altFunc stm32.AltFunc)
Configure this pin with the given configuration including alternate function mapping if necessary.
func (p Pin) Get() bool
Get returns the current value of a GPIO pin.
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 (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 (p Pin) Set(high bool)
Set the pin to high or low. Warning: only use this on an output pin!
func (p Pin) SetAltFunc(af stm32.AltFunc)
SetAltFunc maps the given alternative function to the I/O pin
type PinConfig struct {
Mode PinMode
}
type PinMode uint8
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 (rb *RingBuffer) Clear()
Clear resets the head and tail pointer to zero.
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 (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 (rb *RingBuffer) Used() uint8
Used returns how many bytes in buffer have been used.
type SPI struct {
Bus *stm32.SPI_Type
AltFuncSelector stm32.AltFunc
}
SPI on the STM32Fxxx using MODER / alternate function pins
func (spi SPI) Configure(config SPIConfig)
Configure is intended to setup the STM32 SPI1 interface. Features still TODO: - support SPI2 and SPI3 - allow setting data size to 16 bits? - allow setting direction in HW for additional optimization? - hardware SS pin?
func (spi SPI) Transfer(w byte) (byte, error)
Transfer writes/reads a single byte using the SPI interface.
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. 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 struct {
Frequency uint32
SCK Pin
SDO Pin
SDI Pin
LSBFirst bool
Mode uint8
}
SPIConfig is used to store config info for SPI.
type UART struct {
Buffer *RingBuffer
Bus *stm32.USART_Type
Interrupt interrupt.Interrupt
AltFuncSelector stm32.AltFunc
}
UART representation
func (uart UART) Buffered() int
Buffered returns the number of bytes currently stored in the RX buffer.
func (uart UART) Configure(config UARTConfig)
Configure the UART.
func (uart UART) Read(data []byte) (n int, err error)
Read from the RX buffer.
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 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 UART) SetBaudRate(br uint32)
SetBaudRate sets the communication speed for the UART. Defer to chip-specific routines for calculation
func (uart UART) Write(data []byte) (n int, err error)
Write data to the UART.
func (uart UART) WriteByte(c byte) error
WriteByte writes a byte of data to the UART.
type UARTConfig struct {
BaudRate uint32
TX Pin
RX Pin
}