stm32f4disco

Constants

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

Variables

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

func CPUFrequency() uint32

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

type ADC

type ADC struct {
	Pin Pin
}

type PWM

type PWM struct {
	Pin Pin
}

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 stm32.AltFunc)

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.

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) 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 stm32.AltFunc)

SetAltFunc maps the given alternative function to the I/O pin

type PinConfig

type PinConfig struct {
	Mode PinMode
}

type PinMode

type PinMode uint8

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	stm32.AltFunc
}

SPI on the STM32Fxxx using MODER / alternate function pins

func (SPI) Configure

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) 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 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

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

type UART struct {
	Buffer		*RingBuffer
	Bus		*stm32.USART_Type
	Interrupt	interrupt.Interrupt
	AltFuncSelector	stm32.AltFunc
}

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 to the UART.

func (UART) WriteByte

func (uart UART) WriteByte(c byte) error

WriteByte writes a byte of data to the UART.

type UARTConfig

type UARTConfig struct {
	BaudRate	uint32
	TX		Pin
	RX		Pin
}