nucleo-f103rb

Constants

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
)
const (
	LED		= LED_BUILTIN
	LED_BUILTIN	= LED_GREEN
	LED_GREEN	= PA5
)
const (
	BUTTON		= BUTTON_USER
	BUTTON_USER	= PC13
)
const (
	UART_TX_PIN	= PA2
	UART_RX_PIN	= PA3
	UART_ALT_TX_PIN	= PD5
	UART_ALT_RX_PIN	= PD6
)

UART pins

const (
	SPI0_SCK_PIN	= PA5
	SPI0_MISO_PIN	= PA6
	SPI0_MOSI_PIN	= PA7
)

SPI pins

const (
	SCL_PIN	= PB6
	SDA_PIN	= PB7
)

I2C 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.

const NoPin = Pin(-1)

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 CPU_FREQUENCY = 72000000
const (
	PinInput	PinMode	= 0	// Input mode
	PinOutput10MHz	PinMode	= 1	// Output mode, max speed 10MHz
	PinOutput2MHz	PinMode	= 2	// Output mode, max speed 2MHz
	PinOutput50MHz	PinMode	= 3	// Output mode, max speed 50MHz
	PinOutput	PinMode	= PinOutput2MHz

	PinInputModeAnalog	PinMode	= 0	// Input analog mode
	PinInputModeFloating	PinMode	= 4	// Input floating mode
	PinInputModePullUpDown	PinMode	= 8	// Input pull up/down mode
	PinInputModeReserved	PinMode	= 12	// Input mode (reserved)

	PinOutputModeGPPushPull		PinMode	= 0	// Output mode general purpose push/pull
	PinOutputModeGPOpenDrain	PinMode	= 4	// Output mode general purpose open drain
	PinOutputModeAltPushPull	PinMode	= 8	// Output mode alt. purpose push/pull
	PinOutputModeAltOpenDrain	PinMode	= 12	// Output mode alt. purpose open drain
)

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.
	// Both UART0 and UART1 refer to USART2.
	UART0	= UART{
		Buffer:	NewRingBuffer(),
		Bus:	stm32.USART2,
		IRQVal:	stm32.IRQ_USART2,
	}
	UART2	= &UART0
)
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")
)
var (
	SPI1	= SPI{Bus: stm32.SPI1}
	SPI0	= SPI1
)

There are 3 SPI interfaces on the STM32F103xx. Since the first interface is named SPI1, both SPI0 and SPI1 refer to SPI1. TODO: implement SPI2 and SPI3.

var (
	I2C1	= I2C{Bus: stm32.I2C1}
	I2C0	= I2C1
)

There are 2 I2C interfaces on the STM32F103xx. Since the first interface is named I2C1, both I2C0 and I2C1 refer to I2C1. TODO: implement I2C2.

var (
	ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
)

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

type ADC

type ADC struct {
	Pin Pin
}

type I2C

type I2C struct {
	Bus *stm32.I2C_Type
}

I2C on the STM32F103xx.

func (I2C) Configure

func (i2c I2C) Configure(config I2CConfig)

Configure is intended to setup the I2C interface.

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) Tx

func (i2c I2C) Tx(addr uint16, w, r []byte) 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® bytes and stores them in r, and generates a stop condition on the bus.

func (I2C) WriteByte

func (i2c I2C) WriteByte(data byte) error

WriteByte writes a single byte to the I2C 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 {
	Frequency	uint32
	SCL		Pin
	SDA		Pin
}

I2CConfig is used to store config info for I2C.

type PWM

type PWM struct {
	Pin Pin
}

type Pin

type Pin int8

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.

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!

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

It has some limitations currently due to how “volatile” variables that are members of a struct are not compiled correctly by TinyGo. See https://github.com/tinygo-org/tinygo/issues/151 for details.

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
}

SPI on the STM32.

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
	MOSI		Pin
	MISO		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
	IRQVal	uint32
}

UART

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.

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
}