bluepill

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
    PC13    = portC + 13
    PC14    = portC + 14
    PC15    = portC + 15
)

https://wiki.stm32duino.com/index.php?title=File:Bluepillpinout.gif

const (
    LED = PC13
)

const (
    UART_TX_PIN    = PA9
    UART_RX_PIN    = PA10
    UART_ALT_TX_PIN    = PB6
    UART_ALT_RX_PIN    = PB7
)

UART pins

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

SPI pins

const (
    SDA_PIN    = PB7
    SCL_PIN    = PB6
)

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 oneof the pins in a peripheral unconfigured (if supported by the hardware).

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 (
    // USART1 is the first hardware serial port on the STM32.
    // Both UART0 and UART1 refer to USART1.
    UART0    = UART{
        Buffer:    NewRingBuffer(),
        Bus:    stm32.USART1,
    }
    UART1    = &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 CPUFrequency

func CPUFrequency() uint32

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 readoperation, and reads the response.

Many I2C-compatible devices are organized in terms of registers. This methodis a shortcut to easily read such registers. Also, it only works for deviceswith 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 theperipheral device.

Many I2C-compatible devices are organized in terms of registers. This methodis a shortcut to easily write to such registers. Also, it only works fordevices 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 hardwaredevices. It can either be used directly as GPIO pin or it can be used inother 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 outputpin. It is hardware dependent (and often undefined) what happens if you set apin 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 outputpin. It is hardware dependent (and often undefined) what happens if you set apin 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 athttps://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php

It has some limitations currently due to how “volatile” variables that aremembers 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 alreadyfull, 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/readinterface, 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 zerosuntil 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
    Interrupt    interrupt.Interrupt
}

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
}