feather-stm32f405

Constants

const (
	NUM_DIGITAL_IO_PINS	= 39
	NUM_ANALOG_IO_PINS	= 7
)
const (
	// Arduino pin = MCU port pin // primary functions (alternate functions)
	D0	= PB11	// USART3 RX, PWM TIM2_CH4 (I2C2 SDA)
	D1	= PB10	// USART3 TX, PWM TIM2_CH3 (I2C2 SCL, I2S2 BCK)
	D2	= PB3	// GPIO, SPI3 FLASH SCK
	D3	= PB4	// GPIO, SPI3 FLASH MISO
	D4	= PB5	// GPIO, SPI3 FLASH MOSI
	D5	= PC7	// GPIO, PWM TIM3_CH2 (USART6 RX, I2S3 MCK)
	D6	= PC6	// GPIO, PWM TIM3_CH1 (USART6 TX, I2S2 MCK)
	D7	= PA15	// GPIO, SPI3 FLASH CS
	D8	= PC0	// GPIO, Neopixel
	D9	= PB8	// GPIO, PWM TIM4_CH3 (CAN1 RX, I2C1 SCL)
	D10	= PB9	// GPIO, PWM TIM4_CH4 (CAN1 TX, I2C1 SDA, I2S2 WSL)
	D11	= PC3	// GPIO (I2S2 SD, SPI2 MOSI)
	D12	= PC2	// GPIO (I2S2ext SD, SPI2 MISO)
	D13	= PC1	// GPIO, Builtin LED
	D14	= PB7	// I2C1 SDA, PWM TIM4_CH2 (USART1 RX)
	D15	= PB6	// I2C1 SCL, PWM TIM4_CH1 (USART1 TX, CAN2 TX)
	D16	= PA4	// A0 (DAC OUT1)
	D17	= PA5	// A1 (DAC OUT2, SPI1 SCK)
	D18	= PA6	// A2, PWM TIM3_CH1 (SPI1 MISO)
	D19	= PA7	// A3, PWM TIM3_CH2 (SPI1 MOSI)
	D20	= PC4	// A4
	D21	= PC5	// A5
	D22	= PA3	// A6
	D23	= PB13	// SPI2 SCK, PWM TIM1_CH1N (I2S2 BCK, CAN2 TX)
	D24	= PB14	// SPI2 MISO, PWM TIM1_CH2N (I2S2ext SD)
	D25	= PB15	// SPI2 MOSI, PWM TIM1_CH3N (I2S2 SD)
	D26	= PC8	// SDIO
	D27	= PC9	// SDIO
	D28	= PC10	// SDIO
	D29	= PC11	// SDIO
	D30	= PC12	// SDIO
	D31	= PD2	// SDIO
	D32	= PB12	// SD Detect
	D33	= PC14	// OSC32
	D34	= PC15	// OSC32
	D35	= PA11	// USB D+
	D36	= PA12	// USB D-
	D37	= PA13	// SWDIO
	D38	= PA14	// SWCLK
)

Digital pins

const (
	A0	= D16	// ADC12 IN4
	A1	= D17	// ADC12 IN5
	A2	= D18	// ADC12 IN6
	A3	= D19	// ADC12 IN7
	A4	= D20	// ADC12 IN14
	A5	= D21	// ADC12 IN15
	A6	= D22	// VBAT
)

Analog pins

const (
	NUM_BOARD_LED		= 1
	NUM_BOARD_NEOPIXEL	= 1

	LED_RED		= D13
	LED_NEOPIXEL	= D8
	LED_BUILTIN	= LED_RED
	LED		= LED_BUILTIN
	WS2812		= D8
)
const (
	// #===========#==========#==============#============#=======#=======#
	// | Interface | Hardware |  Bus(Freq)   | RX/TX Pins | AltFn | Alias |
	// #===========#==========#==============#============#=======#=======#
	// |   UART1   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   |   ~   |
	// |   UART2   |  USART6  | APB2(84 MHz) |   D5/D6    |   8   |   ~   |
	// |   UART3   |  USART1  | APB2(84 MHz) |  D14/D15   |   7   |   ~   |
	// | --------- | -------- | ------------ | ---------- | ----- | ----- |
	// |   UART0   |  USART3  | APB1(42 MHz) |   D0/D1    |   7   | UART1 |
	// #===========#==========#==============#============#=======#=======#
	NUM_UART_INTERFACES	= 3

	UART1_RX_PIN	= D0	// UART1 = hardware: USART3
	UART1_TX_PIN	= D1	//

	UART2_RX_PIN	= D5	// UART2 = hardware: USART6
	UART2_TX_PIN	= D6	//

	UART3_RX_PIN	= D14	// UART3 = hardware: USART1
	UART3_TX_PIN	= D15	//

	UART0_RX_PIN	= UART1_RX_PIN	// UART0 = alias: UART1
	UART0_TX_PIN	= UART1_TX_PIN	//

	UART_RX_PIN	= UART0_RX_PIN	// default/primary UART pins
	UART_TX_PIN	= UART0_TX_PIN	//
)
const (
	// #===========#==========#==============#==================#=======#=======#
	// | Interface | Hardware |  Bus(Freq)   | SCK/SDI/SDO Pins | AltFn | Alias |
	// #===========#==========#==============#==================#=======#=======#
	// |   SPI1    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   |   ~   |
	// |   SPI2    |   SPI3   | APB1(42 MHz) |     D2/D3/D4     |   6   |   ~   |
	// |   SPI3    |   SPI1   | APB2(84 MHz) |    D17/D18/D19   |   5   |   ~   |
	// | --------- | -------- | ------------ | ---------------- | ----- | ----- |
	// |   SPI0    |   SPI2   | APB1(42 MHz) |    D23/D24/D25   |   5   | SPI1  |
	// #===========#==========#==============#==================#=======#=======#
	NUM_SPI_INTERFACES	= 3

	SPI1_SCK_PIN	= D23	//
	SPI1_SDI_PIN	= D24	// SPI1 = hardware: SPI2
	SPI1_SDO_PIN	= D25	//

	SPI2_SCK_PIN	= D2	//
	SPI2_SDI_PIN	= D3	// SPI2 = hardware: SPI3
	SPI2_SDO_PIN	= D4	//

	SPI3_SCK_PIN	= D17	//
	SPI3_SDI_PIN	= D18	// SPI3 = hardware: SPI1
	SPI3_SDO_PIN	= D19	//

	SPI0_SCK_PIN	= SPI1_SCK_PIN	//
	SPI0_SDI_PIN	= SPI1_SDI_PIN	// SPI0 = alias: SPI1
	SPI0_SDO_PIN	= SPI1_SDO_PIN	//

	SPI_SCK_PIN	= SPI0_SCK_PIN	//
	SPI_SDI_PIN	= SPI0_SDI_PIN	// default/primary SPI pins
	SPI_SDO_PIN	= SPI0_SDO_PIN	//
)
const (
	// #===========#==========#==============#==============#=======#=======#
	// | Interface | Hardware |  Bus(Freq)   | SDA/SCL Pins | AltFn | Alias |
	// #===========#==========#==============#==============#=======#=======#
	// |   I2C1    |   I2C1   | APB1(42 MHz) |   D14/D15    |   4   |   ~   |
	// |   I2C2    |   I2C2   | APB1(42 MHz) |    D0/D1     |   4   |   ~   |
	// |   I2C3    |   I2C1   | APB1(42 MHz) |    D9/D10    |   4   |   ~   |
	// | --------- | -------- | ------------ | ------------ | ----- | ----- |
	// |   I2C0    |   I2C1   | APB1(42 MHz) |   D14/D15    |   4   | I2C1  |
	// #===========#==========#==============#==============#=======#=======#
	NUM_I2C_INTERFACES	= 3

	I2C1_SDA_PIN	= D14	// I2C1 = hardware: I2C1
	I2C1_SCL_PIN	= D15	//

	I2C2_SDA_PIN	= D0	// I2C2 = hardware: I2C2
	I2C2_SCL_PIN	= D1	//

	I2C3_SDA_PIN	= D9	// I2C3 = hardware: I2C1
	I2C3_SCL_PIN	= D10	//   (interface duplicated on second pair of pins)

	I2C0_SDA_PIN	= I2C1_SDA_PIN	// I2C0 = alias: I2C1
	I2C0_SCL_PIN	= I2C1_SCL_PIN	//

	I2C_SDA_PIN	= I2C0_SDA_PIN	// default/primary I2C pins
	I2C_SCL_PIN	= I2C0_SCL_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.

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 (
	DutyCycle2	= 0
	DutyCycle16x9	= 1
)

I2C fast mode (Fm) duty cycle

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 PWM_MODE1 = 0x6
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

	PF0	= portF + 0
	PF1	= portF + 1
	PF2	= portF + 2
	PF3	= portF + 3
	PF4	= portF + 4
	PF5	= portF + 5
	PF6	= portF + 6
	PF7	= portF + 7
	PF8	= portF + 8
	PF9	= portF + 9
	PF10	= portF + 10
	PF11	= portF + 11
	PF12	= portF + 12
	PF13	= portF + 13
	PF14	= portF + 14
	PF15	= portF + 15

	PH0	= portH + 0
	PH1	= portH + 1
	PH2	= portH + 2
	PH3	= portH + 3
	PH4	= portH + 4
	PH5	= portH + 5
	PH6	= portH + 6
	PH7	= portH + 7
	PH8	= portH + 8
	PH9	= portH + 9
	PH10	= portH + 10
	PH11	= portH + 11
	PH12	= portH + 12
	PH13	= portH + 13
	PH14	= portH + 14
	PH15	= portH + 15

	PI0	= portI + 0
	PI1	= portI + 1
	PI2	= portI + 2
	PI3	= portI + 3
	PI4	= portI + 4
	PI5	= portI + 5
	PI6	= portI + 6
	PI7	= portI + 7
	PI8	= portI + 8
	PI9	= portI + 9
	PI10	= portI + 10
	PI11	= portI + 11
	PI12	= portI + 12
	PI13	= portI + 13
	PI14	= portI + 14
	PI15	= portI + 15
)
const (
	ARR_MAX	= 0x10000
	PSC_MAX	= 0x10000
)
const APB1_TIM_FREQ = 42000000 * 2

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 = 84000000 * 2
const (
	AF0_SYSTEM			= 0
	AF1_TIM1_2			= 1
	AF2_TIM3_4_5			= 2
	AF3_TIM8_9_10_11		= 3
	AF4_I2C1_2_3			= 4
	AF5_SPI1_SPI2			= 5
	AF6_SPI3			= 6
	AF7_USART1_2_3			= 7
	AF8_USART4_5_6			= 8
	AF9_CAN1_CAN2_TIM12_13_14	= 9
	AF10_OTG_FS_OTG_HS		= 10
	AF11_ETH			= 11
	AF12_FSMC_SDIO_OTG_HS_1		= 12
	AF13_DCMI			= 13
	AF14				= 14
	AF15_EVENTOUT			= 15
)

Alternative peripheral pin functions

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	= 0

	// ParityEven means to expect that the total number of 1 bits sent
	// should be an even number.
	ParityEven	UARTParity	= 1

	// ParityOdd means to expect that the total number of 1 bits sent
	// should be an odd number.
	ParityOdd	UARTParity	= 2
)

Variables

var (
	UART1	= &_UART1
	_UART1	= UART{
		Buffer:			NewRingBuffer(),
		Bus:			stm32.USART3,
		TxAltFuncSelector:	AF7_USART1_2_3,
		RxAltFuncSelector:	AF7_USART1_2_3,
	}
	UART2	= &_UART2
	_UART2	= UART{
		Buffer:			NewRingBuffer(),
		Bus:			stm32.USART6,
		TxAltFuncSelector:	AF8_USART4_5_6,
		RxAltFuncSelector:	AF8_USART4_5_6,
	}
	UART3	= &_UART3
	_UART3	= UART{
		Buffer:			NewRingBuffer(),
		Bus:			stm32.USART1,
		TxAltFuncSelector:	AF7_USART1_2_3,
		RxAltFuncSelector:	AF7_USART1_2_3,
	}
	DefaultUART	= UART1
)
var (
	SPI1	= SPI{
		Bus:			stm32.SPI2,
		AltFuncSelector:	AF5_SPI1_SPI2,
	}
	SPI2	= SPI{
		Bus:			stm32.SPI3,
		AltFuncSelector:	AF6_SPI3,
	}
	SPI3	= SPI{
		Bus:			stm32.SPI1,
		AltFuncSelector:	AF5_SPI1_SPI2,
	}
	SPI0	= SPI1
)
var (
	I2C1	= &I2C{
		Bus:			stm32.I2C1,
		AltFuncSelector:	AF4_I2C1_2_3,
	}
	I2C2	= &I2C{
		Bus:			stm32.I2C2,
		AltFuncSelector:	AF4_I2C1_2_3,
	}
	I2C3	= &I2C{
		Bus:			stm32.I2C1,
		AltFuncSelector:	AF4_I2C1_2_3,
	}
	I2C0	= I2C1
)
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 (
	TIM1	= TIM{
		EnableRegister:	&stm32.RCC.APB2ENR,
		EnableFlag:	stm32.RCC_APB2ENR_TIM1EN,
		Device:		stm32.TIM1,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA8, AF1_TIM1_2}, {PE9, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA9, AF1_TIM1_2}, {PE11, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA10, AF1_TIM1_2}, {PE13, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA11, AF1_TIM1_2}, {PE14, AF1_TIM1_2}}},
		},
		busFreq:	APB2_TIM_FREQ,
	}

	TIM2	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM2EN,
		Device:		stm32.TIM2,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA0, AF1_TIM1_2}, {PA5, AF1_TIM1_2}, {PA15, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA1, AF1_TIM1_2}, {PB3, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA2, AF1_TIM1_2}, {PB10, AF1_TIM1_2}}},
			TimerChannel{Pins: []PinFunction{{PA3, AF1_TIM1_2}, {PB11, AF1_TIM1_2}}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM3	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM3EN,
		Device:		stm32.TIM3,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA6, AF2_TIM3_4_5}, {PB4, AF2_TIM3_4_5}, {PC6, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PA7, AF2_TIM3_4_5}, {PB5, AF2_TIM3_4_5}, {PC7, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PB0, AF2_TIM3_4_5}, {PC8, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PB1, AF2_TIM3_4_5}, {PC9, AF2_TIM3_4_5}}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM4	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM4EN,
		Device:		stm32.TIM4,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PB6, AF2_TIM3_4_5}, {PD12, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PB7, AF2_TIM3_4_5}, {PD13, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PB8, AF2_TIM3_4_5}, {PD14, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PB9, AF2_TIM3_4_5}, {PD15, AF2_TIM3_4_5}}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM5	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM5EN,
		Device:		stm32.TIM5,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PH10, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PH11, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PH12, AF2_TIM3_4_5}}},
			TimerChannel{Pins: []PinFunction{{PI0, AF2_TIM3_4_5}}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM6	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_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.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM7EN,
		Device:		stm32.TIM7,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM8	= TIM{
		EnableRegister:	&stm32.RCC.APB2ENR,
		EnableFlag:	stm32.RCC_APB2ENR_TIM8EN,
		Device:		stm32.TIM8,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PC6, AF3_TIM8_9_10_11}, {PI5, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{{PC7, AF3_TIM8_9_10_11}, {PI6, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{{PC8, AF3_TIM8_9_10_11}, {PI7, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{{PC9, AF3_TIM8_9_10_11}, {PI2, AF3_TIM8_9_10_11}}},
		},
		busFreq:	APB2_TIM_FREQ,
	}

	TIM9	= TIM{
		EnableRegister:	&stm32.RCC.APB2ENR,
		EnableFlag:	stm32.RCC_APB2ENR_TIM9EN,
		Device:		stm32.TIM9,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA2, AF3_TIM8_9_10_11}, {PE5, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{{PA3, AF3_TIM8_9_10_11}, {PE6, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB2_TIM_FREQ,
	}

	TIM10	= TIM{
		EnableRegister:	&stm32.RCC.APB2ENR,
		EnableFlag:	stm32.RCC_APB2ENR_TIM10EN,
		Device:		stm32.TIM10,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PB8, AF3_TIM8_9_10_11}, {PF6, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB2_TIM_FREQ,
	}

	TIM11	= TIM{
		EnableRegister:	&stm32.RCC.APB2ENR,
		EnableFlag:	stm32.RCC_APB2ENR_TIM11EN,
		Device:		stm32.TIM11,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PB9, AF3_TIM8_9_10_11}, {PF7, AF3_TIM8_9_10_11}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB2_TIM_FREQ,
	}

	TIM12	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM12EN,
		Device:		stm32.TIM12,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PB14, AF9_CAN1_CAN2_TIM12_13_14}, {PH6, AF9_CAN1_CAN2_TIM12_13_14}}},
			TimerChannel{Pins: []PinFunction{{PB15, AF9_CAN1_CAN2_TIM12_13_14}, {PH9, AF9_CAN1_CAN2_TIM12_13_14}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM13	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM13EN,
		Device:		stm32.TIM13,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA6, AF9_CAN1_CAN2_TIM12_13_14}, {PF8, AF9_CAN1_CAN2_TIM12_13_14}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB1_TIM_FREQ,
	}

	TIM14	= TIM{
		EnableRegister:	&stm32.RCC.APB1ENR,
		EnableFlag:	stm32.RCC_APB1ENR_TIM14EN,
		Device:		stm32.TIM14,
		Channels: [4]TimerChannel{
			TimerChannel{Pins: []PinFunction{{PA7, AF9_CAN1_CAN2_TIM12_13_14}, {PF9, AF9_CAN1_CAN2_TIM12_13_14}}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
			TimerChannel{Pins: []PinFunction{}},
		},
		busFreq:	APB1_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 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)
}

ADCConfig holds ADC configuration parameters. If left unspecified, the zero value of each parameter will use the peripheral’s default settings.

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

Configure is intended to setup the STM32 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

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
	DutyCycle	uint8
}

I2CConfig is used to store config info for I2C.

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 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.

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 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
}

func (SPI) Configure

func (spi SPI) Configure(config SPIConfig)

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 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 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 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
}

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 int

UARTParity is the parity setting to be used for UART communication.