grandcentral-m4

Constants

const (
	//  = Pin     Alt. Function        SERCOM   PWM Timer   Interrupt
	//   ------  -------------------- -------- ----------- -----------
	D0	= PB25	// UART1 RX              0[1]                 EXTI9
	D1	= PB24	// UART1 TX              0[0]                 EXTI8
	D2	= PC18	//                                TCC0[2]     EXTI2
	D3	= PC19	//                                TCC0[3]     EXTI3
	D4	= PC20	//                                TCC0[4]     EXTI4
	D5	= PC21	//                                TCC0[5]     EXTI5
	D6	= PD20	//                                TCC1[0]     EXTI10
	D7	= PD21	//                                TCC1[1]     EXTI11
	D8	= PB18	//                                TCC1[0]     EXTI2
	D9	= PB02	//                                TC6[0]      EXTI3
	D10	= PB22	//                                TC7[0]      EXTI6
	D11	= PB23	//                                            EXTI7
	D12	= PB00	//                                TC7[0]      EXTI0
	D13	= PB01	// On-board LED                   TC7[1]      EXTI1
	D14	= PB16	// UART4 TX, I2S0 SCK    5[0]     TC6[0]      EXTI0
	D15	= PB17	// UART4 RX, I2S0 MCK    5[1]                 EXTI1
	D16	= PC22	// UART3 TX              1[0]                 EXTI6
	D17	= PC23	// UART3 RX              1[1]                 EXTI6
	D18	= PB12	// UART2 TX              4[0]     TCC3[0]     EXTI12
	D19	= PB13	// UART2 RX              4[1]     TCC3[1]     EXTI13
	D20	= PB20	// I2C0 SDA              3[0]                 EXTI4
	D21	= PB21	// I2C0 SCL              3[1]                 EXTI5
	D22	= PD12	//                                            EXTI7
	D23	= PA15	//                                TCC2[1]     EXTI15
	D24	= PC17	// I2C1 SCL              6[1]     TCC0[1]     EXTI1
	D25	= PC16	// I2C1 SDA              6[0]     TCC0[0]     EXTI0
	D26	= PA12	// PCC DEN1                       TC2[0]      EXTI12
	D27	= PA13	// PCC DEN2                       TC2[1]      EXTI13
	D28	= PA14	// PCC CLK                        TCC2[0]     EXTI14
	D29	= PB19	// PCC XCLK                                   EXTI3
	D30	= PA23	// PCC D7                         TC4[1]      EXTI7
	D31	= PA22	// PCC D6, I2S0 SDI               TC4[0]      EXTI6
	D32	= PA21	// PCC D5, I2S0 SDO                           EXTI5
	D33	= PA20	// PCC D4, I2S0 FS                            EXTI4
	D34	= PA19	// PCC D3                         TC3[1]      EXTI3
	D35	= PA18	// PCC D2                         TC3[0]      EXTI2
	D36	= PA17	// PCC D1                                     EXTI1
	D37	= PA16	// PCC D0                                     EXTI0
	D38	= PB15	// PCC D9                         TCC4[1]     EXTI15
	D39	= PB14	// PCC D8                         TCC4[0]     EXTI14
	D40	= PC13	// PCC D11                                    EXTI13
	D41	= PC12	// PCC D10                                    EXTI12
	D42	= PC15	// PCC D13                                    EXTI15
	D43	= PC14	// PCC D12                                    EXTI14
	D44	= PC11	//                                            EXTI11
	D45	= PC10	//                                            EXTI10
	D46	= PC06	//                                            EXTI6
	D47	= PC07	//                                            EXTI5
	D48	= PC04	//                                            EXTI4
	D49	= PC05	//                                            EXTI5
	D50	= PD11	// SPI0 SDI              7[3]                 EXTI11
	D51	= PD08	// SPI0 SDO              7[0]                 EXTI8
	D52	= PD09	// SPI0 SCK              7[1]                 EXTI9
	D53	= PD10	// SPI0 CS                                    EXTI10
	D54	= PB05	// ADC1 (A8)                                  EXTI5
	D55	= PB06	// ADC1 (A9)                                  EXTI6
	D56	= PB07	// ADC1 (A10)                                 EXTI7
	D57	= PB08	// ADC1 (A11)                                 EXTI8
	D58	= PB09	// ADC1 (A12)                                 EXTI9
	D59	= PA04	// ADC0 (A13)                     TC0[0]      EXTI4
	D60	= PA06	// ADC0 (A14)                     TC1[0]      EXTI6
	D61	= PA07	// ADC0 (A15)                     TC1[1]      EXTI7
	D62	= PB20	// I2C0 SDA              3[0]     TCC1[2]     EXTI4
	D63	= PB21	// I2C0 SCL              3[1]     TCC1[3]     EXTI5
	D64	= PD11	// SPI0 SDI              7[3]                 EXTI6
	D65	= PD08	// SPI0 SDO              7[0]                 EXTI3
	D66	= PD09	// SPI0 SCK              7[1]                 EXTI4
	D67	= PA02	// ADC0 (A0), DAC0                            EXTI2
	D68	= PA05	// ADC0 (A1), DAC1                            EXTI5
	D69	= PB03	// ADC0 (A2)                      TC6[1]      EXTI3
	D70	= PC00	// ADC1 (A3)                                  EXTI0
	D71	= PC01	// ADC1 (A4)                                  EXTI1
	D72	= PC02	// ADC1 (A5)                                  EXTI2
	D73	= PC03	// ADC1 (A6)                                  EXTI3
	D74	= PB04	// ADC1 (A7)                                  EXTI4
	D75	= PC31	// UART RX LED
	D76	= PC30	// UART TX LED
	D77	= PA27	// USB HOST EN
	D78	= PA24	// USB DM                                     EXTI8
	D79	= PA25	// USB DP                                     EXTI9
	D80	= PB29	// SD/SPI1 SDI           2[3]
	D81	= PB27	// SD/SPI1 SCK           2[1]
	D82	= PB26	// SD/SPI1 SDO           2[0]
	D83	= PB28	// SD/SPI1 CS
	D84	= PA03	// AREF                                       EXTI3
	D85	= PA02	// DAC0                                       EXTI2
	D86	= PA05	// DAC1                                       EXTI5
	D87	= PB01	// On-board LED (D13)             TC7[1]      EXTI1
	D88	= PC24	// On-board NeoPixel
	D89	= PB10	// QSPI SCK                                   EXTI10
	D90	= PB11	// QSPI CS                                    EXTI11
	D91	= PA08	// QSPI ID0                                   EXTI(NMI)
	D92	= PA09	// QSPI ID1                                   EXTI9
	D93	= PA10	// QSPI ID2                                   EXTI10
	D94	= PA11	// QSPI ID3                                   EXTI11
	D95	= PB31	// SD Detect                                  EXTI15
	D96	= PB30	// SWO                                        EXTI14
)

Digital pins

const (
	A0	= D67	// (PA02) ADC0 ch. 0,
	A1	= D68	// (PA05) ADC0 ch. 5,
	A2	= D69	// (PB03) ADC0 ch. 15
	A3	= D70	// (PC00) ADC1 ch. 10
	A4	= D71	// (PC01) ADC1 ch. 11
	A5	= D72	// (PC02) ADC1 ch. 4
	A6	= D73	// (PC03) ADC1 ch. 5
	A7	= D74	// (PB04) ADC1 ch. 6
	A8	= D54	// (PB05) ADC1 ch. 7
	A9	= D55	// (PB06) ADC1 ch. 8
	A10	= D56	// (PB07) ADC1 ch. 9
	A11	= D57	// (PB08) ADC1 ch. 0
	A12	= D58	// (PB09) ADC1 ch. 1
	A13	= D59	// (PA04) ADC0 ch. 4
	A14	= D60	// (PA06) ADC0 ch. 6
	A15	= D61	// (PA07) ADC0 ch. 7

	AREF	= D84	// (PA03)
)

Analog pins

const (
	LED_PIN		= D13	// (PB01), also on D87
	UART_RX_LED_PIN	= D75	// (PC31)
	UART_TX_LED_PIN	= D76	// (PC30)
	NEOPIXEL_PIN	= D88	// (PC24)

	// aliases used by examples and drivers
	LED		= LED_PIN
	LED_RX		= UART_RX_LED_PIN
	LED_TX		= UART_TX_LED_PIN
	NEOPIXEL	= NEOPIXEL_PIN
	WS2812		= NEOPIXEL_PIN
)

LED pins

const (
	UART1_RX_PIN	= D0	// (PB25)
	UART1_TX_PIN	= D1	// (PB24)

	UART2_RX_PIN	= D19	// (PB13)
	UART2_TX_PIN	= D18	// (PB12)

	UART3_RX_PIN	= D17	// (PC23)
	UART3_TX_PIN	= D16	// (PC22)

	UART4_RX_PIN	= D15	// (PB17)
	UART4_TX_PIN	= D14	// (PB16)

	UART_RX_PIN	= UART1_RX_PIN	// default pins
	UART_TX_PIN	= UART1_TX_PIN	//
)

UART pins

const (
	SPI0_SCK_PIN	= D66	// (PD09), also on D52
	SPI0_SDO_PIN	= D65	// (PD08), also on D51
	SPI0_SDI_PIN	= D64	// (PD11), also on D50
	SPI0_CS_PIN	= D53	// (PD10)

	SPI1_SCK_PIN	= D81	// (PB27)
	SPI1_SDO_PIN	= D82	// (PB26)
	SPI1_SDI_PIN	= D80	// (PB29)

	SPI_SCK_PIN	= SPI0_SCK_PIN	// default pins
	SPI_SDO_PIN	= SPI0_SDO_PIN	//
	SPI_SDI_PIN	= SPI0_SDI_PIN	//
	SPI_CS_PIN	= SPI0_CS_PIN	//
)

SPI pins

const (
	I2C0_SDA_PIN	= D62	// (PB20), also on D20
	I2C0_SCL_PIN	= D63	// (PB21), also on D21

	I2C1_SDA_PIN	= D25	// (PC16)
	I2C1_SCL_PIN	= D24	// (PC17)

	I2C_SDA_PIN	= I2C0_SDA_PIN	// default pins
	I2C_SCL_PIN	= I2C0_SCL_PIN	//

	SDA_PIN	= I2C_SDA_PIN	// unconventional pin names
	SCL_PIN	= I2C_SCL_PIN	//  (required by machine_atsamd51.go)
)

I2C pins

const (
	I2S0_SCK_PIN	= D14	// (PB16)
	I2S0_MCK_PIN	= D15	// (PB17)
	I2S0_FS_PIN	= D33	// (PA20)
	I2S0_SDO_PIN	= D32	// (PA21)
	I2S0_SDI_PIN	= D31	// (PA22)

	I2S_SCK_PIN	= I2S0_SCK_PIN	// default pins
	I2S_WS_PIN	= I2S0_FS_PIN	//
	I2S_SD_PIN	= I2S0_SDO_PIN	//
)

I2S pins

const (
	SD0_SCK_PIN	= D81	// (PB27)
	SD0_SDO_PIN	= D82	// (PB26)
	SD0_SDI_PIN	= D80	// (PB29)
	SD0_CS_PIN	= D83	// (PB28)
	SD0_DET_PIN	= D95	// (PB31)

	SDCARD_SCK_PIN	= SD0_SCK_PIN	// default pins
	SDCARD_SDO_PIN	= SD0_SDO_PIN	//
	SDCARD_SDI_PIN	= SD0_SDI_PIN	//
	SDCARD_CS_PIN	= SD0_CS_PIN	//
	SDCARD_DET_PIN	= SD0_DET_PIN	//
)

SD card pins

const (
	USBCDC_HOSTEN_PIN	= D77	// (PA27) host enable
	USBCDC_DM_PIN		= D78	// (PA24) D-
	USBCDC_DP_PIN		= D79	// (PA25) D+
)

USB CDC 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.

Deprecated: use 100 * machine.KHz or 400 * machine.KHz instead.

const (
	I2SModeSource	I2SMode	= iota
	I2SModeReceiver
	I2SModePDM
)
const (
	I2StandardPhilips	I2SStandard	= iota
	I2SStandardMSB
	I2SStandardLSB
)
const (
	I2SClockSourceInternal	I2SClockSource	= iota
	I2SClockSourceExternal
)
const (
	I2SDataFormatDefault	I2SDataFormat	= 0
	I2SDataFormat8bit			= 8
	I2SDataFormat16bit			= 16
	I2SDataFormat24bit			= 24
	I2SDataFormat32bit			= 32
)
const Device = deviceName

Device is the running program’s chip name, such as “ATSAMD51J19A” or “nrf52840”. It is not the same as the CPU name.

The constant is some hardcoded default value if the program does not target a particular chip but instead runs in WebAssembly for example.

const (
	KHz	= 1000
	MHz	= 1000_000
	GHz	= 1000_000_000
)

Generic constants.

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 (
	PinAnalog		PinMode	= 1
	PinSERCOM		PinMode	= 2
	PinSERCOMAlt		PinMode	= 3
	PinTimer		PinMode	= 4
	PinTimerAlt		PinMode	= 5
	PinTCCPDEC		PinMode	= 6
	PinCom			PinMode	= 7
	PinSDHC			PinMode	= 8
	PinI2S			PinMode	= 9
	PinPCC			PinMode	= 10
	PinGMAC			PinMode	= 11
	PinACCLK		PinMode	= 12
	PinCCL			PinMode	= 13
	PinDigital		PinMode	= 14
	PinInput		PinMode	= 15
	PinInputPullup		PinMode	= 16
	PinOutput		PinMode	= 17
	PinTCCE			PinMode	= PinTimer
	PinTCCF			PinMode	= PinTimerAlt
	PinTCCG			PinMode	= PinTCCPDEC
	PinInputPulldown	PinMode	= 18
	PinCAN			PinMode	= 19
	PinCAN0			PinMode	= PinSDHC
	PinCAN1			PinMode	= PinCom
)
const (
	PinRising	PinChange	= sam.EIC_CONFIG_SENSE0_RISE
	PinFalling	PinChange	= sam.EIC_CONFIG_SENSE0_FALL
	PinToggle	PinChange	= sam.EIC_CONFIG_SENSE0_BOTH
)

Pin change interrupt constants for SetInterrupt.

const (
	PA00	Pin	= 0
	PA01	Pin	= 1
	PA02	Pin	= 2
	PA03	Pin	= 3
	PA04	Pin	= 4
	PA05	Pin	= 5
	PA06	Pin	= 6
	PA07	Pin	= 7
	PA08	Pin	= 8	// peripherals: TCC0 channel 0, TCC1 channel 4
	PA09	Pin	= 9	// peripherals: TCC0 channel 1, TCC1 channel 5
	PA10	Pin	= 10	// peripherals: TCC0 channel 2, TCC1 channel 6
	PA11	Pin	= 11	// peripherals: TCC0 channel 3, TCC1 channel 7
	PA12	Pin	= 12	// peripherals: TCC0 channel 6, TCC1 channel 2
	PA13	Pin	= 13	// peripherals: TCC0 channel 7, TCC1 channel 3
	PA14	Pin	= 14	// peripherals: TCC2 channel 0, TCC1 channel 2
	PA15	Pin	= 15	// peripherals: TCC2 channel 1, TCC1 channel 3
	PA16	Pin	= 16	// peripherals: TCC1 channel 0, TCC0 channel 4
	PA17	Pin	= 17	// peripherals: TCC1 channel 1, TCC0 channel 5
	PA18	Pin	= 18	// peripherals: TCC1 channel 2, TCC0 channel 6
	PA19	Pin	= 19	// peripherals: TCC1 channel 3, TCC0 channel 7
	PA20	Pin	= 20	// peripherals: TCC1 channel 4, TCC0 channel 0
	PA21	Pin	= 21	// peripherals: TCC1 channel 5, TCC0 channel 1
	PA22	Pin	= 22	// peripherals: TCC1 channel 6, TCC0 channel 2
	PA23	Pin	= 23	// peripherals: TCC1 channel 7, TCC0 channel 3
	PA24	Pin	= 24	// peripherals: TCC2 channel 2
	PA25	Pin	= 25	// peripherals: TCC2 channel 3
	PA26	Pin	= 26
	PA27	Pin	= 27
	PA28	Pin	= 28
	PA29	Pin	= 29
	PA30	Pin	= 30	// peripherals: TCC2 channel 0
	PA31	Pin	= 31	// peripherals: TCC2 channel 1
	PB00	Pin	= 32
	PB01	Pin	= 33
	PB02	Pin	= 34	// peripherals: TCC2 channel 2
	PB03	Pin	= 35	// peripherals: TCC2 channel 3
	PB04	Pin	= 36
	PB05	Pin	= 37
	PB06	Pin	= 38
	PB07	Pin	= 39
	PB08	Pin	= 40
	PB09	Pin	= 41
	PB10	Pin	= 42	// peripherals: TCC0 channel 4, TCC1 channel 0
	PB11	Pin	= 43	// peripherals: TCC0 channel 5, TCC1 channel 1
	PB12	Pin	= 44	// peripherals: TCC3 channel 0, TCC0 channel 0
	PB13	Pin	= 45	// peripherals: TCC3 channel 1, TCC0 channel 1
	PB14	Pin	= 46	// peripherals: TCC4 channel 0, TCC0 channel 2
	PB15	Pin	= 47	// peripherals: TCC4 channel 1, TCC0 channel 3
	PB16	Pin	= 48	// peripherals: TCC3 channel 0, TCC0 channel 4
	PB17	Pin	= 49	// peripherals: TCC3 channel 1, TCC0 channel 5
	PB18	Pin	= 50	// peripherals: TCC1 channel 0
	PB19	Pin	= 51	// peripherals: TCC1 channel 1
	PB20	Pin	= 52	// peripherals: TCC1 channel 2
	PB21	Pin	= 53	// peripherals: TCC1 channel 3
	PB22	Pin	= 54
	PB23	Pin	= 55
	PB24	Pin	= 56
	PB25	Pin	= 57
	PB26	Pin	= 58	// peripherals: TCC1 channel 2
	PB27	Pin	= 59	// peripherals: TCC1 channel 3
	PB28	Pin	= 60	// peripherals: TCC1 channel 4
	PB29	Pin	= 61	// peripherals: TCC1 channel 5
	PB30	Pin	= 62	// peripherals: TCC4 channel 0, TCC0 channel 6
	PB31	Pin	= 63	// peripherals: TCC4 channel 1, TCC0 channel 7
	PC00	Pin	= 64
	PC01	Pin	= 65
	PC02	Pin	= 66
	PC03	Pin	= 67
	PC04	Pin	= 68	// peripherals: TCC0 channel 0
	PC05	Pin	= 69	// peripherals: TCC0 channel 1
	PC06	Pin	= 70
	PC07	Pin	= 71
	PC08	Pin	= 72
	PC09	Pin	= 73
	PC10	Pin	= 74	// peripherals: TCC0 channel 0, TCC1 channel 4
	PC11	Pin	= 75	// peripherals: TCC0 channel 1, TCC1 channel 5
	PC12	Pin	= 76	// peripherals: TCC0 channel 2, TCC1 channel 6
	PC13	Pin	= 77	// peripherals: TCC0 channel 3, TCC1 channel 7
	PC14	Pin	= 78	// peripherals: TCC0 channel 4, TCC1 channel 0
	PC15	Pin	= 79	// peripherals: TCC0 channel 5, TCC1 channel 1
	PC16	Pin	= 80	// peripherals: TCC0 channel 0
	PC17	Pin	= 81	// peripherals: TCC0 channel 1
	PC18	Pin	= 82	// peripherals: TCC0 channel 2
	PC19	Pin	= 83	// peripherals: TCC0 channel 3
	PC20	Pin	= 84	// peripherals: TCC0 channel 4
	PC21	Pin	= 85	// peripherals: TCC0 channel 5
	PC22	Pin	= 86	// peripherals: TCC0 channel 6
	PC23	Pin	= 87	// peripherals: TCC0 channel 7
	PC24	Pin	= 88
	PC25	Pin	= 89
	PC26	Pin	= 90
	PC27	Pin	= 91
	PC28	Pin	= 92
	PC29	Pin	= 93
	PC30	Pin	= 94
	PC31	Pin	= 95
	PD00	Pin	= 96
	PD01	Pin	= 97
	PD02	Pin	= 98
	PD03	Pin	= 99
	PD04	Pin	= 100
	PD05	Pin	= 101
	PD06	Pin	= 102
	PD07	Pin	= 103
	PD08	Pin	= 104	// peripherals: TCC0 channel 1
	PD09	Pin	= 105	// peripherals: TCC0 channel 2
	PD10	Pin	= 106	// peripherals: TCC0 channel 3
	PD11	Pin	= 107	// peripherals: TCC0 channel 4
	PD12	Pin	= 108	// peripherals: TCC0 channel 5
	PD13	Pin	= 109	// peripherals: TCC0 channel 6
	PD14	Pin	= 110
	PD15	Pin	= 111
	PD16	Pin	= 112
	PD17	Pin	= 113
	PD18	Pin	= 114
	PD19	Pin	= 115
	PD20	Pin	= 116	// peripherals: TCC1 channel 0
	PD21	Pin	= 117	// peripherals: TCC1 channel 1
	PD22	Pin	= 118
	PD23	Pin	= 119
	PD24	Pin	= 120
	PD25	Pin	= 121
	PD26	Pin	= 122
	PD27	Pin	= 123
	PD28	Pin	= 124
	PD29	Pin	= 125
	PD30	Pin	= 126
	PD31	Pin	= 127
)

Hardware pins

const (
	// SERCOM_FREQ_REF is always reference frequency on SAMD51 regardless of CPU speed.
	SERCOM_FREQ_REF		= 48000000
	SERCOM_FREQ_REF_GCLK0	= 120000000

	// Default rise time in nanoseconds, based on 4.7K ohm pull up resistors
	riseTimeNanoseconds	= 125

	// wire bus states
	wireUnknownState	= 0
	wireIdleState		= 1
	wireOwnerState		= 2
	wireBusyState		= 3

	// wire commands
	wireCmdNoAction		= 0
	wireCmdRepeatStart	= 1
	wireCmdRead		= 2
	wireCmdStop		= 3
)
const (
	QSPI_SCK	= PB10
	QSPI_CS		= PB11
	QSPI_DATA0	= PA08
	QSPI_DATA1	= PA09
	QSPI_DATA2	= PA10
	QSPI_DATA3	= PA11
)

The QSPI peripheral on ATSAMD51 is only available on the following pins

const HSRAM_SIZE = 0x00040000
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	= iota

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

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

Variables

var (
	UART1	= &sercomUSART0
	UART2	= &sercomUSART4
	UART3	= &sercomUSART1
	UART4	= &sercomUSART5

	DefaultUART	= UART1
)

UART on the Grand Central M4

var (
	SPI0	= sercomSPIM7
	SPI1	= sercomSPIM2	// SD card
)

SPI on the Grand Central M4

var (
	I2C0	= sercomI2CM3
	I2C1	= sercomI2CM6
)

I2C on the Grand Central M4

var (
	ErrTimeoutRNG		= errors.New("machine: RNG Timeout")
	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 (
	DAC0	= DAC{Channel: 0}
	DAC1	= DAC{Channel: 1}
)
var (
	TCC0	= (*TCC)(sam.TCC0)
	TCC1	= (*TCC)(sam.TCC1)
	TCC2	= (*TCC)(sam.TCC2)
	TCC3	= (*TCC)(sam.TCC3)
	TCC4	= (*TCC)(sam.TCC4)
)

This chip has five TCC peripherals, which have PWM as one feature.

var (
	ErrPWMPeriodTooLong = errors.New("pwm: period too long")
)
var Serial Serialer

Serial is implemented via USB (USB-CDC).

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")
)
var (
	USBDev	= &USBDevice{}
	USBCDC	Serialer
)
var (
	ErrUSBReadTimeout	= errors.New("USB read timeout")
	ErrUSBBytesRead		= errors.New("USB invalid number of bytes read")
)

func CPUFrequency

func CPUFrequency() uint32

func EnableCDC

func EnableCDC(txHandler func(), rxHandler func([]byte), setupHandler func(usb.Setup) bool)

func EnableHID

func EnableHID(txHandler func(), rxHandler func([]byte), setupHandler func(usb.Setup) bool)

EnableHID enables HID. This function must be executed from the init().

func EnableMIDI

func EnableMIDI(txHandler func(), rxHandler func([]byte), setupHandler func(usb.Setup) bool)

EnableMIDI enables MIDI. This function must be executed from the init().

func EnterBootloader

func EnterBootloader()

EnterBootloader should perform a system reset in preparation to switch to the bootloader to flash new firmware.

func GetRNG

func GetRNG() (uint32, error)

GetRNG returns 32 bits of cryptographically secure random data

func InitADC

func InitADC()

InitADC initializes the ADC.

func InitSerial

func InitSerial()

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

func ReceiveUSBControlPacket

func ReceiveUSBControlPacket() ([cdcLineInfoSize]byte, error)

func SendUSBInPacket

func SendUSBInPacket(ep uint32, data []byte) bool

SendUSBInPacket sends a packet for USB (interrupt in / bulk in).

func SendZlp

func SendZlp()

type ADC

type ADC struct {
	Pin Pin
}

func (ADC) Configure

func (a ADC) Configure(config ADCConfig)

Configure configures a ADCPin to be able to be used to read data.

func (ADC) Get

func (a ADC) Get() uint16

Get returns the current value of a ADC pin, in the range 0..0xffff.

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 DAC

type DAC struct {
	Channel uint8
}

DAC on the SAMD51.

func (DAC) Configure

func (dac DAC) Configure(config DACConfig)

Configure the DAC. output pin must already be configured.

func (DAC) Set

func (dac DAC) Set(value uint16) error

Set writes a single 16-bit value to the DAC. Since the ATSAMD51 only has a 12-bit DAC, the passed-in value will be scaled down.

type DACConfig

type DACConfig struct {
}

DACConfig placeholder for future expansion.

type I2C

type I2C struct {
	Bus	*sam.SERCOM_I2CM_Type
	SERCOM	uint8
}

I2C on the SAMD51.

func (*I2C) Configure

func (i2c *I2C) Configure(config I2CConfig) error

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) SetBaudRate

func (i2c *I2C) SetBaudRate(br uint32)

SetBaudRate sets the communication speed for the I2C.

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(r) 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 I2SClockSource

type I2SClockSource uint8

type I2SConfig

type I2SConfig struct {
	SCK		Pin
	WS		Pin
	SD		Pin
	Mode		I2SMode
	Standard	I2SStandard
	ClockSource	I2SClockSource
	DataFormat	I2SDataFormat
	AudioFrequency	uint32
	MainClockOutput	bool
	Stereo		bool
}

All fields are optional and may not be required or used on a particular platform.

type I2SDataFormat

type I2SDataFormat uint8

type I2SMode

type I2SMode uint8

type I2SStandard

type I2SStandard uint8

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) Get

func (p Pin) Get() bool

Get returns the current value of a GPIO pin when configured as an input or as an output.

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) PortMaskClear

func (p Pin) PortMaskClear() (*uint32, uint32)

Return the register and mask to disable a given port. This can be used to implement bit-banged drivers.

func (Pin) PortMaskSet

func (p Pin) PortMaskSet() (*uint32, uint32)

Return the register and mask to enable a given GPIO pin. This can be used to implement bit-banged drivers.

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) 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).

func (Pin) Toggle

func (p Pin) Toggle()

Toggle switches an output pin from low to high or from high to low. Warning: only use this on an output pin!

type PinChange

type PinChange uint8

type PinConfig

type PinConfig struct {
	Mode PinMode
}

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	*sam.SERCOM_SPIM_Type
	SERCOM	uint8
}

SPI

func (SPI) Configure

func (spi SPI) Configure(config SPIConfig) error

Configure is intended to setup the SPI 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 Serialer

type Serialer interface {
	WriteByte(c byte) error
	Write(data []byte) (n int, err error)
	Configure(config UARTConfig) error
	Buffered() int
	ReadByte() (byte, error)
	DTR() bool
	RTS() bool
}

type TCC

type TCC sam.TCC_Type

TCC is one timer peripheral, which consists of a counter and multiple output channels (that can be connected to actual pins). You can set the frequency using SetPeriod, but only for all the channels in this timer peripheral at once.

func (*TCC) Channel

func (tcc *TCC) Channel(pin Pin) (uint8, error)

Channel returns a PWM channel for the given pin. Note that one channel may be shared between multiple pins, and so will have the same duty cycle. If this is not desirable, look for a different TCC or consider using a different pin.

func (*TCC) Configure

func (tcc *TCC) Configure(config PWMConfig) error

Configure enables and configures this TCC.

func (*TCC) Counter

func (tcc *TCC) Counter() uint32

Counter returns the current counter value of the timer in this TCC peripheral. It may be useful for debugging.

func (*TCC) Set

func (tcc *TCC) Set(channel uint8, value uint32)

Set updates the channel value. This is used to control the channel duty cycle, in other words the fraction of time the channel output is high (or low when inverted). For example, to set it to a 25% duty cycle, use:

tcc.Set(channel, tcc.Top() / 4)

tcc.Set(channel, 0) will set the output to low and tcc.Set(channel, tcc.Top()) will set the output to high, assuming the output isn’t inverted.

func (*TCC) SetInverting

func (tcc *TCC) 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 (*TCC) SetPeriod

func (tcc *TCC) SetPeriod(period uint64) error

SetPeriod updates the period of this TCC 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 TCC 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 (*TCC) Top

func (tcc *TCC) 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 tcc.Set (see tcc.Set for more information).

type UART

type UART struct {
	Buffer		*RingBuffer
	Bus		*sam.SERCOM_USART_INT_Type
	SERCOM		uint8
	Interrupt	interrupt.Interrupt	// RXC interrupt
}

UART on the SAMD51.

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) error

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
}

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 uint8

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

type USBDevice

type USBDevice struct {
	initcomplete bool
}

func (*USBDevice) Configure

func (dev *USBDevice) Configure(config UARTConfig)

Configure the USB peripheral. The config is here for compatibility with the UART interface.