arduino-mega2560

Constants

const (
	AREF	Pin	= NoPin
	LED	Pin	= PB7

	A0	Pin	= PF0
	A1	Pin	= PF1
	A2	Pin	= PF2
	A3	Pin	= PF3
	A4	Pin	= PF4
	A5	Pin	= PF5
	A6	Pin	= PF6
	A7	Pin	= PF7
	A8	Pin	= PK0
	A9	Pin	= PK1
	A10	Pin	= PK2
	A11	Pin	= PK3
	A12	Pin	= PK4
	A13	Pin	= PK5
	A14	Pin	= PK6
	A15	Pin	= PK7

	// Analog Input
	ADC0	Pin	= PF0
	ADC1	Pin	= PF1
	ADC2	Pin	= PF2
	ADC3	Pin	= PF3
	ADC4	Pin	= PF4
	ADC5	Pin	= PF5
	ADC6	Pin	= PF6
	ADC7	Pin	= PF7
	ADC8	Pin	= PK0
	ADC9	Pin	= PK1
	ADC10	Pin	= PK2
	ADC11	Pin	= PK3
	ADC12	Pin	= PK4
	ADC13	Pin	= PK5
	ADC14	Pin	= PK6
	ADC15	Pin	= PK7

	// Digital pins
	D0	Pin	= PE0
	D1	Pin	= PE1
	D2	Pin	= PE6
	D3	Pin	= PE5
	D4	Pin	= PG5
	D5	Pin	= PE3
	D6	Pin	= PH3
	D7	Pin	= PH4
	D8	Pin	= PH5
	D9	Pin	= PH6
	D10	Pin	= PB4
	D11	Pin	= PB5
	D12	Pin	= PB6
	D13	Pin	= PB7
	D14	Pin	= PJ1
	D15	Pin	= PJ0
	D16	Pin	= PH1
	D17	Pin	= PH0
	D18	Pin	= PD3
	D19	Pin	= PD2
	D20	Pin	= PD1
	D21	Pin	= PD0
	D22	Pin	= PA0
	D23	Pin	= PA1
	D24	Pin	= PA2
	D25	Pin	= PA3
	D26	Pin	= PA4
	D27	Pin	= PA5
	D28	Pin	= PA6
	D29	Pin	= PA7
	D30	Pin	= PC7
	D31	Pin	= PC6
	D32	Pin	= PC5
	D33	Pin	= PC4
	D34	Pin	= PC3
	D35	Pin	= PC2
	D36	Pin	= PC1
	D37	Pin	= PC0
	D38	Pin	= PD7
	D39	Pin	= PG2
	D40	Pin	= PG1
	D41	Pin	= PG0
	D42	Pin	= PL7
	D43	Pin	= PL6
	D44	Pin	= PL5
	D45	Pin	= PL4
	D46	Pin	= PL3
	D47	Pin	= PL2
	D48	Pin	= PL1
	D49	Pin	= PL0
	D50	Pin	= PB3
	D51	Pin	= PB2
	D52	Pin	= PB1
	D53	Pin	= PB0
)
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 (
	PA0	= portA + 0
	PA1	= portA + 1
	PA2	= portA + 2
	PA3	= portA + 3
	PA4	= portA + 4
	PA5	= portA + 5
	PA6	= portA + 6
	PA7	= portA + 7
	PB0	= portB + 0
	PB1	= portB + 1
	PB2	= portB + 2
	PB3	= portB + 3
	PB4	= portB + 4
	PB5	= portB + 5
	PB6	= portB + 6
	PB7	= portB + 7
	PC0	= portC + 0
	PC1	= portC + 1
	PC2	= portC + 2
	PC3	= portC + 3
	PC4	= portC + 4
	PC5	= portC + 5
	PC6	= portC + 6
	PC7	= portC + 7
	PD0	= portD + 0
	PD1	= portD + 1
	PD2	= portD + 2
	PD3	= portD + 3
	PD7	= portD + 7
	PE0	= portE + 0
	PE1	= portE + 1
	PE3	= portE + 2
	PE5	= portE + 5
	PE6	= portE + 6
	PF0	= portF + 0
	PF1	= portF + 1
	PF2	= portF + 2
	PF3	= portF + 3
	PF4	= portF + 4
	PF5	= portF + 5
	PF6	= portF + 6
	PF7	= portF + 7
	PG0	= portG + 0
	PG1	= portG + 1
	PG2	= portG + 2
	PG5	= portG + 5
	PH0	= portH + 0
	PH1	= portH + 1
	PH3	= portH + 3
	PH4	= portH + 4
	PH5	= portH + 5
	PH6	= portH + 6
	PJ0	= portJ + 0
	PJ1	= portJ + 1
	PK0	= portK + 0
	PK1	= portK + 1
	PK2	= portK + 2
	PK3	= portK + 3
	PK4	= portH + 4
	PK5	= portH + 5
	PK6	= portH + 6
	PK7	= portH + 7
	PL0	= portL + 0
	PL1	= portL + 1
	PL2	= portL + 2
	PL3	= portL + 3
	PL4	= portL + 4
	PL5	= portL + 5
	PL6	= portL + 6
	PL7	= portE + 7
)
const (
	PinInput	PinMode	= iota
	PinOutput
)

Variables

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 I2C0 = I2C{}

I2C0 is the only I2C interface on most AVRs.

var (
	// UART0 is the hardware serial port on the AVR.
	UART0 = UART{Buffer: NewRingBuffer()}
)

UART

func CPUFrequency

func CPUFrequency() uint32

Return the current CPU frequency in hertz.

func InitADC

func InitADC()

InitADC initializes the registers needed for ADC.

func InitPWM

func InitPWM()

InitPWM initializes the registers needed for PWM.

func NewRingBuffer

func NewRingBuffer() *RingBuffer

NewRingBuffer returns a new ring buffer.

type ADC

type ADC struct {
	Pin Pin
}

func (ADC) Configure

func (a ADC) Configure()

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. The AVR has an ADC of 10 bits precision so the lower 6 bits will be zero.

type I2C

type I2C struct {
}

I2C on AVR.

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) 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
}

I2CConfig is used to store config info for I2C.

type PWM

type PWM struct {
	Pin Pin
}

func (PWM) Configure

func (pwm PWM) Configure()

Configure configures a PWM pin for output.

func (PWM) Set

func (pwm PWM) Set(value uint16)

Set turns on the duty cycle for a PWM pin using the provided value. On the AVR this is normally a 8-bit value ranging from 0 to 255.

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 sets the pin to input or output.

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) PortMaskClear

func (p Pin) PortMaskClear() (*volatile.Register8, uint8)

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

Warning: there are no separate pin set/clear registers on the AVR. The returned mask is only valid as long as no other pin in the same port has been changed.

func (Pin) PortMaskSet

func (p Pin) PortMaskSet() (*volatile.Register8, uint8)

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

Warning: there are no separate pin set/clear registers on the AVR. The returned mask is only valid as long as no other pin in the same port has been changed.

func (Pin) Set

func (p Pin) Set(value bool)

Set changes the value of the GPIO pin. The pin must be configured as output.

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) 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 UART

type UART struct {
	Buffer *RingBuffer
}

UART on the AVR.

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 on the AVR. Defaults to 9600 baud on Arduino.

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) 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
}