Documentation

Overview

Package spi allows users to read from and write to an SPI device.

Deprecated

This package is not maintained anymore. An actively supported cross-platform alternative is https://periph.io/.

Example

    Example illustrates a program that drives an APA-102 LED strip.

    Output:
    
    

    Index

    Examples

    Constants

    View Source
    const (
    	Mode0 = Mode(0)
    	Mode1 = Mode(1)
    	Mode2 = Mode(2)
    	Mode3 = Mode(3)
    )
    View Source
    const (
    	MSBFirst = Order(0)
    	LSBFirst = Order(1)
    )

    Variables

    This section is empty.

    Functions

    This section is empty.

    Types

    type Devfs

    type Devfs struct {
    	// Dev is the device to be opened.
    	// Device name is usually in the /dev/spidev<bus>.<chip> format.
    	// Required.
    	Dev string
    
    	// Mode is the SPI mode. SPI mode is a combination of polarity and phases.
    	// CPOL is the high order bit, CPHA is the low order. Pre-computed mode
    	// values are Mode0, Mode1, Mode2 and Mode3. The value of the mode argument
    	// can be overriden by the device's driver.
    	// Required.
    	Mode Mode
    
    	// MaxSpeed is the max clock speed (Hz) and can be overriden by the device's driver.
    	// Required.
    	MaxSpeed int64
    }

      Devfs is an SPI driver that works against the devfs. You need to have loaded the "spidev" Linux module to use this driver.

      func (*Devfs) Open

      func (d *Devfs) Open() (driver.Conn, error)

        Open opens the provided device with the specified options and returns a connection.

        type Device

        type Device struct {
        	// contains filtered or unexported fields
        }

        func Open

        func Open(o driver.Opener) (*Device, error)

        func (*Device) Close

        func (d *Device) Close() error

          Close closes the SPI device and releases the related resources.

          func (*Device) SetBitOrder

          func (d *Device) SetBitOrder(o Order) error

            SetBitOrder sets the bit justification used to transfer SPI words. Valid values are MSBFirst and LSBFirst.

            func (*Device) SetBitsPerWord

            func (d *Device) SetBitsPerWord(bits int) error

              SetBitsPerWord sets how many bits it takes to represent a word, e.g. 8 represents 8-bit words. The default is 8 bits per word.

              func (*Device) SetCSChange

              func (d *Device) SetCSChange(leaveEnabled bool) error

                SetCSChange sets whether to leave the chipselect enabled after a Tx.

                func (*Device) SetDelay

                func (d *Device) SetDelay(t time.Duration) error

                  SetDelay sets the amount of pause will be added after each frame write.

                  func (*Device) SetMaxSpeed

                  func (d *Device) SetMaxSpeed(speed int) error

                    SetMaxSpeed sets the maximum clock speed in Hz. The value can be overriden by SPI device's driver.

                    func (*Device) SetMode

                    func (d *Device) SetMode(mode Mode) error

                      SetMode sets the SPI mode. SPI mode is a combination of polarity and phases. CPOL is the high order bit, CPHA is the low order. Pre-computed mode values are Mode0, Mode1, Mode2 and Mode3. The value can be changed by SPI device's driver.

                      func (*Device) Tx

                      func (d *Device) Tx(w, r []byte) error

                        Tx performs a duplex transmission to write w to the SPI device and read len(r) bytes to r. User should not mutate the w and r until this call returns.

                        type Mode

                        type Mode int

                          Mode represents the SPI mode number where clock parity (CPOL) is the high order and clock edge (CPHA) is the low order bit.

                          type Order

                          type Order int

                            Order is the bit justification to be used while transfering words to the SPI device. MSB-first encoding is more popular than LSB-first.

                            GOOS=linux, GOARCH=amd64

                            Source Files

                            Directories

                            Path Synopsis
                            Package driver contains interfaces to be implemented by various SPI implementations.
                            Package driver contains interfaces to be implemented by various SPI implementations.