max72xx

Documentation

Overview

Driver works for max7219 and 7221 Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX7219-MAX7221.pdf

Index

• Constants
• type Device
  • func NewDevice(bus machine.SPI, cs machine.Pin) *Device
  • func (driver *Device) Configure()
  • func (driver *Device) SetDecodeMode(digitNumber uint8)
  • func (driver *Device) SetScanLimit(digitNumber uint8)
  • func (driver *Device) StartDisplayTest()
  • func (driver *Device) StartShutdownMode()
  • func (driver *Device) StopDisplayTest()
  • func (driver *Device) StopShutdownMode()
  • func (driver *Device) WriteCommand(register, data byte)

Constants

const (
	REG_NOOP         byte = 0x00
	REG_DIGIT0       byte = 0x01
	REG_DIGIT1       byte = 0x02
	REG_DIGIT2       byte = 0x03
	REG_DIGIT3       byte = 0x04
	REG_DIGIT4       byte = 0x05
	REG_DIGIT5       byte = 0x06
	REG_DIGIT6       byte = 0x07
	REG_DIGIT7       byte = 0x08
	REG_DECODE_MODE  byte = 0x09 // turn of for led matrix, turn on for digits
	REG_INTENSITY    byte = 0x0A
	REG_SCANLIMIT    byte = 0x0B
	REG_SHUTDOWN     byte = 0x0C // turn on for no shutdown mode
	REG_DISPLAY_TEST byte = 0x0F // turn off for no display test
)

Types

type Device

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

func NewDevice

func NewDevice(bus machine.SPI, cs machine.Pin) *Device

NewDriver creates a new max7219 connection. The SPI wire must already be configured The SPI frequency must not be higher than 10MHz. parameter cs: the datasheet also refers to this pin as "load" pin.

func (*Device) Configure

func (driver *Device) Configure()

Configure setups the pins.

func (*Device) SetDecodeMode

func (driver *Device) SetDecodeMode(digitNumber uint8)

SetDecodeMode sets the decode mode for 7 segment displays. digitNumber = 1 -> 1 digit gets decoded digitNumber = 2 or 3, or 4 -> 4 digit are being decoded digitNumber = 8 -> 8 digits are being decoded digitNumber 0 || digitNumber > 8 -> no decoding is being used

func (*Device) SetScanLimit

func (driver *Device) SetScanLimit(digitNumber uint8)

SetScanLimit sets the scan limit. Maximum is 8. Example: a 4 digit 7SegmentDisplay has a scan limit of 4

func (*Device) StartDisplayTest

func (driver *Device) StartDisplayTest()

StartDisplayTest starts a display test.

func (*Device) StartShutdownMode

func (driver *Device) StartShutdownMode()

StartShutdownMode sets the IC into a low power shutdown mode.

func (*Device) StopDisplayTest

func (driver *Device) StopDisplayTest()

StopDisplayTest stops the display test and gets into normal operation mode.

func (*Device) StopShutdownMode

func (driver *Device) StopShutdownMode()

StartShutdownMode sets the IC into normal operation mode.

func (*Device) WriteCommand

func (driver *Device) WriteCommand(register, data byte)

WriteCommand write data to a given register.