index :: hw

hw.rpi.spi.max7219

LED matrix driver based on max7219 chip for Raspberry Pi

available since version: 0.9.8

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information

Only Raspberry Pi support Handles communication with the MAX7219 chip for 7-segmented or 8x8 LED dot matrix displays. Each display can be connected in series with another and controlled via a single connection. Note: in case of LED dot matrix display only write_bits and write_reg commands will work as expected Note: 7-segment LED display supports only this charset: -_0123456789ABCDEFGHIJLOPSUbcdhnoqrtu Note: if the device address argument is -1 or omitted, requested action is applied for all devices in a chain.

arguments:

• DISPLAYS number of displays connected into chain
  type: int
  

methods:

• clear clear display
  parameters:
  • [ADDR=0] display address in chain
    type: int
    
• intensity set intensity level on the display
  parameters:

  • LEVEL intensity level
    type: int
    required: True
    

  • [ADDR=-1] target display address in the chain
    type: int
    

• power power on/off display
  parameters:
  • STATE on/off state
    type: bool
    required: True
    
• test test display by turning all led on
  parameters:
  • [ADDR=-1] target display address in the chain
    type: int
    
• write bits write raw bits into the display
  parameters:

  • ADDR=0 target display address in the chain
    type: int
    required: True
    

  • BITS list of bits. Max length: 256
    type: list
    required: True
    

• write bytes write raw bytes into the display
  parameters:

  • ADDR=0 target display address in the chain
    type: int
    required: True
    

  • DATA list of bytes. Max length: 8
    type: list
    required: True
    

• write float write float value into 7-segment display (no led matrix support!)
  parameters:

  • VAL value
    type: float
    required: True
    

  • [PRECISION] precision after the dot
    type: int
    

  • [ADDR] display address in the chain. If omitted or -1: write to all displays
    type: int
    

• write hex write hex unsigned integer value into 7-segment display (no led matrix support!)
  parameters:

  • INT value
    type: int
    required: True
    

  • [ADDR=0] display address in the chain
    type: int
    

• write int write signed integer value into 7-segment display (no led matrix support!)
  parameters:

  • INT value
    type: int
    required: True
    

  • [ADDR] display address in the chain. If omitted or -1: write to all displays
    type: int
    

• write reg write the max7219 register data. Lowest level of communication
  parameters:

  • REG max7219 register index
    type: int
    required: True
    

  • DATA the register value
    type: int
    required: True
    

  • [ADDR=0] target display address in the chain
    type: int
    

• write str write string into 7-segment display (no led matrix support!)
  parameters:

  • STR string. maxlength: 8 chars
    type: symbol
    required: True
    

  • [DOTS] dots as bit value. For ex.: 0b00000011 turn on a two leftmost dots
    type: int
    

  • [ALIGN=right] string align
    type: symbol
    

  • [ADDR=0] display address in the chain
    type: int
    

properties:

• @cs (initonly) Get/set CS (ChipSelect, SlaveSelect or ChipEnable) index
  type: int
  range: 0..3
  default: 0
  

• @displays (initonly) Get/set number of displays connected into the chain
  type: int
  range: 1..8
  default: 1
  

• @spi (initonly) Get/set SPI bus number.
  type: int
  range: 0..6
  default: 0
  

inlets:

• control input
  type: control

keywords:

led display max7219 spi rpi arduino

Authors: Serge Poltavsky

License: GPL3 or later