Using GCB with Generic MAX7219 Module and Arduino Nano

[Awais]

I am trying to use Generic MAX7219 8x8 Dot Matrix module with GCB and Arduino Nano 328P. After using the example file, the following are the observations.

1. Display is 90 degree rotated with reference to IC.
2. The message starts on the farthest module from Arduino Nano.

YouTube video link is here https://youtu.be/9t5RB3dxJD4
Any solution to this issue or any guidance how to change the library files to adopt this module?

Thanks and regards,
Awais

[Anobium]

Hello

When I wrote the library, I guessed but did not know, that these Matrixes would be upside down.

Add this to your user program. This should rotate the matrix.

#define Pset max7219_LEDMatrix_PSet_90

Once we have the matrix the correct way around we can adapt for write direction.

[Awais]

Thank you. Now, text is scrolling correctly. But in my hardware design the text should be upside down. So, the command should be something similar to

define Pset max7219_LEDMatrix_PSet_270

and the first module connected to Nano is the first from right hand side. So, text scrolling should be from right to left.

YouTube video link is here https://youtu.be/A6L7K7WLLnU

[Anobium]

I am being dim? but, just rotate the matrix... or, am I missing something?

[Awais]

You are right. That is one solution but there are other concerns due to which I cannot rotate it.

[Anobium]

As a test, as I have NOT tested. Do exactly the following:

Add the is code unchanged to your program.

If this works then I can explain later.

  #define Max7219_LEDMatrix_ScrollMessage Max7219_LEDMatrix_ScrollMessageOut


  Sub Max7219_LEDMatrix_ScrollMessageOut( in OutMessage as string, In max7219_MessageTime As Word )

    dim max7219_ScrollLen, max7219_ScrollPosition, max7219_XScrollPosition as word
    max7219_ScrollLen = OutMessage(0) * GLCDFontWidth

    max7219_XScrollPosition = 0'Max7219_PixelBytes-1

    For max7219_ScrollPosition = 0 to max7219_ScrollLen-1
      Max7219_LEDMatrix_ClearBuffer ( Max7219_Image_Buffer() ,Max7219_PixelBytes)
      GLCDPrint(max7219_XScrollPosition, 0,  OutMessage)
      max7219_XScrollPosition++
      Max7219_LEDMatrix_SendBuffer ( Max7219_Image_Buffer() ,Max7219_PixelBytes)
      if max7219_MessageTime > 0 then
          Wait max7219_MessageTime ms
      end if
    Next

  End Sub

[Anobium]

I have posted a revised method. This shows the basic left to right scroll. My first attempt failed. :-(

The original library was based on a right to left scroll that is used on the UK train system. :-)

To understand. Think of the matrix as a set of pixel, they are stored in memory. The pixels are updated using the GLCD command set. Then, the methods set the memory to the display.

You should be able to change the library to do a lot more than I have in the library.

Anobium

[Awais]

Yes, the message should scroll from right to left but I am surprised that why it is from left to right in my hardware (right one is the first module which is connected to Arduino). I tested Parola library for Arduino and its ok but there are issues of consistency. But with GCB its good. The system is running fine. Now, the orientation and scrolling direction have to be controlled. I will try to understand the routines to tune it for the requirements.

Please update here if you come up with the solution.

Thanks and regards,
Awais

[Anobium]

I would look at PSET. The PSET updates the internal memory array, the other routines then send the memory array to the matrixes.

The matrixes are so differernt. I have learnt this recently. Some are left to right, up and down and other dont work.

So, look at PSET - this updates memory array then adapt the routines that update the devices... with respect to direction. Sounds so easy.

[Awais]

Demo video using GCB, Arduino Nano, Dot Matrix Display with MAX7219, DS3231 and DHT22
https://www.youtube.com/watch?v=yEiVToSmaUA

[Anobium]

Very nice!

[Anobium]

Post the project code! Lots of folks are interested.

[Awais]

Thanks for your comments. Here is the code. Please add this to demo codes in next release of GCB.

'''A demonstration program for Great Cow Basic.
'''--------------------------------------------------------------------------------------------------------------------------------
'''This program shows Time, Date, Temperature and Humidity on MAX7219 Dot Matrix Display using Arduino Nano, DS3231 and DHT22.
'''Credit goes to Great Cow Basic Team
'''@author  Owais Najam
'''@licence GPL
'''@version 1.0
'''@date 6th Dec 2018
''' There is always room for improvement.
'''********************************************************************************

; ----- Configuration
  #chip mega328p, 16
  #config MCLRE=on
  #include <max7219_ledmatrix_driver.h>
  #include <dht.h>
  #include <ds3231.h>
  #include <i2ceeprom.h>                  ; memory chips: at24c32 (storage capacity 32k)
  #option Explicit

  #define    AT24C32  0xAE                  ;Eeprom address

; Define Hardware I2C settings
  #define HI2C_BAUD_RATE 100
  #define HI2C_DATA PORTC.4
  #define HI2C_CLOCK PORTC.5
  HI2CMode Master


; ----- Constants
  #define DHT_type    22
  #define DHT_PIN PORTD.2

  #define period      2 S             ;update period

  #define clocktype   1               ;0 is US or 1 is UK style


; ----- Constants
  'Set SPI pins for the Max7219
  #define Max7219_DI    portb.4    'pin12
  #define Max7219_DO    portb.3    'pin11
  #define Max7219_SCK   portb.5    'pin13
  #define Max7219_CS    portb.2    'pin10

  'Specifics for device configuration
  #define MAX7219_X_Devices 8

  Dim ALARM1TRACK, ALARM2TRACK as Byte
  Dim CENTURY_FLAG, POWERLOSS, EEPROMVAL, DAYSMAX, DAYSMAX as Byte
  dim changed as bit
  dim hour, min, sec, am_pm as byte
  dim oldsec as byte
  dim date, month, year, DOW, century as byte
  dim mode, Oldmode, dayMax as byte
  oldsec = 255                        ; init value
  century = 20                        ; will be updated by Century calculation... if a century roll ever occurs!! Required in this example code.

  dim myString as string * 50
  Max7219_LEDMatrix_Brightness ( 0 )

;----- Tables

  table monthDays                     ;# of days in months. Required in this example code.
    31
    29                                ;leap years only
    31
    30
    31
    30
    31
    31
    30
    31
    30
    31
  end table


'; ----- Main body of program commences here.




; ----- Define Hardware settings


; ----- Variables

  'required for DHT
  dim msg, whole, tenths as byte
  dim rh, cels, fahr as integer

; ----- Quick Command Reference:
;       The humidity and temperatures are signed integers, the error
;       indicator a byte. For the DHT11, the numerical results are
;       simply whole numbers. For the DHT22 numerical results
;       are fixed pointed numbers, with the decimal point assumed one
;       digit from the right. In other words, the values are scaled up
;       by 10. For example, a return value of 657 for the relative
;       humidity would be interpreted as 65.7%.

; ----- Main body of program commences here.

  GLCDCLS
  GLCDPrint (1, 0, "Wait...")
  Max7219_LEDMatrix_Update
  'let sensor stabilize
  wait period

  #ifdef HI2C_DATA
        ' GLCDCLS
        ' GLCDPrint (1, 0, "i2cHW" )
        ' Max7219_LEDMatrix_Update
        ' wait period
        HI2CReStart                          ; is DS3231 present?
        HI2CSend(DS_AddrWrite)
        HI2CStop

        if HI2CAckPollState = True  then  ; is DS3231 present?
            GLCDCLS
            GLCDPrint (1, 0, "No DS3231.." )
            Max7219_LEDMatrix_Update
            wait period
            end
        end if
  #endif

  #ifdef I2C_DATA
        ' GLCDCLS
        ' GLCDPrint (1, 0, "i2cSW" )
        ' Max7219_LEDMatrix_Update
        ' wait period
        I2CStart                          ; is DS3231 present?
        I2CSend(DS_AddrWrite)
        I2CStop

        if I2CSendState = False  then     ; is DS3231 present?
            GLCDCLS
            GLCDPrint (1, 0, "No DS3231.." )
            Max7219_LEDMatrix_Update
            wait period
            end
        end if
   #endif


  DS3231_ReadDate(DOW, date, month, year, century_flag )   ;get initial date
  if century_flag = 1 then
     DS3231_HandleCentury ( century_flag, Century )
  end if

  DS3231_ReadHourMode(mode)                 ;and the current mode
  DS3231_SetHourMode(12)                  ;update hour mode from RTC
  DS3231_EnableOscillator( true )           ;and, ensure the clock is running

  ;
  ;Example of configuration of the 32K output and the SQW
  ;
  DS3231_Set32kHz ( true )                  ;and, enable the 32kHz Output (EN32kHz).
  DS3231_EnableSQW
  DS3231_SetSQW 0                           ;and, turn ON output as we will use as the alarm port!
  DS3231_DisableSQW




  do

      DS3231_ReadDate(DOW, date, month, year, century_flag )   ;get initial date. This is required for main routine.
      if century_flag = 1 then
        DS3231_HandleCentury ( century_flag, Century )
      end if

      DS3231_ReadHourMode(mode)                 ;and the current mode

      ' initialise a tracking varaible
      powerloss = false
      dim EEpromAddress as word
      EEpromAddress = 0

      GLCDCLS
      updateDisp                        ;show time and date

      wait period

        'get current values
        readDHT(rh, cels, fahr, msg)
        GLCDCLS
        select case msg
          'all okay, so proceed
          case 0:
            rh = rh / 10
            cels = cels / 10
            fahr = fahr / 10
            myString = str(cels) + "/"
            myString = myString + str(fahr) + " "
            myString = myString + str(rh) + "%"
            GLCDPrint (5, 0, myString )
            Max7219_LEDMatrix_Update
          'unit not responding
          case 1:
            GLCDPrint (1, 0, "No reply...")
            Max7219_LEDMatrix_Update
          'checksum error
          case 2:
            GLCDPrint (1, 0, "Bad CS...")
            Max7219_LEDMatrix_Update
        end select

        wait period
  loop
  end

  sub printTime
    myString = ""
    'if mode = 24 then
      if hour < 10 then               ;left pad with zero
        myString = "0"
      end if
    'end if
    myString = myString + str(hour)
    myString = myString + ":"

    if min < 10 then                  ;left pad with zero
      myString = myString + "0"
    end if
    myString = myString + str(min)
    myString = myString + ":"

    if sec < 10 then                  ;left pad with zero
      myString = myString + "0"
    end if
    myString = myString + str(sec)

    if mode = 12 then                 ;Print a.m or p.m
      if am_pm then                   ;only in 12-hour mode
        myString = myString + "pm"
        GLCDPrint (2, 0, myString )
        Max7219_LEDMatrix_Update
      else
        myString = myString + "am"
        GLCDPrint (2, 0, myString )
        Max7219_LEDMatrix_Update
      end if
    end if
  end sub


sub printDate
    myString = ""
    select case DOW                   ;day of the week
      case 1:
        myString = "Sun"
      case 2:
        myString = "Mon"
      case 3:
        myString = "Tue"
      case 4:
        myString = "Wed"
      case 5:
        myString = "Thu"
      case 6:
        myString = "Fri"
      case 7:
        myString = "Sat"
      case else
        myString = "Err"
    end select

    myString = ""
    if clocktype = 0 then
      myString = myString + str(month)
      myString = myString + "/"

      if date < 10 then                  ;left pad with zero
        myString = myString + "0"
      end if

      myString = myString + str(date)
      myString = myString + "/"                      ;make four-digit year
      myString = myString + str(century)
      if year < 10 then
        myString = myString + "0"
      end if

    else
      if date < 10 then                  ;left pad with zero
        myString = myString + "0"
      end if

      myString = myString + str(date)
      myString = myString + "/"
      myString = myString + str(month)
      myString = myString + "/"                      ;make four-digit year
      myString = myString + str(century)
      if year < 10 then
        myString = myString + "0"
      end if
    end if
    myString = myString + str(year)

    GLCDPrint (2, 0, myString )
    Max7219_LEDMatrix_Update
  end sub


  sub updateDisp
    ;for best efficiency, date is only updated once a day
    DS3231_ReadTime(hour, min, sec, am_pm)
    if oldsec <> sec then
      if !(hour | min | sec) then       ;time to update
        DS3231_ReadDate(DOW, date, month, year, century_flag )
        if century_flag = 1 then
           DS3231_HandleCentury ( century_flag, Century )
        end if
      end if

      printTime                         ;show time
      wait period

      GLCDCLS
      printDate
      oldsec =  sec
    end if
  end sub

Waiting for some more twists from the coding fellows.

With kind regards,
Awais

[Anobium]

What a good idea!

See https://github.com/Anobium/Great-Cow-BASIC-Demonstration-Sources/tree/master/LED_Matrix_Solutions/Completed_working_projects

[Awais]

Once again, thank you for your prompt consideration.

One question, how can I edit the fonts or you can say alter the alphabets?

[Anobium]

Pleasure, good to see someone using the software.

As this is using the GLCD command set - you are using the GLCD fonts.

I posted a demo how to do this. See you installation - ..\Demos\GLCD_Solutions\GLCD_Demonstration_of_adding_additional_Font_Solutions\GLCD_Adding_an_second_Font_16F886_for_KS0108@16.gcb

The method is the same - essentially replace GLCDDrawChar with your routine and your tables - then you can edit away to your hearts content. :-)

Leave glcd.h and the other .h files as is... use the method shown in the demo. It is SO easy to loose adapted .h files and using the method shown in the demo ensure your do not loose your good works.

[Awais]

Thanks. I will check.

[stan cartwright]

I ordered 2 .... https://www.ebay.co.uk/itm/MAX7219-Microcontroller-4-In-One-Display-Module-For-Arduino-5P-Line-Dot-Matrix/292804189269?epid=1994378909&hash=item442c7d5c55:g:jEcAAOSwIGxb4A~W:rk:11:pf:0
As said ..they're not all the same but will see.
Thanks for doing the hard work. I use arduino more than pic so useful code.
Maybe one day ebay will say "works with gcband arduino", as more hardware is included.
I orderded 2 to see if a 16x32 dot addressable display was possible.

[Awais]

You are welcome. Now, I want to put degree "°" sign with C or F as per preference, e.g. 25°C 75%. Will anyone come with the solution?
Check aliexpress.com also https://www.aliexpress.com/wholesale?spm=2114.search0104.8.32.2e736d36jK7b9r&initiative_id=QRW_20181207234535&SearchText=max7219+display+module&productId=32880754577
Sometimes cheaper than ebay and "Buyer Protection" https://sale.aliexpress.com/__pc/BhQPgEWPNM.htm?spm=2114.search0104.7.1.1d97718c1vfVRh

[Awais]

I didn't search the entire forum. Just found this utility "8x8 Pixel ROM Font Editor".
https://www.min.at/prinz/o/software/pixelfont/

[Anobium]

Regarding the degree "°" sign. I would not change the font. Simply pset the character out. So, pset the character out at the appropiate location using a table of the bits.

[Awais]

I did the following changes.

dim xposition_degreesymbol as Byte
|
|
|
case 0:
            rh = rh / 10
            cels = cels / 10
            fahr = fahr / 10

            myString = ""

            if cels < 10 then               ;left pad with zero
              myString = "0"
            end if

            myString = myString + str(cels) + " C "
            'xposition = (length_of_mystring - 3) * 5 + 8 + 3
            xposition_degreesymbol = Len(myString)
            xposition_degreesymbol = xposition_degreesymbol - 3
            xposition_degreesymbol = xposition_degreesymbol * 5
            xposition_degreesymbol = xposition_degreesymbol + 11
            'myString = str(cels) + "/"
            'myString = myString + str(fahr) + " "
            myString = myString + str(rh) + "%"
            'GLCDPrint (5, 0, myString )
            GLCDPrint (8, 0, myString )


            ' Print degree symbol
            PSet(xposition_degreesymbol, 1, 1)
            PSet(xposition_degreesymbol, 2, 1)
            PSet(xposition_degreesymbol + 1, 0, 1)
            PSet(xposition_degreesymbol + 2, 0, 1)
            PSet(xposition_degreesymbol + 1, 3, 1)
            PSet(xposition_degreesymbol + 2, 3, 1)
            PSet(xposition_degreesymbol + 3, 1, 1)
            PSet(xposition_degreesymbol + 3, 2, 1)

            Max7219_LEDMatrix_Update

And it's working.

Thanks and regards,
Awais

[stan cartwright]

I suppose the font table used has a start address so 8 bytes per char, find start of char to change and design on paper and each pixel in a row is a bit.
I'm guessing. I looked at glcd and #ifdef GLCD_OLED_FONT
CharCode = CharCode - 16
ReadTable OLEDFont1Index, CharCode, LocalCharCode
ReadTable OLEDFont1Data, LocalCharCode , COLSperfont
I would want to change all the chars to user designed graphics, there's plenty of program memory and ram to read a table into ram.

[Anobium]

That is not way I would do it. As I am not guess.

GLCD_OLED_FONT = 1 this reads the tables called OLEDFont1Index and OLEDFont1Data. Replacing this is one way.

The real way - and the one that want to do is here: http://oleddisplay.squix.ch/#/home There is NOT reason why a simple converter could not read this font table and use the define fontset. With a simple converter any font could be used with this utility.

[stan cartwright]

Since I have a few displays that have gcb support I should have already tried udgs but...etc.
I last changed a charset on a sinclair or amstrad but I suppose it's the same idea.
The char set was in rom but there was an address you could change to point to ram so you designed another char set in ram. So print "a" would print the "a" in ram.
Is this the basic idea using gcb. Ie the char set is stored somewhere and the start is known, each char is 8 rows of 1 byte and each byte represents 8 pixels/leds?
Is connecting two displays to use as a 16x32 possible with gcb...or any system?
Cheers.