Making a flying star effect with LEDs

[lilimike]

I was looking at MIBAM but then moved away due to its limitations:

@ 4Mhz, you can only run 4 LEDs MAX. This can be useful for RGB LED's on small chips.
@ 20Mhz, you can run 20 LEDs since there are more instructions available per period.
@ 48Mhz, you can run 48 LEDs, and anywhere in-between you can have the equivelant number of LEDs to match the OSC frequency.
If you attempt to use too many LEDs for a specific OSC frequency, the program will give a warning to indicate the results will be "Blinky".

I am planing to use 64 LEDs (maybe more) and I am trying to keep the components to minimal.

I haven't figured out if the above limitations apply to MIBAM or BAM. I am still searching for a good BAM explanation.

Mike

[lilimike]

I think I am starting to understand BAM and I am not sure this applies to what I need to do.
Fist I should specify, I indicated in the subject "flying star" as the french that I am but "Shooting star" is more appropriate.
I don't really need to dim any LEDs although it might give an extra quality effect, I only need to turn on and off each LED independently within 64+ LEDs and I was able to do this one by one but failed to have more than one row of LEDs on at the same time.



Mike

[sayzer]

If you are using 64 LEDs via a matrix, then you only need 8 I/O for MIBAM output.

For the video you posted, you need MIBAM.

[lilimike]

I'm trying...

One MIBAM output (B0) going to a resistor then a LED which is then connected to VDD
Using a PIC16F628A with this code the LED remains on with no dimming.

@ __config _INTOSC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_ON & _LVP_OFF & _CP_OFF
clear
DEFINE OSC 8
INCLUDE "MIBAM.pbp"                 ' Mirror Image BAM module                                           

;____[ For 12F/16F only - Interrupt Context save locations]_________________
wsave   var byte    $20     SYSTEM  ' location for W if in bank0
;wsave  var byte    $70     SYSTEM  ' Alternate save location for W 
                                        ' if using $70, comment out wsave1-3
' --- IF any of these next three lines cause an error ?? -------------------
'       Comment them out to fix the problem ----
' -- The chip being used determines which variables are needed -------------
wsave1  VAR BYTE    $A0     SYSTEM      ' location for W if in bank1
wsave2  VAR BYTE    $120    SYSTEM      ' location for W if in bank2
;wsave3 VAR BYTE    $1A0    SYSTEM      ' location for W if in bank3
'---DO NOT change these-----------------------------------------------------
ssave   VAR BYTE    BANK0   SYSTEM      ' location for STATUS register
psave   VAR BYTE    BANK0   SYSTEM      ' location for PCLATH register

TRISB = 000000
PORTB = 0

LED1 VAR byte    

BAM_COUNT   CON 1;      How many BAM Pins are used?
Speed       CON 20;     Smaller = Faster
Brightness  CON 200;    Max DutyCycle


  ASM
BAM_LIST  macro              ; Define PIN's to use for BAM
     BAM_PIN (PORTB,0, LED1)  ; and the associated Duty variables
  endm
  BAM_INIT  BAM_LIST         ; Initialize the Pins
ENDASM


  
Main:
    FOR LED1 = 0 to Brightness -1          ' Ramp up 1 by 1
        PAUSE Speed
    NEXT 

    FOR LED1 = Brightness to 1 STEP -1     ' Ramp down 1 by 1
        PAUSE Speed
    NEXT
GOTO Main

End

What am I doing wrong?

Mike

[lilimike]

I played with the settings and the LED is now dimming.
I am now facing my first issue... how to produce the effect I want.

I will try to find more examples, there's lots of scrolling text but so far I found nothing that resemble what I'm trying to do.
If anyone have a link feel free to share.

Mike

[sayzer]

Try this one.
Pot changes index value for test purposes.
You can have 64 LEDs with this example.
LED corresponding to Index value will turn on.
Playing with this code, you can drive PORTB pins via MIBAM and have lots of effects.

@ __config _HS_OSC & _WDT_OFF & _PWRTE_OFF & _BODEN_OFF & _LVP_OFF & _CP_ALL

CLEAR
DEFINE OSC 20
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTD
DEFINE LCD_RSBIT 5
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 4
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 50

DEFINE ADC_BITS 8      ' Set number of bits in result
DEFINE ADC_CLOCK 3     ' Set clock source (rc = 3)
DEFINE ADC_SAMPLEUS 50 ' Set sampling time in microseconds 
CMCON = 7              ' Disable Comparator & VRef. etc.
pauseus 10
CVRCON = 0
ADCON1 = 96 ' 
100000    Set analog thingie.
ADCON0 = 0              ' All analog, we just need RA0.
TRISA = 255             ' PORTA all input. Others output.
TRISB = 0
TRISC = 0
TRISD = 0
X var PORTB
Y var PORTC
Index var byte
Index2 var byte
OldVal var byte
Pause 10

Begin:
    pause 500
    lcdout $fe,1,"Matrix Test"
    pause 1000
    
    X = 0               
    Y = 255
    
    index = 0
    oldval = 255

Start:
    adcin 0, index      ' Index = max 255.
    index = index / 4   ' To get index values between 0 to 63.
    if oldval <> index then ' Act only when the number changes.
        index2 = index/8    ' X scans 8 bits.
        x = 0               ' turn it Off.
        x.0[index2] = 1     ' Set the bit in line.
        
        y = 255             ' turn all pins on (output is off).
        lookup index2,[7,15,23,31,39,47,55,63],index2   ' Get matrix line.
        y.0[index2-index] = 0                           ' Clear the bit in line (output is on)
    
    
        lcdout $fe,$c0,dec3 index , " ",dec3 index2
        pause 10   
        oldval = index
     endif    

    goto start

end

[lilimike]

I will give this a try.
which PIC are you using? I can't read the text in the picture.

You are using one resistor per column, is it right to say that no matter what, there is only one LED ON at a time?

Thank you for the example, this will help a lot.

Mike

[sayzer]

The example is for 16F877A.
In the example, yes, there is only one LED at a time.