Bit Angle Modulation (BAM) in a PIC

[sanch0]

because u can share ur code.

so i say the secret,haha.

we can get A[0],A[1],,,A[13].

then

move A[1] to W.

then

movff A[0], PORTA
movwf PORTA

then we changer the H/L in a cycle.

have a good time.

haha.

Yep=)))
It's something like that.


btw, i had got my first shocks from electronics when i tryed to understand how my photoflash works. There was ~1000V on capacitor after trafo, but it didn't scare me) i was 5 years old then)

[lanyong]

Yep=)))
It's something like that.


btw, i had got my first shocks from electronics mosquitowhen i tryed to understand how my photoflash works. There was ~1000V on capacitor after trafo, but it didn't scare me) i was 5 years old then)

but it is a secret for me.

we can use the 1000v to electronic mosquito,

[Mike, K8LH]

Darrel,

I think these Gentlemen may be having a little fun at your expense as they try to get a rise out of you (LOL). That's the only reason I can think of for avoiding a simple question and for becoming a bit offensive when challenged.

My precalculated "output table" or "toggle table" MIBAM method should work fine with 13 or 14 bit duty cycle values but as you've already determined I can only get refresh rates of 610-Hz (8-chan, 13-bit, 200-nsec step) or 305-Hz (16-chan, 13-bit, 400-nsec step), etc., when using an 18F' device and 40-MHz clock (Tcy = 100-nsec). ISR "overhead" would be about 77% for the example below but could be improved with some structural changes.

Take care. Kind regards, Mike

;
;  8-chan (port b), 13-bit, 200-nsec (1638.4-usec period), 610-Hz
;
v_isr_h
        movff   bdat+12,LATB    ; b12 data        (2048T)
        inDlyCy(2048*tStep-2)   ; half 2^12
        movff   bdat+11,LATB    ; b11 data        (1024T)
        inDlyCy(1024*tStep-2)   ; half 2^11
        movff   bdat+10,LATB    ; b10 data        (512T)
        inDlyCy(512*tStep-2)    ; half 2^10
        movff   bdat+09,LATB    ; b9 data         (256T)
        inDlyCy(256*tStep-2)    ; half 2^9
        movff   bdat+08,LATB    ; b8 data         (128T)
        inDlyCy(128*tStep-2)    ; half 2^8
        movff   bdat+07,LATB    ; b7 data         (64T)
        inDlyCy(64*tStep-2)     ; half 2^7
        movff   bdat+06,LATB    ; b6 data         (32T)
        inDlyCy(32*tStep-2)     ; half 2^6
        movff   bdat+05,LATB    ; b5 data         (16T)
        inDlyCy(16*tStep-2)     ; half 2^5
        movff   bdat+04,LATB    ; b4 data         (8T)
        inDlyCy(8*tStep-2)      ; half 2^4
        movff   bdat+03,LATB    ; b3 data         (4T)
        inDlyCy(4*tStep-2)      ; half 2^3
        movff   bdat+02,LATB    ; b2 data         (2T)
        inDlyCy(2*tStep-2)      ; half 2^2
        movff   bdat+01,LATB    ; b1 data         (1T)
        inDlyCy(1*tStep-2)      ; half 2^1 (0 delay)
        movff   bdat+00,LATB    ; b0 data         (1T)
        inDlyCy(1*tStep-2)      ; full 2^0 (0 delay)
        movff   bdat+01,LATB    ; b1 data         (1T)
        inDlyCy(1*tStep-2)      ; half 2^1 (0 delay)
        movff   bdat+02,LATB    ; b2 data         (2T)
        inDlyCy(2*tStep-2)      ; half 2^2
        movff   bdat+03,LATB    ; b3 data         (4T)
        inDlyCy(4*tStep-2)      ; half 2^3
        movff   bdat+04,LATB    ; b4 data         (8T)
        inDlyCy(8*tStep-2)      ; half 2^4
        movff   bdat+05,LATB    ; b5 data         (16T)
        inDlyCy(16*tStep-2)     ; half 2^5
        movff   bdat+06,LATB    ; b6 data         (32T)
        inDlyCy(32*tStep-2)     ; half 2^6
        movff   bdat+07,LATB    ; b7 data         (64T)
        inDlyCy(64*tStep-2)     ; half 2^7
        movff   bdat+08,LATB    ; b8 data         (128T)
        inDlyCy(128*tStep-2)    ; half 2^8
        movff   bdat+09,LATB    ; b9 data         (256T)
        inDlyCy(256*tStep-2)    ; half 2^9
        movff   bdat+10,LATB    ; b10 data        (512T)
        inDlyCy(512*tStep-2)    ; half 2^10
        movff   bdat+11,LATB    ; b11 data        (1024T)
        inDlyCy(1024*tStep-802) ; half 2^11
        rcall   prep            ; rebuild bdat array
        movff   btmp,LATB       ; b12 data        (2048T)
        retfie  FAST            ;
;

[Darrel Taylor]

Thanks for the Backup Mike.
It's nice to see somebody else gets the same numbers.

I'm making some progress with the "full-port" modification to MIBAM.

Actually doing the outputs is easy, just like you showed previously.
But I'm still having problems letting the user assign pins at random.

It's getting there, although a bit slower than anticipated.
<br>

[sanch0]

Thanks for the Backup Mike.
It's nice to see somebody else gets the same numbers.

I'm making some progress with the "full-port" modification to MIBAM.

Actually doing the outputs is easy, just like you showed previously.
But I'm still having problems letting the user assign pins at random.

It's getting there, although a bit slower than anticipated.
<br>

that's nice, but not so effective at all. interleaving could be used to get more channels at the same freq. and something else to get 100ns discretization.)))

[boroko]

Hi all,
I had a question that seems to have gotten lost in the fray....

I'm trying to use other interrupts in hardware functions while using MIBAM.
Specifically, a CCP HI/LO capture or USUART. the stand alone MIBAM examples work wonderfully, but when I try and incorporate a lo priority pulse capture or do comm, I run into problems. Is there a way to use incorporate the other ints and still use MIBAM? I have resorted to using a second PIC, but that isn't very elegant.

Thanks for thinking about it.
Bo

[Darrel Taylor]

Hi Bo,

If you're using an 18F, then sure ... you can have Low Priority interrupts running too. But I don't think you need interrupts for that stuff.

With MIBAM ... <strike>99.4%</strike> 94% of the processor time is un-used. It's just sitting around twiddling it's thumbs. (if it has any)

And since "capture's" retain the captured value for a while, they can easily be handled in the main loop by polling the CCPIF flag.

I've also run the USART at 250kbaud for DMX reception, again strictly polled in the main loop, while MIBAM runs in the background.

So much time ... so few things to do ... if only life were like that.
<br>

[JimAvanti]

I notice this is an old thread (Starting in 2009 with the last post in 2011). I downloaded Darrel Taylor's BIBAM ver 1.1 and had it working great with a 16f690.
I am now trying it on a 18f14k22 and I can't get it working at all. From what I am reading it should work with the 18F's. I am trying to control 9 outputs (3 RGB LEDs). The 16f690 is too slow @8MHz

Does anyone know if there are any issues using this with the 18f14k22 or if there is an updated BIBAM available?
I am getting assembly errors when I try to compile: Symbol not previously defines (_VarIn), Missing arguments.

Jim

[Darrel Taylor]

Hi Jim,

It should work with the 14K22.

That error can only be generated by a BAM_PIN statement.

Make sure it looks something like this ...

BAM_PIN (PORTB,0, Duty1)

Note the comma between PORTB and 0.
Duty1 should be a BYTE var.

Make sure the designated pins are available.
The 14K22 only has RA0-RA5, RB4-RB7 and RC0-RC7