Plasma Effect in MicroPython and Assembly

plasma.py

# plasma
from lcd_1_8 import LCD_1inch8
import machine
from machine import Pin, PWM
from uctypes import addressof
from time import sleep, ticks_us, ticks_diff, ticks_ms
import gc, _thread, array
from sys import exit
from micropython import const
from random import randint
from math import sin,cos,tan,radians,sqrt
from rp2 import bootsel_button as RESET_PB

MAXSCREEN_X = const(160)
MAXSCREEN_Y = const(128)
SCALE       = const(13)

# PLAYER_PARAMS = const(10)
# X  = const(0)
# Y  = const(1)
# VX = const(2)
# VY = const(3)
# AX = const(4)
# AY = const(5)

DARK_GREY  = const(0x4711) #pico_display.create_pen(20, 40, 60)
BLACK      = const(0)      #pico_display.create_pen(0, 0, 0)
DARK_GREEN = const(0x0024) #pico_display.create_pen(32, 128, 0)
LT_BLUE    = const(0x3e44) #pico_display.create_pen(66, 133, 244)
LT_YELLOW  = const(0x33ff) #pico_display.create_pen(255, 229, 153)
LT_GREEN   = const(0xe007) #pico_display.create_pen(0, 255, 0)
BROWN      = const(0xe079) #pico_display.create_pen(120, 63, 4)
WHITE      = const(0xffff) #pico_display.create_pen(255, 255, 255)
SKY_BLUE   = const(0x1f66) #pico_display.create_pen(96, 192, 255)
BLUE       = const(0x1f00)
RED        = const(0xf8)   # rrrrr_gggggg_bbbbb
LT_BROWN   = const(0x52de) # ggg_bbbbb_rrrrr_ggg

GAME_PARAMS = const(10)
FPS = const(0)
LIVES = const(1)
PATTERN = const(2)


char_map=array.array('b',(
     0x3E, 0x63, 0x73, 0x7B, 0x6F, 0x67, 0x3E, 0x00,   # U+0030 (0)
     0x0C, 0x0E, 0x0C, 0x0C, 0x0C, 0x0C, 0x3F, 0x00,   # U+0031 (1)
     0x1E, 0x33, 0x30, 0x1C, 0x06, 0x33, 0x3F, 0x00,   # U+0032 (2)
     0x1E, 0x33, 0x30, 0x1C, 0x30, 0x33, 0x1E, 0x00,   # U+0033 (3)
     0x38, 0x3C, 0x36, 0x33, 0x7F, 0x30, 0x78, 0x00,   # U+0034 (4)
     0x3F, 0x03, 0x1F, 0x30, 0x30, 0x33, 0x1E, 0x00,   # U+0035 (5)
     0x1C, 0x06, 0x03, 0x1F, 0x33, 0x33, 0x1E, 0x00,   # U+0036 (6)
     0x3F, 0x33, 0x30, 0x18, 0x0C, 0x0C, 0x0C, 0x00,   # U+0037 (7)
     0x1E, 0x33, 0x33, 0x1E, 0x33, 0x33, 0x1E, 0x00,   # U+0038 (8)
     0x1E, 0x33, 0x33, 0x3E, 0x30, 0x18, 0x0E, 0x00))  # U+0039 (9)


@micropython.viper
def show_num_viper(num:int,x_offset:int,y_offset:int,color:int):
    char_ptr = ptr8(char_map)
    screen_ptr = ptr16(LCD.buffer)
    size = 1 # 1,2,3
    char = 0
    offset = MAXSCREEN_X*y_offset+x_offset
    while num > 0:
        total = num//10
        digit = num - (total * 10)
        num = total
        for y in range(8):
            row_data = char_ptr[digit*8+y]
            for x in range(8):
                if row_data & (1<<x) > 0:
                    addr = size*y*MAXSCREEN_X+x-(char*8)+offset
                    screen_ptr[addr] = color
                    if size>1:
                        screen_ptr[MAXSCREEN_X+addr] = color
                        if size>2:
                            screen_ptr[2*MAXSCREEN_X+addr] = color
        char += 1


def init_imath():     #integer math scaled 0-360 to 0-256      
    global ISIN,ICOS
    ISIN = array.array('i', int(sin(radians(i* 1.40625)) * (1 << SCALE)) for i in range(256))
    ICOS = array.array('i', int(cos(radians(i* 1.40625)) * (1 << SCALE)) for i in range(256))

def init_pot():
    global POT_X,POT_Y,POT_X_ZERO,POT_Y_ZERO
    POT_X = machine.ADC(27)
    POT_Y = machine.ADC(26)
    POT_X_ZERO = 0
    POT_Y_ZERO = 0
    for i in range(1000):
        POT_X_ZERO += POT_X.read_u16() 
        POT_Y_ZERO += POT_Y.read_u16()
    POT_X_ZERO = POT_X_ZERO//1000
    POT_Y_ZERO = POT_Y_ZERO//1000
    pot_scale = 12 
    

@micropython.viper
def read_pot():
    game = ptr32(GAME)
    pot_scale = 12
    x_inc = int(POT_X.read_u16() - POT_X_ZERO)>>pot_scale
    y_inc = int(POT_Y.read_u16() - POT_Y_ZERO)>>pot_scale
    if x_inc < 2 and x_inc > -2: x_inc=0
    if y_inc < 2 and y_inc > -2: y_inc=0
    if y_inc > 0 and game[PATTERN] < 10<<4:
        game[PATTERN] += 1        
    if y_inc < 0 and game[PATTERN] > 1:
        game[PATTERN] -= 1
    


def init_game():
    global GAME, FPS_ARRY
    GAME = array.array('i',0 for _ in range(GAME_PARAMS))
    FPS_ARRY = bytearray(35)
    GAME[FPS] = 0
    GAME[LIVES]  = 3
    GAME[PATTERN] = 10 << 4

    

MAX_LUT = const(255)
@micropython.viper
def plasma_viper():
    game = ptr32(GAME)
    screen = ptr16(LCD.buffer) # pointer to write to screen memory 160x128, rgb565
    isin = ptr32(ISIN) # pointer to sine table, 0-359 degrees returns sin(radius(deg))*(1<<13)
    icos = ptr32(ICOS) # pointer to cosine table
    pattern = game[PATTERN]>>4
    t = int(ticks_ms())>>5 # get the current time in milliseconds
    for y in range(MAXSCREEN_Y): #128
        for x in range(MAXSCREEN_X): #160   
            # calculate the red, green and blue components using fixed point math and look up tables
            r = 15-((isin[(x + t) & MAX_LUT] + isin[(y + t) & MAX_LUT]) >> pattern) # shift right by 10 to get a value between 0 and 31
            g = 15-((isin[(x - t) & MAX_LUT] + icos[(y + t) & MAX_LUT]) >> pattern)
            b = 15-((icos[(x + t) & MAX_LUT] + isin[(y - t) & MAX_LUT]) >> pattern)
            if r<0: r *= -1
            if g<0: g *= -1
            if b<0: b *= -1
            color = (r<<11) | (g << 5) | b # combine the components into a 16-bit color value
            color_swap = (color ^ (color << 16)) >> 8 # swap the bytes to match the screen format
            screen[y * MAXSCREEN_X + x] = color_swap # write pixel


def init_plasma():
    global PLASMA_ARY
    TIMERAWL = const(0x40054000+0x28)
    PLASMA_ARY = array.array('I',(addressof(LCD.buffer),addressof(ISIN),addressof(ICOS),TIMERAWL,0,0,0,0))


ASM_SCREEN = const(0)
ASM_ISIN   = const(4)
ASM_ICOS   = const(8)
ASM_TIMER  = const(12)
ASM_RED    = const(16)
ASM_BLUE   = const(20)
ASM_GREEN  = const(24)

@micropython.asm_thumb
def plasma_asm(r0):
    ldr(r1,[r0,ASM_TIMER])  # r1 = t
    ldr(r1,[r1,0])
    asr(r1,r1,15)
    mov(r2,0)               # r2 = y
    label(LOOP_Y)
    mov(r3,0)               # r3 = x
    label(LOOP_X)
    #                        r = 15-((isin[(x + t) & MAX_LUT] + isin[(y + t) & MAX_LUT]) >> 10)
    add(r4,r3,r1)           #               x + t
    mov(r5,0xff)
    and_(r4,r5)             #              (x + t) & MAX_LUT
    ldr(r6,[r0,ASM_ISIN])   #         isin[]
    lsl(r4,r4,2)            # x4 for 32-bit
    add(r4,r4,r6)
    ldr(r4,[r4,0])          #         isin[(x + t) & MAX_LUT]
    add(r7,r2,r1)           #                                        (y + t)
    and_(r7,r5)             #                                        (y + t) & MAX_LUT]
    lsl(r7,r7,2)            # x4 for 32-bit
    add(r7,r7,r6)           #
    ldr(r7,[r7,0])
    add(r4,r4,r7)
    asr(r4,r4,10)           # red
    mov(r7,15)
    sub(r4,r7,r4)
    cmp(r4,0)               # check if negative
    bge(RED_POS)
    neg(r4,r4)
    label(RED_POS)
    str(r4,[r0,ASM_RED])
    #                        g = 15-((isin[(x - t) & MAX_LUT] + icos[(y + t) & MAX_LUT]) >> 10)
    sub(r4,r3,r1)           #               x - t
    #mov(r5,0xff)
    and_(r4,r5)             #              (x - t) & MAX_LUT
    #ldr(r6,[r0,ASM_ISIN])  #         isin[]
    lsl(r4,r4,2)            # x4 for 32-bit
    add(r4,r4,r6)
    ldr(r4,[r4,0])          #         isin[(x - t) & MAX_LUT]
    add(r7,r2,r1)           #                                        (y + t)
    and_(r7,r5)             #                                        (y + t) & MAX_LUT]
    ldr(r6,[r0,ASM_ICOS])
    lsl(r7,r7,2)            # x4 for 32-bit
    add(r7,r7,r6)           #
    ldr(r7,[r7,0])
    add(r4,r4,r7)
    asr(r4,r4,10)           # green
    mov(r7,15)
    sub(r4,r7,r4)
    cmp(r4,0)               # check if negative
    bge(GREEN_POS)
    neg(r4,r4)
    label(GREEN_POS)
    str(r4,[r0,ASM_GREEN])
    #                        b = 15-((icos[(x + t) & MAX_LUT] + isin[(y - t) & MAX_LUT]) >> 10)
    add(r4,r3,r1)           #               x + t
    #mov(r5,0xff)
    and_(r4,r5)             #              (x + t) & MAX_LUT
    #ldr(r6,[r0,ASM_ICOS])   #         icos[]
    lsl(r4,r4,2)            # x4 for 32-bit
    add(r4,r4,r6)
    ldr(r4,[r4,0])          #         icos[(x + t) & MAX_LUT]
    sub(r7,r2,r1)           #                                        (y - t)
    and_(r7,r5)             #                                        (y - t) & MAX_LUT]
    ldr(r6,[r0,ASM_ISIN])   #                                   isin[]
    lsl(r7,r7,2)            # x4 for 32-bit
    add(r7,r7,r6)           #
    ldr(r7,[r7,0])
    add(r4,r4,r7)
    asr(r4,r4,10)           # blue
    mov(r7,15)
    sub(r4,r7,r4)
    cmp(r4,0)               # check if negative
    bge(BLUE_POS)
    neg(r4,r4)
    label(BLUE_POS)
    str(r4,[r0,ASM_BLUE])    
    # color = (r<<11) | (g << 5) | b
    ldr(r5,[r0,ASM_RED])
    lsl(r5,r5,11)
    orr(r4,r5)
    ldr(r5,[r0,ASM_GREEN])
    lsl(r5,r5,5)
    orr(r4,r5)
    data(2,0b1011_1010_01_100_100)  # r4=swap color bytes
    mov(r5,160)
    mov(r6,r2)              # y
    mul(r6,r5)              # y * 160
    add(r6,r6,r3)           # y * 160 + x
    add(r6,r6,r6)           # x2 for 16-bit
    ldr(r5,[r0,ASM_SCREEN]) # screen[]
    add(r5,r5,r6)           #
    strh(r4,[r5,0])         # screen[y * 160 + x] = color
    add(r3,r3,1)
    cmp(r3,160)
    blt(LOOP_X)
    add(r2,r2,1)
    cmp(r2,128)
    blt(LOOP_Y)
    label(EXIT)
    

  
@micropython.viper
def draw():
    g = ptr32(GAME)
    LCD.text('FPS',0,0,0xff)
    show_num_viper(g[FPS],20,7,0xff)
    #show_num_viper(gc.mem_free(),40,17,0xff)
    LCD.show()
    LCD.rect(0,0,MAXSCREEN_X,MAXSCREEN_Y,0,1)

@micropython.asm_thumb
def avg_fps_asm(r0,r1): # r0 = fps[] , r1 = current_fps
    ldrb(r2,[r0,0])     # r2 = fps[0]
    add(r2,r2,1)        # fps[0] += 1
    cmp(r2,33)
    blt(LT_32)          # if fps[0] > 32:
    mov(r2,1)
    label(LT_32)
    strb(r2,[r0,0])     # fps[0] = new index
    add(r2,r2,r0)
    strb(r1,[r2,0])     # fps[fps[0]] = current_fps
    mov(r2,1)           # r2 = i
    mov(r3,0)           # r3 = tot
    label(LOOP)
    add(r0,r0,1) 
    ldrb(r4,[r0,0])     # r4 = fps[i]
    add(r3,r3,r4)       # tot += fps[i]
    add(r2,r2,1)
    cmp(r2,33) #33
    blt(LOOP)
    asr(r0,r3,5)

@micropython.viper
def main():
    init_pot()
    init_game()
    init_imath()
    init_plasma()
    g = ptr32(GAME)
    #_thread.start_new_thread(core1, ())
    while not EXIT and not RESET_PB():
        gticks = ticks_ms()
        #sleep(0.001)
        read_pot()
        plasma_viper()
        #plasma_asm(PLASMA_ARY)
        draw()
        g[FPS] = int(avg_fps_asm(FPS_ARRY,1_000//int(ticks_diff(ticks_ms(),gticks))))

def shutdown():
    global EXIT
    EXIT = True
    Pin(16,Pin.OUT).low() # buzzer off
    pwm.deinit()
    Pin(13,Pin.OUT).low() # screen off
    gc.collect()
    print(gc.mem_free())
    print('Core0 Stop')
    exit()    

def core1():
    global PLASMA_ARY
    print(plasma_asm(PLASMA_ARY))
    exit()

if __name__=='__main__':
    FIRE_BUTTON = Pin(22, Pin.IN, Pin.PULL_UP)
    machine.freq(200_000_000)
    machine.mem32[0x40008048] = 1<<11 # enable peri_ctrl clock
    pwm = PWM(Pin(13))
    pwm.freq(10000) #1000
    pwm.duty_u16(0x8fff)#max 0xffff 
    LCD = LCD_1inch8()
    LCD.fill(0)
    LCD.show()
    EXIT = False   
    try:
        main()
        shutdown()
    except KeyboardInterrupt :
        shutdown()

Thanks for all your impressive contributions regarding Pico and LCD displays.
Obviously you are digging very deep into the architecture and accomplishing high performance.

Unfortunately I'm quite new to this and I am searching now for quite some time - without success - for a way to display bitmap files (.bmp or .jpg) on an ILI9488 device.
The thing which seemed closest is: https://www.instructables.com/RPi-Pico-35-Inch-320x480-HVGA-TFT-LCD-ILI9488-Bitm/
but this code simply does not lead to any success on my setup.

Could you please give a hint where to look?

Cheers, W.

That Instructable is very detailed and sounds like just what you need. What exactly is not working? Do you get any errors? First is the wiring, does the Pico plug into the display like a hat or is it discretely wired with jumpers? Did you solder your own headers?Sam On Sep 10, 2023, at 6:32 AM, wayned2 ***@***.***> wrote:Re: ***@***.*** commented on this gist.Thanks for all your impressive contributions regarding Pico and LCD displays.Obviously you are digging very deep into the architecture and accomplishing high performance.Unfortunately I'm quite new to this and I am searching now for quite some time - without success - for a way to display bitmap files (.bmp or .jpg) on an ILI9488 device.The thing which seemed closest is: https://www.instructables.com/RPi-Pico-35-Inch-320x480-HVGA-TFT-LCD-ILI9488-Bitm/but this code simply does not lead to any success on my setup.Could you please give a hint where to look?Cheers, W.—Reply to this email directly, view it on GitHub or unsubscribe.You are receiving this email because you authored the thread.Triage notifications on the go with GitHub Mobile for iOS or Android.                                                           

Thanks a lot for your fast response.

First - strange enough - after working for 1 week on the project and finally asking for help now it is working and can display bitmaps.

What happened when I first tried the code from instructables:
No error messages, just a black screen.

With your code samples everything worked like a charm. (like breakout_3_5.py or LCD_3inch5.py)
So wiring was not the problem.

May I ask what this line (from LCD_3inch5.py) is intended to do ? :
"machine.mem32[0x40008048] = 1<<11 # enable peri_ctrl clock"

Thanks again.

That line goes with machine.freq() When the clock is changed the SPI frequency also changes. This line separates the SPI which drives the LCD from the main clock. Otherwise the display will not work correctly. You if you overclock you may also have to lower the display SPI frequency. I’m not sure why as they should be independent with that line. SamOn Sep 11, 2023, at 12:40 PM, wayned2 ***@***.***> wrote:Re: ***@***.*** commented on this gist.Thanks a lot for your fast response.First - strange enough - after working for 1 week on the project and finally asking for help now it is working and can display bitmaps.What happened when I first tried the code from instructables:No error messages, just a black screen.With your code samples everything worked like a charm. (like breakout_3_5.py or LCD_3inch5.py)So wiring was not the problem.May I ask what this line (from LCD_3inch5.py) is intended to do ? :"machine.mem32[0x40008048] = 1<<11 # enable peri_ctrl clock"Thanks again.—Reply to this email directly, view it on GitHub or unsubscribe.You are receiving this email because you authored the thread.Triage notifications on the go with GitHub Mobile for iOS or Android.                                                           

Thanks a lot again for these insights.

Good luck with your great projects.