My code has a bug

[Bano310]

My code is blinking, how can I remove this blinking.

this is my code import json from samplebase import SampleBase from rgbmatrix import graphics import RPi.GPIO as GPIO import time import sys

GPIO.setmode(GPIO.BCM) GPIO.setup(21, GPIO.IN) GPIO.setup(24, GPIO.IN) GPIO.setup(18, GPIO.OUT, initial=0)

cont =100 plazas =100 class GraphicsTest(SampleBase): def init(self, *args, **kwargs): super(GraphicsTest, self).init(*args, **kwargs) def run(self): canvas = self.matrix font = graphics.Font() font.LoadFont("../../../fonts/texgyre-27.bdf")

    green = graphics.Color(0, 255, 0)
    graphics.DrawText(canvas, font, 83, 24, green,str(cont))

    blue = graphics.Color(0, 0, 255)
    graphics.DrawText(canvas, font, 1, 23, blue, "plazas")
    time.sleep(1)

while cont <= 100: inputValue = GPIO.input(21) inputValue1 = GPIO.input(24) if (inputValue == True): cont = cont - 1 print("Choche entrada " + str(cont)) time.sleep(.01) class GraphicsTest(SampleBase): def init(self, *args, **kwargs): super(GraphicsTest, self).init(*args, **kwargs) def run(self): canvas = self.matrix font = graphics.Font() font.LoadFont("../../../fonts/texgyre-27.bdf")

            green = graphics.Color(0, 255, 0)
            graphics.DrawText(canvas, font, 83, 24, green,str(cont))

            blue = graphics.Color(0, 0, 255)
            graphics.DrawText(canvas, font, 1, 23, blue, "plazas")
            inputvalue = False
        time.sleep(3)       
time.sleep(1)

if (inputValue1 == True):
    cont = cont + 1
    print("Salida" + str(cont))
    time.sleep(.01)
    class GraphicsTest(SampleBase):
        def __init__(self, *args, **kwargs):
            super(GraphicsTest, self).__init__(*args, **kwargs)
        def run(self):
            canvas = self.matrix
            font = graphics.Font()
            font.LoadFont("../../../fonts/texgyre-27.bdf")
    
            green = graphics.Color(0, 255, 0)
            graphics.DrawText(canvas, font, 83, 24, green,str(cont))

            blue = graphics.Color(0, 0, 255)
            graphics.DrawText(canvas, font, 1, 23, blue, "plazas")
            inputvalue1 = False
        time.sleep(1)       

time.sleep(1)   
if (cont == 0):
    GPIO.output(18, 1)
    print ("parking lleno" +  str(cont))
    class GraphicsTest(SampleBase):
        def __init__(self, *args, **kwargs):
            super(GraphicsTest, self).__init__(*args, **kwargs)
            self.parser.add_argument("-t", "--text", help="The text to scroll on the RGB LED panel")
        def run(self):
            canvas = self.matrix
            font = graphics.Font()
            font.LoadFont("../../../fonts/texgyre-27.bdf")
            LedChain = 4
            
    
            red = graphics.Color(255, 0, 0)
            graphics.DrawText(canvas, font, 0.5, 23, red,"completo")
        time.sleep(.3)
time.sleep(2)

    
if __name__ == "__main__":
    graphics_test = GraphicsTest()
    if (not graphics_test.process()):
        graphics_test.print_help()

time.sleep(5)

https://user-images.githubusercontent.com/101106566/160803942-9fac6711-2991-4e79-9026-ae6df2561a59.mp4

@hzeller @joscarsson @adamwolf @yarikoptic @jwheare @jpoppe

[xuniuer]

Just to remove

time.sleep()

Not necessary to wait, because there is a background thread to update in library.

[Bano310]

@xuniuer hello good I just have to remove the time.sleeps?

[Bano310]

@xuniuer @hzeller import argparse import time import sys import os

sys.path.append(os.path.abspath(os.path.dirname(file) + '/..')) from rgbmatrix import RGBMatrix, RGBMatrixOptions

class SampleBase(object): def init(self, *args, **kwargs): self.parser = argparse.ArgumentParser()

    self.parser.add_argument("-r", "--led-rows", action="store", help="Display rows. 16 for 16x32, 32 for 32x32. Default: 32", default=32, type=int)
    self.parser.add_argument("--led-cols", action="store", help="Panel columns. Typically 32 or 64. (Default: 32)", default=32, type=int)
    self.parser.add_argument("-c", "--led-chain", action="store", help="Daisy-chained boards. Default: 1.", default=1, type=int)
    self.parser.add_argument("-P", "--led-parallel", action="store", help="For Plus-models or RPi2: parallel chains. 1..3. Default: 1", default=1, type=int)
    self.parser.add_argument("-p", "--led-pwm-bits", action="store", help="Bits used for PWM. Something between 1..11. Default: 11", default=11, type=int)
    self.parser.add_argument("-b", "--led-brightness", action="store", help="Sets brightness level. Default: 100. Range: 1..100", default=100, type=int)
    self.parser.add_argument("-m", "--led-gpio-mapping", help="Hardware Mapping: regular, adafruit-hat, adafruit-hat-pwm" , choices=['regular', 'adafruit-hat', 'adafruit-hat-pwm'], type=str)
    self.parser.add_argument("--led-scan-mode", action="store", help="Progressive or interlaced scan. 0 Progressive, 1 Interlaced (default)", default=1, choices=range(2), type=int)
    self.parser.add_argument("--led-pwm-lsb-nanoseconds", action="store", help="Base time-unit for the on-time in the lowest significant bit in nanoseconds. Default: 130", default=130, type=int)
    self.parser.add_argument("--led-show-refresh", action="store_true", help="Shows the current refresh rate of the LED panel")
    self.parser.add_argument("--led-slowdown-gpio", action="store", help="Slow down writing to GPIO. Range: 0..4. Default: 1", default=1, type=int)
    self.parser.add_argument("--led-no-hardware-pulse", action="store", help="Don't use hardware pin-pulse generation")
    self.parser.add_argument("--led-rgb-sequence", action="store", help="Switch if your matrix has led colors swapped. Default: RGB", default="RGB", type=str)
    self.parser.add_argument("--led-pixel-mapper", action="store", help="Apply pixel mappers. e.g \"Rotate:90\"", default="", type=str)
    self.parser.add_argument("--led-row-addr-type", action="store", help="0 = default; 1=AB-addressed panels;2=row direct", default=0, type=int, choices=[0,1,2])
    self.parser.add_argument("--led-multiplexing", action="store", help="Multiplexing type: 0=direct; 1=strip; 2=checker; 3=spiral; 4=ZStripe; 5=ZnMirrorZStripe; 6=coreman; 7=Kaler2Scan; 8=ZStripeUneven (Default: 0)", default=0, type=int)

def usleep(self, value):
    time.sleep(value / 1000000.0)

def run(self):
    print("Running")

def process(self):
    self.args = self.parser.parse_args()

    options = RGBMatrixOptions()

    if self.args.led_gpio_mapping != None:
        options.hardware_mapping = self.args.led_gpio_mapping
    options.rows = self.args.led_rows
    options.cols = self.args.led_cols
    options.chain_length = self.args.led_chain=4
    options.parallel = self.args.led_parallel
    options.row_address_type = self.args.led_row_addr_type
    options.multiplexing = self.args.led_multiplexing
    options.pwm_bits = self.args.led_pwm_bits
    options.brightness = self.args.led_brightness
    options.pwm_lsb_nanoseconds = self.args.led_pwm_lsb_nanoseconds
    options.led_rgb_sequence = self.args.led_rgb_sequence
    options.pixel_mapper_config = self.args.led_pixel_mapper
    
    
    if self.args.led_show_refresh:
      options.show_refresh_rate =1

    if self.args.led_slowdown_gpio !=4 :
        options.gpio_slowdown = self.args.led_slowdown_gpio
    if self.args.led_no_hardware_pulse:
      options.disable_hardware_pulsing = True

    self.matrix = RGBMatrix(options = options)

    try:
        # Start loop
        print("Press CTRL-C to stop sample")
        self.run()
    except KeyboardInterrupt:
        print("Exiting\n")
        sys.exit(0)
    

    return True

This is the library I use could you tell me what part of the library I have to change, to solve the flickering.IT IS VERY URGENT !!!!

THANKS FOR THE USERS WHO HELP.

[xuniuer]

Non-professional suggestions: many factors need to be adjusted or considered against flickering.

1. slowdown gpio value - have a try to adjust the value according to your PI model.
2. enough power provision to board
3. proper wire length - shorter wire length preferred

More details in doc. I remember there are some practical tricks mentioned in the discussion group.

[xuniuer]

Dig more: https://rpi-rgb-led-matrix.discourse.group/t/flicker-when-display-video-with-rpi3b-and-288x128/278/2 this is a good practice.

[Bano310]

Sugerencias no profesionales: muchos factores deben ajustarse o considerarse contra el parpadeo.

1. ralentización del valor de gpio: intente ajustar el valor de acuerdo con su modelo de PI.
2. suministro de energía suficiente para abordar
3. longitud de cable adecuada - se prefiere una longitud de cable más corta

Más detalles en doc. Recuerdo que hay algunos trucos prácticos mencionados en el grupo de discusión.

Hello very good morning(@hzeller @xuniuer ), I think I have not explained well, sorry, I have echo a counter for a parking that subtracts with a button and the other adds, the problem is that the program is always in loop and so blinks just want to start again when you get a signal from any of the buttons and if you have no input pulses to be kept in standby.

I tried to do it only with (IF) removing the (while) but the code did not execute constantly, it read it once and stopped executing.

Greetings from Spain

Thank you very much for your help. @xuniuer

https://user-images.githubusercontent.com/101106566/161912601-0995a687-16d7-4379-b1eb-8c3d56fbd9f7.mp4

https://user-images.githubusercontent.com/101106566/161912605-408bb6ef-93c2-4489-8d9e-a1d25c48961a.mp4

[xuniuer]

Now I understand your problem - when you check a GPIO value then to change content accordingly, it might cause a blink.

My advice is to use gevent which is a micro-thread library instead of builtin thread if Python. The library is more simpler to use and control. The most important, it's light. And, to use wiringpi library to access GPIO.

The following is not complete but has shown how to use gevent and wiringpi libray.

# your_gpio.py
import wiringpi

def gpio_init():
    wiringpi.wiringPiSetup()
    # init your PIN
    # ...

def read_gpio(pin):
    return wiringpi.digitalRead(pin)

def write_gpio(pin, val):
    return wiringpi.digitalWrite(pin, val)

# main.py
import gevent

text = ""
def task_check_gpio():
    global text
    # to change your text here
    while True:
        # to change your text here according your gpio
        gevent.sleep(0.1) # sleep 100ms here then to check again

def task_led_matrix_show():
   global text
   # to show your text
   while True:
      # use RGBMatrix to show contents to screen
      gevent.sleep(0.01)

if __name__ == "__main__":
    tasks = []
    task = gevent.spawn(task_check_gpio)
    tasks.append(task)
    task = gevent.spawn(task_led_matrix_show)
    tasks.append(task)
    gevent.joinall(tasks)