What kind of object is this?

[Moris526]

HI.

Im trying to control a leds color sending data from pc to raspberrypi.
But instead of sending the RGB numbers I want to send a word like PURPLE

If I do this:

PURPLE = (255,0,0)
trellis.color(3,5, PURPLE) # x and y coordinates and color

it works.

But if I send the word PURPLE through serial it doesnt.


is this a string?

PURPLE = (255,0,0)

[ndc85430]

Is what a string? Clearly the variable PURPLE refers to a tuple, not a string. The documentation for whatever library this is should tell you what it accepts. In any case, there's probably a library that will provide variables that refer to their RGB values (but I can't recommend any, I'm afraid).

[Gribouillis]

You could use a dictionary

color_database = {
    "purple1": (155, 48, 255),
    "purple2": (145, 44, 238),
    "purple3": (125, 38, 205),
    "purple4": (85, 26, 139),
}

def rgb(name):
    return color_database[name]

...

treillis.color(3, 5, rgb("purple1"))

On my linux computer, there is the X11 color database at /etc/X11/rgb.txt

[Moris526]

You could use a dictionary

color_database = {
    "purple1": (155, 48, 255),
    "purple2": (145, 44, 238),
    "purple3": (125, 38, 205),
    "purple4": (85, 26, 139),
}

def rgb(name):
    return color_database[name]

...

treillis.color(3, 5, rgb("purple1"))

On my linux computer, there is the X11 color database at /etc/X11/rgb.txt

Yes!!!
Thank you

[deanhystad]

I would write the RGB code. That way you can send any color and the sender and receiver don't need to maintain color dictionaries. I wrote a Python program that prompts for RGB values and writes a string to a file. I wrote a second Python program there periodically reads the RGB values from the file and sets the background of a tkinter window to that color. I used a file because I don't have a serial port.

The program that displays the color:

from tkinter import *

root = Tk()

def check_for_command():
    try:
        with open('color.txt', 'r') as file:
            for line in file:
                r, g, b = map(int, line.split(','))
                root['bg'] = f'#{r:02x}{g:02x}{b:02x}'
    except:
        pass
    root.after(1000, check_for_command)

check_for_command()

root.mainloop()

The program that writes the color information:

r = int(input('Red '))
g = int(input('Green '))
b = int(input('Blue '))
with open('color.txt', 'w') as file:
    file.write(f'{r},{g},{b}')

After I start the display program I can run the write program multiple times and see the changes in the display window.

I could rewrite this program to pass color names. This is the display side that supports tkinter color names:

from tkinter import *

root = Tk()

def check_for_command():
    try:
        with open('color.txt', 'r') as file:
            for line in file:
                root['bg'] = line
    except:
        pass
    root.after(1000, check_for_command)

check_for_command()

root.mainloop()

This is the program that writes the color file:

with open('color.txt', 'w') as file:
    file.write(input('Enter color name ')

[Gribouillis]

You can also load the whole X11 colors dictionary in a few lines

def load_x11_colors(filename='/etc/X11/rgb.txt'):
    with open(filename) as ifh:
        next(ifh)
        L = [line.strip.split() for line in ifh]                                         
    return {' '.join(t[3:]): tuple(int(x) for x in t[:3]) for t in L}                    

color_database = load_x11_colors()