pythonlinuxtkinterraspberry-pi

Python: How to convert a rgb or hex value to single color values

I am making a Python script with a GUI using Tkinter to control LED strips with a Raspberry Pi. The strips are connected to mosfets and they connect to the GPIO ports.

So far I have: a GUI with on/off buttons for each channel, this starts or stops the pwm output. I have a slider (scale) coupled to a entry box in which the pwm value is changed from 0 to 100, you can move the slider or type in a value in the entry box and they both change when changing one. this also automatically updates the outputs DutyCycle from 0 to 100 so you can completely dim a channel's color in 100 steps and see it dim as you move the slider.

Now i have used the Tkinter.colorchooser module to add a button to let me pick a color with the build in colorpicker. When i pick a color, the module returns a tuple consisting of the rgb values and a hex value, what looks like this:

{214.8359375 215.83984375 214.8359375} #d6d7d6

I am able to take only the rgb triple or only the hex value and put it in a variable but here's where I am stuck.

My pwm circuit uses a 0-100 value without decimals. so I started with getting just the rgb triple and divided its value by 255 and multiply by 100 to give me a 0-255 to 0-100 conversion. but it still has a lot of decimals which I don't need/want. and the 3 color value's are just separated by spaces.

Now how can I take that triple and convert it into 3 separate variables without decimals so I can put each variable in its desired entry box and make the slider move and change the leds dutycycle.

I've tried splitting the tuple but it gives me something like it expected less values, but I think that is because the tuple doesn't have commas

Would it be easier to take the hex value and convert it to separate values? I hope that anyone can help me with this, I'm a little stuck right now.

Thank you.

Update:

def pickcolor1():
    (triple1,hexstr1) = askcolor(initialcolor='#000000')
    if triple1:
        triple1pwm = [x / 255.0 * 100 for x in triple1]
        colorlabel1 = Label(mGui,text=triple1pwm).grid(row=14,column=0,columnspan=34)
pickcolorbutton1 = Button(mGui,text='Pick color',width=1,command=pickcolor1).grid(row=13,column=1,columnspan=4,sticky=W+E)

With all sliders of the colorpicker to 0 it gives this: [0.0, 0.0, 0.0]

So I also need to remove the brackets? [ ]

with all sliders to 255 it gives: [100.390625, 100.390625, 100.390625]

Update2:

I have the values separated and put into different labels, later that will be entryboxes

def pickcolor1():
    (triple1,hexstr1) = askcolor(initialcolor='#000000')
    if triple1:
        triple1pwm = [x / 255.0 * 100 for x in triple1]
        colorlabelr1 = Label(mGui,text=triple1pwm[0]).grid(row=14,column=0,columnspan=34)
        colorlabelg1 = Label(mGui,text=triple1pwm[1]).grid(row=15,column=0,columnspan=34)
        colorlabelb1 = Label(mGui,text=triple1pwm[2]).grid(row=16,column=0,columnspan=34)
        print(triple1pwm[0])
        print(triple1pwm[1])
        print(triple1pwm[2])
pickcolorbutton1 = Button(mGui,text='Pick color',width=1,command=pickcolor1).grid(row=13,column=1,columnspan=4,sticky=W+E)

This works now only need to round it down

Update3:

Now rounded each value down and put it into a entry box, still has the .0 after the value.

def pickcolor1():
    (triple1,hexstr1) = askcolor(initialcolor='#000000')
    if triple1:
        triplepwm1 = [x // 2.55 for x in triple1]
        pwmr1 = StringVar()
        pwmg1 = StringVar()
        pwmb1 = StringVar()
        pwmr1.set(triplepwm1[0])
        pwmg1.set(triplepwm1[1])
        pwmb1.set(triplepwm1[2])
        pickentryr1 = Entry(mGui,textvariable=pwmr1).grid(row=14,column=0,columnspan=34)
        pickentryg1 = Entry(mGui,textvariable=pwmg1).grid(row=15,column=0,columnspan=34)
        pickentryb1 = Entry(mGui,textvariable=pwmb1).grid(row=16,column=0,columnspan=34)
        print(triplepwm1[0])
        print(triplepwm1[1])
        print(triplepwm1[2])
pickbutton1 = Button(mGui,text='Pick color',width=1,command=pickcolor1).grid(row=13,column=1,columnspan=4,sticky=W+E)
Solution

  • with all sliders to 255 it gives: [100.390625, 100.390625, 100.390625]

    This is an artifact of the print command. It means that you have a list with three values in the list.

    If you print the three variable in one line, you will get three values separated by spaces

    >>> print r, g, b
100.390625 100.390625 100.390625

    Your math is forcing the values of the list to floating point. You want it as integers. When you round it down, you are placing the integer values into floating point variables which would still output with the final .0 Change

    triple1pwm = [x / 255.0 * 100 for x in triple1]

    to

    triple1pwm = [int(x*100/255) for x in triple1]

    This will round down to the integer value.

    You can also use 

    triple1pwm = [x*100//255 for x in triple1]

    This is because of the order of operations that you have

    >>> 25 // 255 * 100
0
>>> 25 * 100 // 255
9

    Note that as long as x is floating point or you use 100.0 or 255.0 then you will get a floating point result so that

    >>> 25.0 * 100 // 255
9.0

    while

    >>> int(25.0 * 100 / 255)
9

    Now you can say

    r, g, b = triple1pwm

    or

    r, g, b = [int(x*100/255) for x in triple1]