Posts made by LaurentN

Additional information.
If I put omega2-ctrl gpiomux set pwm0 pwm in a script.sh file and run it then I get the following message:
unknown group/function combination.
Does anybody has an idea how to resolve this issue?

Hi.
I want to setup a permanent gpiomux configuration on my omega2.
At the moment I have to enter at every boot the following command to setup my gpio configuration

omega2-ctrl gpiomux set pwm0 pwm

I tried to put this line into the '/etc/rc.local' file without success.

My question is how to configure this gpiomux settings in a way that after a reboot the configuration is available?

Thanks

Re: [WS281x](SK6812 driver for the Omega2? [Solved])

Hi.
In the last days I played a bit with Python to get the WS281x working wirth Luz' module.
As I want to use HLS color schema (it allows to change the luminosity of the color by only one number), I programmed a function HLS to RGB color string:

def hls2rgb(h,l,s):
	r, g, b = colorsys.hls_to_rgb(h,l,s)
	shr = str(hex(int(r * 255.0)))
	shg = str(hex(int(g * 255.0)))
	shb = str(hex(int(b * 255.0)))
	# print ([int(255.0*r), int(255.0*g), int(255.0*b)])
	if len(shr) == 3:
		shr = shr[0:2] + str(0) + shr[2]
	if len(shg) == 3:
		shg = shg[0:2] + str(0) + shg[2]
	if len(shb) == 3:
		shb = shb[0:2] + str(0) + shb[2]
	col_led_string = shr[2:4].decode('hex') +shg[2:4].decode('hex') + shb[2:4].decode('hex')

By using the following additional function, it allows using a 2 dimensional color matrix which is converted in the corresponding hex color string needed for the module. (It might be useful and easier to use a matrix to handle LED chains instead of a string of hexadigitals)

def hls2rgb_hexstring(hls_matrix):
	dim1 = len(hls_matrix)
	try:
		dim2t = len(hls_matrix[0])
	except:
		dim2t = 0
	if dim2t == 0:
		dim2 = dim1
		dim1 = 1
	else: 
		dim2 = dim2t
	
	if dim1 == 1:
		h = hls_matrix[0]/360.0
		l = hls_matrix[1]/100.0
		s = hls_matrix[2]/100.0
		col_led_string = hls2rgb(h,l,s)
		return col_led_string
	else:
		col_led_string=""
		for i in range(0,dim1):
			h = hls_matrix[i][0]/360.0
			l = hls_matrix[i][1]/100.0
			s = hls_matrix[i][2]/100.0
			col_led_string = col_led_string + hls2rgb(h,l,s)
		return col_led_string

To display a color gradient among several LED's (here 40) one has to run this code, which is using both function above:

color_start = 0
color_end = 359
nr_led = 40
lum = 2
sat = 100
colorMatrix = []
for i in range(color_start,color_end, abs(color_end-color_start)/nr_led):
	colorMatrix.append([i,lum,sat])
	#print [i,lum, sat]
print colorMatrix
with open('/dev/ledchain0','w') as export:
	export.write(hls2rgb_hexstring(colorMatrix))

Thanks Luz for this explanation.
I forgot that HSL values could be transformed into the RGB values.

I used python to control the 8 LED ring (WS2812b) using code like

with open('/dev/ledchain0','w') as export:
			export.write(col_string)

where 'col_string' is a a text string containing all the RGB values for the hole ring.
However sometimes (especially when I have to calculate the RGB values and then compose the string), I get an error 'ValueError: invalid \x escape'

Maybe this isn't the best way to control the LED with python and you can advise a better one.

Regards

Hi
I'm wondering if (and how) it is possible to dim the LED with the p44-ledchain module? (keyword: change of duty cycle)
Regards
Laurent

Hi.
I'm wondering on which boards the PWM function is available?
Mainly I'm interested if I can use PWM on the power board and mini dock.

Regards