Picaxe 08m2+ and RGB led

[rudster]

Hey,
My project is to get 4 RGB leds to go throuhg the rainbow spectrum useing a picaxe 08m2+ and two SN74HCT244 octal buffers. I attached a schematic but my main problem is the code.
I'm having trouble writing it up and when I do practice runs the LEDs flicker while fading during dim.
heres what I have so far not much wondering if anything can help. Thanks!

#picaxe 08m2

symbol	REDLED = 2
symbol	GRNLED = 1
symbol	BLULED = 4


symbol	SPEED = 10

low BLULED
low REDLED
cycle:

	b0 = GRNLED : call fadeup 
	b0 = GRNLED : call fadedown
	return

fadedown:
	for b1 = 0 to 255
		pwm b0, b1, SPEED
	next
	high b0
	
	return
	
fadeup:
	for b1 = 255 to 0 step -1
		pwm b0, b1, SPEED
	next
	low b0
	
	return

**broken link removed**

 

[be80be]

You need to set the color on and use PWM on the ground if you want it to fade with out flicker.

 

[rudster]

You need to set the color on and use PWM on the ground if you want it to fade with out flicker.

hmmm but the rgb led has a common cathode how would I control each color?
I'm sorry I'm just really bad with coding

 

[ronsimpson]

You have 3 outputs R,G,B. If you only use 0 or 1 you will only get 8 colors. Black......White.

If you PWM the outputs you can get 1000s of colors with only three outputs.
With in 1/100 of a second, you can have G=on, R=on for 2/1000 of a second and B=on for 6/1000 of a second.

 

[be80be]

I would set the colors bit bang pwm and fade with the ground using hardware pwm

 

[rudster]

Thanks for your help guys, I found some sample codes online and trying to play with it, this is working alright but still some flickering.
If you can show some pseudocode or explain a little more on how to use the ground as pwm that'll be great
Sorry for the trouble, I just cant seem to get it
Thanks again!

#picaxe 08m2

symbol	REDLED = 2
symbol	GRNLED = 1
symbol	BLULED = 4


symbol	SPEED = 10
symbol	REDLEVEL = w3
symbol	REDDIR = b2


main:

	setfreq m8

	do

	

	
		
		
		; begin colour fading
		REDLEVEL = 800
		REDDIR = 0
		pwmout REDLED, 200, REDLEVEL
				
		do while REDLEVEL > 0

			call cycle
	
		loop
		
		pwmout REDLED, off
	
	loop
	
cycle:

	b0 = GRNLED : call fadeup 
	b0 = BLULED : call fadeup 
	b0 = GRNLED : call fadedown
	b0 = BLULED : call fadedown
	b0 = REDLED : call fadedown
	return

fadedown:
	for b1 = 0 to 255
		pwm b0, b1, SPEED
	next
	high b0
	Call fadered
	return
	
fadeup:
	for b1 = 255 to 0 step -1
		pwm b0, b1, SPEED
	next
	low b0
	Call fadered
	return

fadered:
	if REDDIR = 1 Then
		if REDLEVEL = 800 then
			REDDIR = 0
		else
			REDLEVEL = REDLEVEL + 25
		endif
	else
		if REDLEVEL = 0 then
			REDDIR = 1
		else
			REDLEVEL = REDLEVEL - 25
		endif
	endif
	pwmduty REDLED, REDLEVEL
	return
	
end