Comments on: 4 Channel PWM output with PIC16F690

By: psichron

psichron — Thu, 16 Apr 2009 19:36:14 +0000

No, not with the 16F690′s PWM generator. You’ll have to use your own timing functions and switch the pins on/off manually.

By: Ryan

Ryan — Thu, 16 Apr 2009 16:25:08 +0000

Unfortunately i dont have the datasheet but its the standard common annode 4 pin rgb led. Basically i want to manually control the colour output from the led with 3 pots.

Many thanks

By: Ryan

Ryan — Thu, 16 Apr 2009 16:12:44 +0000

Is it possible to have different signals coming out of the 3 pwm pins? i.e pin5 – 100Hz, pin6 – 200Hz & pin7 – 500Hz or something like this?
Is this how the led colour changes or am i wrong?

Many thanks

By: psichron

psichron — Thu, 16 Apr 2009 13:50:55 +0000

Do you have a link to the datasheet of the LED?
Because STRA, STB, etc is how you enable/disable output of the channels, so you have the same signal coming out of all the enabled channel pins.

By: Ryan

Ryan — Thu, 16 Apr 2009 13:47:38 +0000

Hi
I have tried this but it only dims or brightens the led, doesnt actually change the colour? The colour stays red??

Thanks

By: psichron

psichron — Thu, 16 Apr 2009 13:41:03 +0000

”
Use registers STRA, STRB, STRC, STRD to turn on/off each of the 4 channels
STRA = pin5
STRB = pin6
STRC = pin7
STRD = pin14
”

So you can turn on/off the channel output on pin5 by setting STRA = 1 (on) or STRA=0 (off).

By: Ryan

Ryan — Wed, 15 Apr 2009 16:20:32 +0000

Hi
How do you select and output individual pwm channels? i have 3 pots and i want to use them to control the colours the rgb led will output. I am quite stuck. If you could help it would be much appreciated.

Many thanks