dentex wrote:Thanks for the input, but I was thinking about a high power LED installation and those drivers seems to be proper, from what I read around. They need an external power supply, i.e. 12V or 24V, and will take care of driving the right number of high power LEDs with constant current (depending on the version: 300mA, 350mA, 500mA, 600mA, 700mA, 1000mA). Sorry if this was not clear in the 1st post.
My doubt regards the voltage available from the gpio pins when they are HIGH during each PWM cycle. According to the image from the datasheet linked above, should be OK.
But just as a confirmation...
Those devices seems to be really of common use, but I didn't found anything on this forum (apart another single thread, saying nothing on PWM).
There isn't much to say about PWM.
There are several gpios which provide specialised PWM. Up to two of those may be used at once. Gpios 12/13 or gpios 18/19 on the A+/B+. Just gpio 18 on the A/B.
All the user gpios can be used for hardware timed PWM or software timed PWM. Hardware timed PWM is good enough for servo positioning, LEDs brightness control, and DC motor speed control. I'd only use software timed PWM for DC motor speed control.