PWM on digital out

[Egeus]

Hi,
is it possibly to control one of the digital out pins with (software) pwm? I need to adjust the brightness on a LED. It should have a frequency greater then 100Hz (about 1000Hz would be really nice). I control the RP with the serial interface.
Thanks,
Chris

[jmontse]

I have found that with the new version of Scope+generator, the generator allows additional output signal modes, and one of them is PWM.
Another matter is if there is a new console command that brings PWM out easily....
The latest 0.94 OS documentation seems that still is being written.

[Egeus]

The generator console command only allow to control the FPGA-outputs. I want to use a boring digital pin (of the extension connector E1). The use of the fpga outputs is a little bit oversized, becaus I just want to control the brightness of a led.
Thank you,
Chris

[Nils Roos]

The monitor command line tool does probably not execute fast enough to use it for bash-pwm. Either you dedicate one of the auxiliary analog outputs to your led and configure it via monitor or you write a program that toggles a gpio pin yourself.

[Egeus]

I think you are right, the monitor tool is not fast enough. The timing is terrible...

I tried a Bash-Script like this:

while true
do
monitor 0x40000010 0x02 #Turn led on
usleep $timeOn #Wait
monitor 0x40000010 0x00 #Turn another led on and first off
usleep $timeOff #Wait
done

The timing was set so that it was 990µs off and 10µs on but it makes no difference when I set it so 10µs off and 990µs on...
Or had I done a misstake? Any other ideas? A control with the analog outputs is not possible (Voltage is not high enough).