PWM and DIR -> +/-10VDC analog signal

[visky]

I am interesting to build simple signal converter .
Signals to convert from parallel port PWM and DIR to +/-10VDC analog out signals .

How to do that?
Is it posible to make it with max547 DAC and which components to add?

Marko

[pminmo]

PWM's make a good DAC with just a low pass filter and vary the duty cycle. Lots of information if you do a google search on PWM and DAC. However since you want to convert it to a +/-10V output, and the parallel port is logic level, use a solid state analog switch to switch a +10V source or a -10V source based on the direction signal. Pick a switch that will handle the frequency of your pwm and that will switch +/- 10V.