As part of a larger project, I would like to be able to control a set of 8-10 PWM signals remotely, from a smartphone at a distance of 10 meters or more. I will probably convert the PWM signals to analog voltages, and reduce their voltage swings to more like 0-1v, using a resistor divider and RC filter; they will drive high impedance loads in the remainder of the project. I’d write an app for the smartphone allowing user control over the duty-cycle of each PWM signal (and thus the analog signal levels).
It seems to me that the way to go is Arduino, interfaced to the phone with Bluetooth. I'd need one of the higher end Arduinos to get enough PWM signals (the basic ones like Uno only have 6 PWM outputs). Software-generated PWMs are probably not high-frequency enough, as I’d like the filtered analog signals to be as ripple-free as possible. There seem to be several ways to interface Bluetooth to Arduino, such as the HC-05.
If people here concur with this approach, I shall move this question to the Arduino forum.