Duplicate potentiometer with sonar
I am quite of a newbie in electronic but I learn quickly, here is my project:
I have a small amplifier wich is commended by a potentiometer. For some reason I would like to duplicate this potentiometer with a sonar (such as this). The potentiometer is a B50K (as this one apparently) so that if you turn it completly counterclockwise it switches the amplifier off. It's a logarithmic potentiometer I think.
-First, the idea is that I could use the sonar or the normal potentiometer equivalently (parallel assembly?)
-Secondly, I think I'd set a small switch (wich one?) that makes the sonar inactive so that the device is commanded with the normal potentiometer only.
-Finally, the way I would like the sonar to work is as follow: if you pass your hand just above it (at around 5cm) it acts as a switch (on/off), but if you putt your hand higher (from 20 to 60cm) you can adjust the volume by moving your hand verticaly.
The main question is what PLC (picaxe I guess) do I need? I'll upload a diagram of how I plan to make it soon, if anyone want to drop an eye on it... :)
Thank you in advance.