I was hoping someone could assist me with a project. I have built a device which uses a potentiometer (analog) to control an audio filter (analog). I was looking to use the arduino dual ultrasonic sensor module (HC-SR04) to replace the potentiometer in this circuit to act almost like a proximity sensor; raising the filter cut off when a person gets close to the sensor. Do you know anyone who might be able to help in coding this? and also, what needs to be connected to what?? Thank you for any help you can provide. The potentiometer I would like to replace with the sensor is circled in red. I don't use the 'Fine Tune' potentiometer next to this, so please ignore.
closed as too broad by per1234, user31481, MatsK, jose can u c, gre_gor Nov 27 '17 at 20:31
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
The HCSR04 module is a digital proximity sensor, needing a microcontroller to read values from it. If you really want to use this then you will have to use a microcontroller as a digital to analog converter and map distance values from the HCSR04 to voltages.
However, a better solution would be to use some kind of analog distance sensor. I have used the Sharp IR distance sensors before (with Pololu carrier) and have had great success. This model also comes in a 3V flavor which might simplify your circuit design. You would now only need some analog circuitry to get the voltage values into the correct range.