Replace Pot with Analog Output??

I'm currently taking apart an old radio and was hoping to be able to control the volume with my arduino.
The volume knob on the radio's circuit board appears to be connected to a 10K pot.
Does anyone know how I would go about controlling the volume of the radio with an arduino, possibly with analogWrite??
Thanks!!! :smiley:

10k Log Taper Digital Pot to replace the radio's volume control, your choice of SPI or I2C interface, the Arduino will do either. Dallas Semiconductor or Maxim produce these.

Otherwise you could go Rube Goldberg and have a servo turn the volume control..

Does the pot directly control the volume or does it control the amp? it's worth checking the range of voltages on seen on the wiper of the pot. I have a similar problem at the moment:

@daveg, good point.


The way most radios work (think block diagrams), you have an antenna that feeds into a dual conversion super heterodyne RF stage that dumps its output into a detector to extract the audio. The detected audio is then fed into a audio voltage amplification stage whose load is a potentiometer (resistor portion). The wiper on the potentiometer then feeds into the audio power amplifier that drives the speakers.

You will need to check the voltage across the potentiometer resistive element and make sure it doesn't exceed the specs on the digital pot. Audio = ac and with a full signal should be something like 1 volt AC. Your results may vary depending on circuit design.