In theory, this should not be difficult.
Use the pot as voltage divider with stable voltage reference and suitable filter on the output (say 47K and .22 uF). The pot's output would feed into a microcontroller with an ADC. You might want to apply a digital filter of some kind to this input as well. The micro then calculates the appropriate value to write to the pots to give the desired attenuation. Same value to all pots. I'd use a PIC because they are easy to use and many include the ADC plus I2C and SPI peripherals needed to communicate with the digital pots.
Use the pot as voltage divider with stable voltage reference and suitable filter on the output (say 47K and .22 uF). The pot's output would feed into a microcontroller with an ADC. You might want to apply a digital filter of some kind to this input as well. The micro then calculates the appropriate value to write to the pots to give the desired attenuation. Same value to all pots. I'd use a PIC because they are easy to use and many include the ADC plus I2C and SPI peripherals needed to communicate with the digital pots.
Doesn't use a pot as the control, but eliminates the microcontroller:
http://www.maxim-ic.com/appnotes.cfm/appnote_number/606/ln/en
If you're really set on the analog pot as a control you'll need some sort of A/D converter plus some glue logic to convert the ADC output into the proper format for the digital pot. Unless you get really lucky and find an ADC with a serial output that is exactly the right format for the digital pot input...
http://www.maxim-ic.com/appnotes.cfm/appnote_number/606/ln/en
If you're really set on the analog pot as a control you'll need some sort of A/D converter plus some glue logic to convert the ADC output into the proper format for the digital pot. Unless you get really lucky and find an ADC with a serial output that is exactly the right format for the digital pot input...
http://www.elecdesign.com/Articles/Index.cfm?ArticleID=2531#
Check this one out, I've built it and it works! but I went back to the microcontroller to be able to use the better chips. (i.e. PGA2310)
Sébastien
Check this one out, I've built it and it works! but I went back to the microcontroller to be able to use the better chips. (i.e. PGA2310)
Sébastien
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