Arduino PWM~ to CV for analogue Synth (Using Max Msp)

Projects General Guidance
1

Hello,

I want to be able to send CVs from Max to an analogue synth. The PWM~ outputs are 0-5 Volts? Which would seem to fit the analogue synth CV range. I will be scaling the data in max (either from 0-127 or -1 to 1) and I will be using Maxuino or some such ready made interface. My question really is - is it any more complicated than that? Are there existing circuits for this? Is it kind of the same circuit that dims an LED but with a patch cable soldered to the output

Thanks for any help

Will

2

A [u]low-pass filter[/u] can be used to "average-out" the PWM and convert it to analog. Depending on the impedance of the circuit you are driving, you may need an op-amp buffer (or you could use an active filter).

The PWM~ outputs are 0-5 Volts?

PWM is digital, so the outputs are 0 OR 5V, with an average somewhere between 0 and 5V. i.e. If you write a PWM value of 50% (127 or 128), the output will be high half the time (5V) and low half the time (0V) for an average of 2.5V.

I will be scaling the data in max (either from 0-127 or -1 to 1)

What?

3

What?

0-127 is the standard midi range and -1 to 1 is the standard MSP range in Max