PWM and the Spinsemi FV-1

[aziltz]

Has anyone used PWM signals to drive the FV-1 pot inputs from a PIC or other microcontroller?  I'd like to hear the details

PWM + FV-1 or similar doesn't turn up any hits unfortunately.

[Digital Larry]

Haven't done it personally (yet).  Think it's a pretty valid approach.  Pot control inputs on FV-1 are supposedly 10 bit resolution, so for the best experience, have at least that in your PWM.

[aziltz]

thanks.  Anyone else? Beuller?

[slacker]

Like Larry, I haven't tried it but it should work. In theory the internal low pass filtering on the pot inputs should convert the PWM signal into the equivalent of a DC level. If it doesn't work all you would need is a simple RC lowpass filter between the PWM output and the FV-1.
I've got a PWM LFO I've been working on, if I get time I'll try hooking it up and see what happens.

[free electron]

I have done that many times, although i haven't tried to feed the POT inputs with a pure PWM signal. I always filter them with a simple RC lowpass right at the MCU pins (=less noisy layout or less potential problems with other signals picking up these fast pwm transients). Just make sure the range is 0-3.3V.

[peterv999]

The eTap2hw project is also, available with automation using PWM.


Piet

[aziltz]

The eTap2hw project is also, available with automation using PWM.


Piet

is the arduino program code available?

[GuitarPhil]

The eTap2hw project is also, available with automation using PWM.


Piet

is the arduino program code available?

It's on my blog 

https://echotapper.wordpress.com/

Click on the 'Latest Updates Here' on the menu bar but you'll probably want to read some of the stuff on the blog too 

We do use the PWM outputs to drive the Pot inputs but using a low-pass filter.

Phil.

[aziltz]

Found it!  Hopefully this will help me write a pot-to-pwm for PIC

[GuitarPhil]

Be careful if your running a 5V Arduino or the like as you'll need to have a voltage divider on the output of your PWM filters so it doesn't feed more than 3.3V into the FV-1 pot inputs.

Phil.

[peterv999]

Be careful if your running a 5V Arduino or the like as you'll need to have a voltage divider on the output of your PWM filters so it doesn't feed more than 3.3V into the FV-1 pot inputs.

Phil.

The I/O board used for the eTap2hw automation includes this voltage devider and snubber to compliment Phil's software. Also, this board is a shield that accepts the Adafruit LCD shield with buttons or my 38mm I2C to LCD board if height is the limited factor using the Adafruit LCD shield.

Piet
www.echotapper.nl