Arduino Forum

Topics => Science and Measurement => Topic started by: ranos on Sep 10, 2012, 02:26 pm

Title: analog outputs
Post by: ranos on Sep 10, 2012, 02:26 pm
Hello,

I'm looking to produce a wave form with the arduino.
DC + AC with variable frequency, 0-10V - real analog and not PWM.

is there any arduino that enables this feature without addtional HW?
Title: Re: analog outputs
Post by: AWOL on Sep 10, 2012, 03:06 pm
No.

But the additional hardware can be really simple.

(You didn't mention frequency. Very important.)
Title: Re: analog outputs
Post by: nahoona on Sep 12, 2012, 10:44 am
without HW, the answer ,as far as I know, is NO.

but for DC, you can use simple LPF (i.e., RC) to generate DC from PWM.
for AC, you can also play around LPF and PWM; however, I guess, freq. will be limited > several KHz (If you are not using 490Hz default PWM), also the  wave form look rather saw tooth...

A clever summing network might be needed to add two signals.

Nahoona
Title: Re: analog outputs
Post by: MarkT on Sep 13, 2012, 02:19 pm
Really need to know frequency requirements, signal/noise ratio desired, resolution of output, waveforms desired, accuracy requirement, drive requirements (output impedance)...   Extra hardware is necessary, at least an external DAC and opamp amplification to 10V.  Not that simple, but certainly doable for low frequencies (audio range?).
Title: Re: analog outputs
Post by: jgmdavies on Dec 12, 2012, 10:15 am
The recently-released Arduino Due has DACs / analog output.  You'd probably need some external level shifting / amplification as well, e.g. one op-amp.

Jim