-->
Page 1 of 2

high ADC sample rate for FFT

PostPosted: Wed Jun 07, 2017 3:47 am
by whyphi
Hello,
can somebody tell me, if and how it is possible to get a constant "high" sample rate (>5 ksps) from the EPS8266 internal ADC?
I would like to implement a FFT using the internal ADC under the Arduino IDE.
Thanks

Re: high ADC sample rate for FFT

PostPosted: Wed Jun 07, 2017 6:51 am
by schufti
did you see any hint in the datasheets that such high conversion rate (let alone constant) is achievable at all?

Re: high ADC sample rate for FFT

PostPosted: Wed Jun 07, 2017 7:07 am
by whyphi
In the following post, a conversion time of 5us is given?
http://bbs.espressif.com/viewtopic.php?t=2440

Re: high ADC sample rate for FFT

PostPosted: Wed Jun 07, 2017 8:51 pm
by mrburnette
whyphi wrote:In the following post, a conversion time of 5us is given?
http://bbs.espressif.com/viewtopic.php?t=2440


... but, that response was for a native SDK application, not for an Arduino 'side loaded' program. The RF section and stack needs to be serviced every 50mS or quicker (normally done when loop() repeats.) So, your A/D and all overhead must complete in 50mS ... a long time, but you need to be aware of the limitations of nonOS which manages the Arduino pseudo-thread.

Ray