- From: Bernd Porr <BerndPorr_at_f2s.com>
- Date: Thu, 03 Mar 2005 09:36:42 +0000
You can use the program
http://www.linux-usb-daq.co.uk/software2/comedi-record/
to sample quite slowly. It internally always samples at 1kHz and then
averages on the fly to get a lower rate. It also has a 50Hz notch filter
(sorry, American colleagues). However, the filter frequency can be
changed in the program. I used it also with thermocouple sensors.
/Bernd
www: http://www.berndporr.me.uk/
http://www.linux-usb-daq.co.uk/
Mobile: +44 (0)7840 340069
Work: +44 (0)141 330 5237
University of Glasgow
Department of Electronics & Electrical Engineering
Room 519, Rankine Building, Oakfield Avenue,
Glasgow, G12 8LT
Daniel Nilsson wrote:
> Hi All,
>
> I'm working on a project where I'm trying to sample more really slow
> varying inputs, I'm only interested in getting a new value every 500ms
> or so and the data will not vary much in this time period.
>
> From looking at the Comedi API I find function designed to help out
> sampling such data, though they all have the status deprecated. Why
> are the functions deprecated ? Is there something else that provides
> the same functionality ?
>
> If not, does anyone have any filter code that you can share the is
> designed to filter out any noise that might be present on the inputs ?
> The issues that I'm having right now is that the inputs don't vary
> much but I'm getting a measurement values that move back and forth
> around the actual value. I assume some of this is digital noise and
> some is analog noise (60Hz noise from the mains for example). I would
> think someone had already written some code to filter out such noise ?
>
> Any other suggestions would be welcome. I'm trying to measure the
> voltage and current of a Ni-Cd battery that is being discharged
> through a resistor if anyone was curious...
>
> Thanks
Received on 2005-03-03Z09:36:42