For data acquisition, it isn't too hard to write bit-bang code for a FTDI interface chip, which was already mentioned. This can be done using FTDI's drivers, takes about 3 pages of C code. I did this once on a rainy weekend with freeware MINGW and gcc. Let me know if you need a "hello world" example. For example, "signalyzer H4" puts one such chip into a neat little box, but you can get the same a lot cheaper on an unboxed board (and forget about the signalyzer example code, just go straight for the chipset documentation or send me a mail) This provides USB-to-GPIO. And / or serial interfaces to just about any standard using some internal state machine. The FTDI chip is a robust and future-proof interface to get data into (and out of) the PC. Then, it needs a converter, there seem to be quite many to choose from. Search "coolcomponents.co.uk" for "breakout board", maybe there is a cheap sensor that can be wired easily.
PC Data Acquisition
Started by ●March 13, 2013
Reply by ●March 14, 20132013-03-14
Reply by ●March 14, 20132013-03-14
Jan Panteltje wrote:> On a sunny day (Wed, 13 Mar 2013 18:11:17 -0500) it happened Jamie > <jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in > <GF60t.148683$wI7.5227@newsfe15.iad>: > > >> With today's PC's, it's common to get 192k sampling rates. > > > You can use a 4046 VCO, recod to a soundcard channel, > and then display later with a frequency counter :-) > In the sities I recorded slow san TV that tway, FM, on tape. >Yeah well, I wrote a slow scan TV program for windows :) Jamie
Reply by ●March 15, 20132013-03-15
On Wed, 13 Mar 2013 12:05:05 -0500, Vladimir Vassilevsky <nospam@nowhere.com> wrote:>On 3/13/2013 11:44 AM, Tim Wescott wrote: > >> I have a need to sample one channel of data at between 200 and 2000 >> samples per second, 12 bits or so, and store it away. > >For one time deal: take your favorite micro eval board from the shelf; >connect it to USB to RS232 dongle; put together simple application; >record file from terminal program on PC. All preparation should take >less then half an hour. > >Vladimir Vassilevsky >DSP and Mixed Signal Designs >www.abvolt.com >Seconded. ?-)
Reply by ●March 15, 20132013-03-15
On Wed, 13 Mar 2013 16:45:06 -0700 (PDT), George Herold <gherold@teachspin.com> wrote:>On Mar 13, 4:22�pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat> >wrote: >> On Wed, 13 Mar 2013 11:10:30 -0700, Rob Gaddi >> >> >> >> >> >> <rga...@technologyhighland.invalid> wrote: >> >On Wed, 13 Mar 2013 10:54:17 -0700 >> >Joerg <inva...@invalid.invalid> wrote: >> >> >> Tim Wescott wrote: >> >> > This is slightly OT for all the groups I'm posting to, but something many >> >> > of you should have done. >> >> >> > I have a need to sample one channel of data at between 200 and 2000 >> >> > samples per second, 12 bits or so, and store it away. >> >> >> > The signal happens to be on a 4-40mA line already, to make life easy for >> >> > getting off-the-shelf hardware. >> >> >> > I need to store hours of guaranteed-uninterrupted data, or failing that, >> >> > store data that's timestamped at the measuring device (not just in the PC >> >> > software) so that I can see what's missing and deal with it. �(dropouts >> >> > of even a half second or so would be OK, as long as the timestamps are >> >> > correct). >> >> >> > The mental model I'm carrying around is a laptop PC, connected to some >> >> > little box via USB, quietly buzzing away in a corner making multi- >> >> > megabyte files with the information I want. >> >> >> > I assume that this is a no-brainer with National Instruments hardware and >> >> > software -- am I correct? �If not, is there a solution that you can >> >> > recommend? �Do you have a favorite other than NI? >> >> >> I usually use this for such jobs: >> >> >>http://labjack.com/u3 >> >> >> Plus a few resistors. It also comes in a version for LAN connection in >> >> case that's more practical. >> >> >> It comes with a light version of Azeotech SCADA software which is really >> >> handy if you don't want to mess with computer programming or Excel-VBA >> >> too much. If you get stuck both Labjack and Azeotech have rather >> >> responsive forums where their respective support staff chimes in. And if >> >> someone screws up a PID you can become the expert and help them out :-) >> >> >> -- >> >> Regards, Joerg >> >> >>http://www.analogconsultants.com/ >> >> >Wow. �I was actually just wondering about something like this the other day. �And the fact that it comes complete with cross-platform drivers and Python bindings makes it pretty seriously nifty. >> >> Maybe 1% of the cost of a NI solution.- Hide quoted text - >> >> - Show quoted text - > >Hmm, Labjack as an answer to NI. We're always getting requests, to >make Labview, NI 'compatible' apparatus/ experiments. The price tag >scares me... and then labview changes every three years or so. > >George H.Well shucks, NI has to do something with all those support dollars. ?-(
Reply by ●March 15, 20132013-03-15
On Wed, 13 Mar 2013 20:13:53 -0400, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Wed, 13 Mar 2013 16:45:06 -0700 (PDT), the renowned George Herold ><gherold@teachspin.com> wrote: > >> >>Hmm, Labjack as an answer to NI. We're always getting requests, to >>make Labview, NI 'compatible' apparatus/ experiments. The price tag >>scares me... and then labview changes every three years or so. >> >>George H. > >I'm afraid it's going to be necessary to be a serious player, it's >becoming a standard. > > >Best regards, >Spehro PefhanyDo you mean glitzy substandard? ?-)
Reply by ●March 16, 20132013-03-16
On Fri, 15 Mar 2013 02:03:34 -0700, josephkk <joseph_barrett@sbcglobal.net> wrote:>On Wed, 13 Mar 2013 16:45:06 -0700 (PDT), George Herold ><gherold@teachspin.com> wrote: > >>On Mar 13, 4:22�pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat> >>wrote: >>> On Wed, 13 Mar 2013 11:10:30 -0700, Rob Gaddi >>> >>><snip>>>George H. > >Well shucks, NI has to do something with all those support dollars. > >?-(Well I develop software for both NI and Data Translation hardware. Getting in with NI is really not that expensive, I just don't use LabView. I have actually never had a support issue which their engineers were not able to resolve, and it saves me a huge amount of money over doing it inhouse. Data Translation's guys are great too and they make some fantastic hardware, much cheaper than the NI alternatives. Mark DeArman
