Don't forget to measure half-wave rectified signals to see what results you get (square, sine and triangular) as that is something that many RMS meters fail on.
/Martin On 6 Juni, 00:04, Cobra007 <mic...@xiac.com> wrote: > That is a fabulous result! > > I think I would do the same thing, take the 1000 readings non- > interrupt based. See how accurate it is, otherwise take 2000 samples, > or 3000 which will only take 0.5 seconds. > > Let us know the result, measure sine waves, triangular waves and > square waves. > > Michel > > On Jun 5, 11:42 pm, Tobias <tobiasmu...@gmail.com> wrote: > > > > > David: I am using the INA219 averaging at 128 samples. It is a very > > good feature indeed. We are trying to get a library together with all > > the functions so we can switch back and forth between some of the > > features depending on what is being read from it. > > > Michel: Tests are done! I found a faster way to do the i2c. And your > > math worked great reducing processing time! > > I tried to run the encoder function once in a while but it did not > > work. Lets say was a mistake not to put a interruption pin on my IO > > header. > > > Just i2c get bus voltage: 193 ms > > Using sq() function: 388 ms > > Using z*=z then summing: 196 ms > > Including encoder z*=z: 207 ms > > > At 207 ms for a thousand readings we have 4.8 kHz, or 80 points for a > > 60Hz sine. =) > > I think I will finish up the code and try to take some measurements. > > > You say doing time interrupt is going to slow this down. What about > > counting all the 1000 readings and dividing by the time it took to > > make them? Not a good idea? > > > Tobias > > > On 5 jun, 04:14, Cobra007 <mic...@xiac.com> wrote: > > > > > The way to do this properly, as in how a real DMM does it, is to use a > > > > dual-slope converter that will produce a useful number with every > > > > sample. > > > > > These successive approximation converters that are common as dirt these > > > > days are just not very good at the job of converting a signal and > > > > producing a useful number. > > > > > -- > > > > David Forbes, Tucson AZ > > > > DMMs with true RMS measurements have been discussed here before, but > > > the only proper way to measure true RMS is by following it's > > > definition. > > > > My DMM is also true RMS, but really, any DC voltage shows as 0V RMS > > > which is by definition incorrect. Leaving out the DC component means > > > including a high pass filter, but they are not ideal, so for any > > > frequency below the specified frequencies, you cannot rely on the RMS > > > reading. Following this integral and squaring method should produce a > > > reliable reading from 0Hz up to a certain frequency. > > > > Michel -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixie-l@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
