PIC scope test1
in [Design]
|
From: Jan Panteltje on 16 Mar 2010 19:46 On a sunny day (Tue, 16 Mar 2010 22:36:38 +0100) it happened Fred Bartoli <myname_with_a_dot_inbetween(a)free.fr> wrote in <hnoti5$pg$1(a)speranza.aioe.org>: >Jan Panteltje a �crit : >> PIC scope test1 >> >> This is the maximum aquisition speed I can get out of a PIC 18F14K22, >> 10 kHz sinewave: >> ftp://panteltje.com/pub/PIC_18F14K22_scope_10kHz_img_1876.jpg >> >> Not bad at all, if you realise it is 127 dots for about 5 periods. >> With 100 uS per period the display width is about 500 uS, >> that makes 500 uS / 127 = 3.9, say 4 uS per sample, or 250 kHz from the ADC. >> >> Trigger is rock solid too :-) >> Input is line level audio. >> >> > >You don't need a PIC to do that. That is, unless you want to impress >customers... > >All that's needed is a gold leaf electroscope, a protractor, a switch >and a stopwatch, or if you want to get fancy a synchronized rotary switch. Sure, do you watch TV with a Nipkov disk too? LOL :-) > >-- >Thanks, >Fred. >
From: Fred Bartoli on 17 Mar 2010 12:19 Jan Panteltje a �crit : > On a sunny day (Tue, 16 Mar 2010 22:36:38 +0100) it happened Fred Bartoli > <myname_with_a_dot_inbetween(a)free.fr> wrote in > <hnoti5$pg$1(a)speranza.aioe.org>: > >> Jan Panteltje a �crit : >>> PIC scope test1 >>> >>> This is the maximum aquisition speed I can get out of a PIC 18F14K22, >>> 10 kHz sinewave: >>> ftp://panteltje.com/pub/PIC_18F14K22_scope_10kHz_img_1876.jpg >>> >>> Not bad at all, if you realise it is 127 dots for about 5 periods. >>> With 100 uS per period the display width is about 500 uS, >>> that makes 500 uS / 127 = 3.9, say 4 uS per sample, or 250 kHz from the ADC. >>> >>> Trigger is rock solid too :-) >>> Input is line level audio. >>> >>> >> You don't need a PIC to do that. That is, unless you want to impress >> customers... >> >> All that's needed is a gold leaf electroscope, a protractor, a switch >> and a stopwatch, or if you want to get fancy a synchronized rotary switch. > > Sure, do you watch TV with a Nipkov disk too? > LOL > :-) > For what I watch it, I sure could do... -- Thanks, Fred.
From: JosephKK on 18 Mar 2010 00:06
On Tue, 16 Mar 2010 16:58:00 GMT, Jan Panteltje <pNaonStpealmtje(a)yahoo.com> wrote: >On a sunny day (Tue, 16 Mar 2010 07:07:19 -0700) it happened John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in ><724vp5th3fmmpu75u42duilnlf525q6ivl(a)4ax.com>: > >>On Mon, 15 Mar 2010 16:48:31 GMT, Jan Panteltje >><pNaonStpealmtje(a)yahoo.com> wrote: >> >>>PIC scope test1 >>> >>>This is the maximum aquisition speed I can get out of a PIC 18F14K22, >>>10 kHz sinewave: >>> ftp://panteltje.com/pub/PIC_18F14K22_scope_10kHz_img_1876.jpg >>> >>>Not bad at all, if you realise it is 127 dots for about 5 periods. >>>With 100 uS per period the display width is about 500 uS, >>>that makes 500 uS / 127 = 3.9, say 4 uS per sample, or 250 kHz from the ADC. >>> >>>Trigger is rock solid too :-) >>>Input is line level audio. >>> >> >>Cool. The first PC scope I did was an IBM 1401 with the waveform >>plotted on a line printer. Home-made ADC. >> >>John > >Yes, I did fft display on a printer..... >Like this: >********** 1000 >******** 1010 >*********** 1020 >*** 1030 >... > >I only made a home made ADC for video in 1979, >it was a board full of TTL and 74121 one shots. >6 bits, but it worked, nice picture. >Then somebody walked in and dropped a datasheet for a chip >on my desk that did the same thing, but then 8 bits, a 'flash' converter. >Too many comparators needed :-) > Sounds about the time the CDP3308(?) came out. |