Hi Rob, Thanks for the feedback, I'll give a try. I'm a beginner in JAL, so your code will be very interesting for me to learn. I built a freq. meter based on the PIC16F84A long ago, display was 7seg. Not sure if I keep any of the project files in some place. Just up to 1 Mhz, 6 digits. In PIC assembly, (almost forgot now). Kind regards, Jes.
On Sat, Sep 5, 2020 at 12:32 PM Rob CJ <[email protected]> wrote: > Hi Jes, > > Interesting project. > > Attached you find a first prototype which does do something. I tested it > with a frequency range of 2500 - 25000 Hz but it is not - yet - accurate. > > A frequency of 8000 Hz is displayed as 8237 Hz on the dispaly but at least > it is something to get you going. > > This version uses indeed the OLED display so if you want to compile this > program make sure you use the latest bee package since there you find the > driver for the SSD1306. > > I wil continue with making it more accurate and 'auto-ranging' to measure > lower frequencies. > > Kind regards, > > Rob > > ------------------------------ > *Van:* [email protected] <[email protected]> namens Jes < > [email protected]> > *Verzonden:* zaterdag 5 september 2020 12:08 > *Aan:* [email protected] <[email protected]> > *Onderwerp:* Re: [jallib] Some help needed to measure pulse length > > Thanks Rob. I'm not in a hurry, just learning and trying to get profit > from what I learn. > My project is a simple shutter speed meter for old film cameras (which I > collect and repair). > There is a little led laser pointing to a phototransistor sitting on the > film plane and going through the lens socket. Max shutter "speeds" (the > term is used in photography) are of 1/8000 of sec. On the other end, time > can be a long exposure of minutes or even hours, but normally measuring up > to 5 sec should be enough to certify the accuracy of the shutter. Most > pictures are taken in a range between 1/30 sec and 1/500 sec. Many old > cameras have a restricted range, not beyond 1/250 sec. > I would like to have an autonomous unit (not tied to a, computer) so I > would need only a few pins, just one for the signal and two for an small > I2C display, like the ones powered by the SSD1306 :O) > I was following the thread because that. > Now I have to find out if one of the small 12F units is able to do that. > Would be a perfect fit for my needs. > Kind regards. > Jes. > > El sáb., 5 sept. 2020 10:17, Rob CJ <[email protected]> escribió: > > Hi Jes, > > Since my previous project was finished I was thinking of prototyping this > frequency counter in JAL. My idea is to use it in combination with an > SSD1306 display and test it using the library I created for the Si5351 > although the range will be limited of this frequency counter. > > I think of making it 'auto ranging' as to increase the frequency range > indeed by changing prescaler values as you mentioned to measure lower > frequencies. I do not yet know how low it can measure. > > I might even post it on Instructables as prototype. I saw some examples > there based on Arduino but most of them are very simple, that is no > auto-ranging and so limited in the range it can handle. > > I started today, not sure how long it wil take but when it is done I will > post the source file on Jallib or on Instructables. > > BTW I will base it on a PIC16F1823 since that is the one I often use in my > projects but you can use other PICs as long as it has the capture function. > As said I do not know how long it will take so don't wait for it 🙂. > > Kind regards, > > Rob > > ------------------------------ > *Van:* [email protected] <[email protected]> namens Jesito's > μFabLab <[email protected]> > *Verzonden:* zaterdag 5 september 2020 09:55 > *Aan:* jallib <[email protected]> > *Onderwerp:* Re: [jallib] Some help needed to measure pulse length > > Many thanks Rob. I have to figure out how to do it. Is the timer working > at the MCU clock speed?. If so the 16 bit value might be too small to hold > the pulse length for i.e. a 5 sec pulse, isn't it?. I suppose some > prescaling should be done there... Have to investigate and read more on > that. > Kind regards. > Jes. > > > El jueves, 3 de septiembre de 2020 a las 18:51:51 UTC+2, > [email protected] escribió: > > Hi Jes, > > I just checked but I was mistaken, there is a procedure that calculates a > value for the timer based on a frequency. > > If you want to measure the length of a pulse you can use the capture mode > of a timer which is available in many PICs, for example the 16F1823.From > the datasheet: > Capture mode makes use of the 16-bit Timer1 > resource. When an event occurs on the CCP1 pin, the > 16-bit CCPR1H:CCPR1L register pair captures and > stores the 16-bit value of the TMR1H:TMR1L register > pair, respectively. An event is defined as one of the > following and is configured by the CCP1M<3:0> bits of > the CCP1CON register: > • Every falling edge > • Every rising edge > • Every 4th rising edge > • Every 16th rising edge > When a capture is made, the Interrupt Request Flag bit > CCP1IF of the PIR1 register is set. The interrupt flag > must be cleared in software. If another capture occurs > before the value in the CCPR1H, CCPR1L register pair > is read, the old captured value is overwritten by the new > captured value. > > Kind regards, > > Rob > > ------------------------------ > *Van:* [email protected] <[email protected]> namens Jes < > [email protected]> > *Verzonden:* donderdag 3 september 2020 13:45 > *Aan:* [email protected] <[email protected]> > *Onderwerp:* Re: [jallib] Some help needed to measure pulse length > > Thanks Rob, I look for it, just what I needed to know :0) > > El jue., 3 sept. 2020 12:01, Rob CJ <[email protected]> escribió: > > Hi Jes, > I thought there is already a Jal library to measure the width of a pulse > created by Matt. Would that do the job? > > Met vriendelijke groet, > Rob Jansen > ------------------------------ > *From:* [email protected] <[email protected]> on behalf of > Jesito's μFabLab <[email protected]> > *Sent:* Thursday, September 3, 2020 10:49:48 AM > *To:* jallib <[email protected]> > *Subject:* [jallib] Some help needed to measure pulse length > > Hello, > I'm new to JAL and I would like to measure the length of some pulses that > can be as long as 5 sec and as short as 1/8000 of second. > I have a handful of different pics, but ideally I would like to use a > small one, I just need one pin for the pulse, two more to interface to an > I2C small display and one more to reset and restart the measure. > Could anyone point me to an example that could guide me through this?. > I love the cleanless and simplicity of JAL. > Thanks in advance. > Jes. > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/29ca65ab-4f67-4e77-a321-9162fd396026n%40googlegroups.com > <https://groups.google.com/d/msgid/jallib/29ca65ab-4f67-4e77-a321-9162fd396026n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/AM0PR07MB62419C76A4D0F51F787AE7F5E62C0%40AM0PR07MB6241.eurprd07.prod.outlook.com > <https://groups.google.com/d/msgid/jallib/AM0PR07MB62419C76A4D0F51F787AE7F5E62C0%40AM0PR07MB6241.eurprd07.prod.outlook.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/CAJSrQ%3Df1Lm6tHoKCfC4LW68OcQgsKw5FUeGQgaKaiag5oKV8EA%40mail.gmail.com > <https://groups.google.com/d/msgid/jallib/CAJSrQ%3Df1Lm6tHoKCfC4LW68OcQgsKw5FUeGQgaKaiag5oKV8EA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/a079e103-5ea2-463a-b57d-53ad94caa730n%40googlegroups.com > <https://groups.google.com/d/msgid/jallib/a079e103-5ea2-463a-b57d-53ad94caa730n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/AM0PR07MB624194D03E0DB682805B8BF3E62A0%40AM0PR07MB6241.eurprd07.prod.outlook.com > <https://groups.google.com/d/msgid/jallib/AM0PR07MB624194D03E0DB682805B8BF3E62A0%40AM0PR07MB6241.eurprd07.prod.outlook.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/CAJSrQ%3Df4shHgZ9P7ykPjWW2JVG%2BaFdsFV9QLp6QMCdQ16hP1Vw%40mail.gmail.com > <https://groups.google.com/d/msgid/jallib/CAJSrQ%3Df4shHgZ9P7ykPjWW2JVG%2BaFdsFV9QLp6QMCdQ16hP1Vw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "jallib" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/jallib/AM0PR07MB624192315940757F3EB81813E62A0%40AM0PR07MB6241.eurprd07.prod.outlook.com > <https://groups.google.com/d/msgid/jallib/AM0PR07MB624192315940757F3EB81813E62A0%40AM0PR07MB6241.eurprd07.prod.outlook.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "jallib" group. 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