Hello highly honored public,
I did some research in low/high pass filter science and found a lot of calculation programs. In the contribution of Kiste 20 Mar. 2022 13:22:10 an R value of 680 .. 1 K is indicated and a C value of 1uF. The system works with 5 and 8 kHz. When I run the found calculation tool on it, I get very different values. I must be completely wrong again, but the transmitter and receiver do work, only with glitches. My question is outside the JALLIB world but I'll try anyway. regards Hans Op maandag 14 november 2022 om 21:19:26 UTC+1 schreef hans: > Hi Kiste, > > Sometimes I have to push things aside. So is this topic. I have taken up > the matter again and on my pin board both the transmitter and the receiver > work with a 12F683 at 1200 baud. I did put a 100nF in series at the output > according to your diagram. I also put a similar filter in the input of the > receiver. Identical to your proposal but because I know absolutely nothing > about filter matters I don't know if I did this right. > > I feed a separate uart signal as input and read out another uart with the > receiver. > > I recorded the signal with audicity and saved it as WAV. When playing back > to the receiver I do get responses but there is quite a bit of junk. > > My question : what should the inlet filter to the receiver look like. > > I know your box of thanks is already full, but I'll add another one. > > regards > > Hans > > Op zondag 19 juni 2022 om 12:46:36 UTC+2 schreef hans: > >> Hello all, >> I've tried many things, but I always had problems. I have now received a >> handful of MT8880 from china and this time they all worked. Even when I >> apply this I regularly have malfunctions, but if I repeat every command 3 >> times and check then it works. I'm a bit further, only the person I was >> working for has unfortunately chosen something else. So this will go in the >> "you can't know box" for now. >> We continue happily, it remains fun. >> regards >> Hans >> >> Op dinsdag 5 april 2022 om 19:57:25 UTC+2 schreef rob...@hotmail.com: >> >>> Hi Kiste, >>> >>> Nice solution. Hans has options to select from 🙂. >>> >>> BTW. @hans. I made as small error in my hardware receiver solution. >>> Capacitor C3 should be 2nF (two 1nF in parallel) but if I where you I would >>> try Kiste's solution first. If that works you are done. >>> >>> Kind regards, >>> >>> Rob >>> >>> ------------------------------ >>> *Van:* 'Oliver Seitz' via jallib <jal...@googlegroups.com> >>> *Verzonden:* dinsdag 5 april 2022 19:12 >>> >>> *Aan:* jal...@googlegroups.com <jal...@googlegroups.com> >>> *Onderwerp:* Re: [jallib] PWM serial audio transmission >>> I have only made small changes in the code and improved the comments. I >>> did not try this version, but I'm quite sure it should work. You only need >>> a PIC, a resistor, a TTL-Serial converter with a computer and the sample >>> audio file which i posted earlier to see it working. >>> >>> (You can even omit the resistor, but you could fry the PIC then. >>> Especially if you don't use the error LED and have no idea about what >>> volume to set) >>> >>> Greets, >>> Kiste >>> >>> Am Dienstag, 5. April 2022, 12:05:59 MESZ hat hans < >>> hansvanve...@gmail.com> Folgendes geschrieben: >>> >>> >>> Hello Rob and Kiste, >>> The next days i have a friend who can assist me. So (beside his AC >>> project) we might find time to continue with this . So please give us the >>> last info. >>> Thanks again >>> hans >>> >>> Op zondag 3 april 2022 om 15:57:03 UTC+2 schreef rob...@hotmail.com: >>> >>> Hi Hans, >>> >>> I also tried it with a lower frequency, 3330 Hz for the low tone and >>> 4030 Hz for the high tone so that the signal is strong enough when you >>> record it. >>> >>> If you want to know more, let me know. >>> >>> Kind regards, >>> >>> Rob >>> >>> ------------------------------ >>> *Van:* jal...@googlegroups.com <jal...@googlegroups.com> namens hans < >>> hansvanve...@gmail.com> >>> *Verzonden:* zondag 3 april 2022 15:11 >>> *Aan:* jallib <jal...@googlegroups.com> >>> >>> *Onderwerp:* Re: [jallib] PWM serial audio transmission >>> Still foggy, just wait a little longer with this case. >>> >>> Op zaterdag 26 maart 2022 om 20:05:55 UTC+1 schreef rob...@hotmail.com: >>> >>> Hi Hans, >>> >>> I hope you are getting well soon. Last update. I recorded the audio and >>> played it back to see if it works. >>> >>> And it seems to work but may need some fine tuning. In this video you >>> see the device in operation: https://youtu.be/w-j0ekk975g >>> >>> The yellow line on the oscilloscope is the audio signal and the blue >>> line the trigger signal. This trigger signal is also visible by the Amber >>> LED on the top right of the breadboard. >>> >>> I recorded the low tone (it is a video recording but I am only using the >>> audio) and switched from low tone to the high tone frequently. What you see >>> is that the signal of the high tone is smaller but it still works. You also >>> see that the refresh of the oscilloscope is a bit behind so the LED on the >>> breadboard shows the real trigger. I also attached two screenshots. You see >>> that the trigger response is quite fast (zoomed in) but with a high tone it >>> is not constant (see zoomed out) but that can be solved in software and >>> could be because the signal is smaller. Also I noticed that when no signal >>> is present the output is also high but that stops as soon as the low tone >>> is detected. >>> >>> So still a proof of concept but seems to do something. I also attached >>> the audio tone. Maybe lower tones would be better. >>> >>> For recording I just used the output of the PIC using a resistor divider >>> of 10 k with 100 Ohm and connecting that to the line in of my computer. For >>> playback I added an LM358 to amplify the input signal and I used the >>> headphone output. >>> >>> Kind regards, >>> >>> Rob >>> >>> >>> Op donderdag 24 maart 2022 om 12:47:49 UTC+1 schreef rob...@hotmail.com: >>> >>> Hi Marieke, >>> >>> Thanks for the update. Let's hope Hans recovers soon. >>> >>> Kind regards, >>> >>> Rob >>> >>> ------------------------------ >>> *Van:* 'Oliver Seitz' via jallib <jal...@googlegroups.com> >>> *Verzonden:* donderdag 24 maart 2022 07:37 >>> >>> *Aan:* jal...@googlegroups.com <jal...@googlegroups.com> >>> *Onderwerp:* Re: [jallib] PWM serial audio transmission >>> Altijd met Rust... >>> >>> It took me two weeks to think, code and test, and it will take more >>> weeks for proper documentation. So no need for you to hurry ;-) >>> >>> Greets, >>> Kiste >>> >>> Am Mittwoch, 23. März 2022, 22:36:19 MEZ hat hans < >>> hansvanve...@gmail.com> Folgendes geschrieben: >>> >>> >>> Hello everyone, >>> >>> My grandfather Hans has only one usable eye and has got an infection on >>> it. We have read your contributions and he is very happy with them. Sorry >>> but he can't work with it right now. >>> >>> Regards Marieke >>> >>> Op woensdag 23 maart 2022 om 17:22:42 UTC+1 schreef Kiste: >>> >>> And here's the receiver, and a sample file. Mp3 does work at 1200baud, >>> but you shouldn't use less than 128kbit for encoding. At 80kbit I only got >>> garbage. Volume must be reasonably high, slowly turn louder until the error >>> LED is constantly off. >>> >>> Don't send too much data back-to-back, have pauses of like 10 ms every >>> second (but keep the tone on all the time) >>> >>> Don't assume error-free transmission, send data multiple times and check >>> when receiving. >>> >>> Greets, >>> Kiste >>> >>> >>> >>> Am Sonntag, 20. März 2022, 13:22:14 MEZ hat 'Oliver Seitz' via jallib < >>> jal...@googlegroups.com> Folgendes geschrieben: >>> >>> >>> Hi all, >>> >>> here's my encoder. I looked for something similar to the 12F683 which >>> Hans has in stock, and found some 12F629, which should be quite compatible. >>> >>> >>> C1: minimum 1µF, no need to be polarized >>> R1:680R..1k >>> C2: 100nF >>> R2:1k..4k7 >>> D1=D2: 1N4148, 1N4001 or similar, silicon, not schottky >>> >>> This gives a frequency which a line (AUX) audio input should be able to >>> handle. The receiver will be the same kind of chip, but it must have a >>> comparator and a reference voltage module. TMR0 will be used. >>> >>> The transmitter will work on any 6 or 8 pin controller, as it doesn't >>> use any peripherals. >>> >>> Greets, >>> Kiste >>> >>> >>> -- >>> 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 jallib+un...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/jallib/189584036.471955.1647778917998%40mail.yahoo.com >>> >>> <https://groups.google.com/d/msgid/jallib/189584036.471955.1647778917998%40mail.yahoo.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 jallib+un...@googlegroups.com. >>> To view this discussion on the web visit >>> >>> https://groups.google.com/d/msgid/jallib/2bdcd32b-101d-4d29-8397-ddbb370e4788n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/jallib/2bdcd32b-101d-4d29-8397-ddbb370e4788n%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 jallib+un...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/jallib/1612276249.1299494.1648103861495%40mail.yahoo.com >>> >>> <https://groups.google.com/d/msgid/jallib/1612276249.1299494.1648103861495%40mail.yahoo.com?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >>> You received this message because you are subscribed to a topic in the >>> Google Groups "jallib" group. >>> To unsubscribe from this topic, visit >>> https://groups.google.com/d/topic/jallib/46GAtaPeJ_k/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> jallib+un...@googlegroups.com. >>> >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/jallib/bac9ec42-c8a3-4f2f-82b1-16b63d06b6f6n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/jallib/bac9ec42-c8a3-4f2f-82b1-16b63d06b6f6n%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 jallib+un...@googlegroups.com. >>> To view this discussion on the web visit >>> >>> https://groups.google.com/d/msgid/jallib/df201f79-6365-434b-b804-c948ddb305b3n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/jallib/df201f79-6365-434b-b804-c948ddb305b3n%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 jallib+un...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/jallib/523724631.932444.1649178768469%40mail.yahoo.com >>> >>> <https://groups.google.com/d/msgid/jallib/523724631.932444.1649178768469%40mail.yahoo.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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