Another piece of text: So far I've done everything with MIDI. I used one midi channel for the actions with a general command type. Then 2 data, one for the device nr (16) and one for the command. (0-128) This has worked well for years, but it does require a complete MIDI sound package.
Op donderdag 24 februari 2022 om 16:55:46 UTC+1 schreef hans: > Hey , > I have tried a circuit with an MT8880 but the ICI has failed. I did hear > the 16 tones, but when I wanted to receive them, the chip gave up the ghost. > In theory I understand your suggestions well, but developing something > like this is not easy for me. I'm just a LEGO builder. > regards > Hans > > Op woensdag 23 februari 2022 om 19:30:37 UTC+1 schreef rob...@hotmail.com: > >> Hi Hans, Kiste, >> >> You can still by DTMF decoders and I assume also DTMF encoders. Just look >> at for example Aliexpress and type DTMF. >> >> But another suggestion. Many, many years ago I had built an Apple II and >> I used cassette tapes to store and load games which was using tones >> generated by the Apple II itself using two tones, one for high, one for low >> and one as a lead-in tone (not sure in the lead-in tone was another tone) >> to synchronze the start of the recorded program. You would not need this >> lead-in tone in your case >> >> So I think it may not be that complex: >> -) For recording on casette, generate this dual tone by the PIC via PWM >> or maybe it is also sufficient to generate one tone in case of a 1 and no >> tone in case of a 0 but I think this will be less reliable. >> -) For playback, measure the length of the recorded PWM tone. If is is >> within a certain range you accept it as a one and in case of two tones the >> lower tone could be zero and the higher tone is one. >> >> As long as the tone frequency is not too high, I think this could work. >> >> A more advanced solution would be to use a phase locked loop (PLL) but I >> am not sure if it will work. The PLL locks to the input signal so the >> voltage that controls the oscillator goes up and down to follow (lock on >> to) the input signal and this oscillator voltage signal could then be used >> by a comparator of the PIC to detect a high or low tone. You can also use >> the oscillator of the IC to generate the two tones by controlling the >> oscillator voltage by the PIC. A typical IC for that is the HEF4046. I have >> used this IC many many years ago too. This solution may be bit over the top >> since you only want a kind of trigger signal >> >> But maybe the first solution is more doable. Just give it a try. >> >> Kind regards, >> >> Rob >> >> ------------------------------ >> *Van:* 'Oliver Seitz' via jallib <jal...@googlegroups.com> >> *Verzonden:* woensdag 23 februari 2022 09:58 >> *Aan:* jal...@googlegroups.com <jal...@googlegroups.com> >> *Onderwerp:* Re: [jallib] PWM serial audio transmission >> >> Hi Hans, >> >> 20 years ago I would have suggested using DTMF, but the decoder chips are >> rare these days... >> >> PIC controllers include various peripherals which can be used to encode >> and decode DC-free signals (which, apart from the frequency below, say, >> 10kHz, is the requirement to be recorded as audio). On/off keying or >> frequency shift keying are the easiest, I think. Which chips are you going >> to use? >> >> Greets, >> Kiste >> >> Am Mittwoch, 23. Februar 2022, 09:15:43 MEZ hat hans < >> hansvanve...@gmail.com> Folgendes geschrieben: >> >> >> Hello everyone, >> I have been trying for a long time to place a serial signal on one track >> of an audio recording which I can read afterwards. To make all kinds of >> things happen at the same time as the audio is played. I have now tried to >> do this with the old modem system ( TCM3105) but it failed hopelessly. I >> read that there are also systems to do this using PWM. Does anyone have an >> idea? >> regards >> Hans >> >> -- >> 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/773ca37b-9bed-4349-a8eb-32a5d8973df6n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/jallib/773ca37b-9bed-4349-a8eb-32a5d8973df6n%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/201142693.752814.1645606718467%40mail.yahoo.com >> >> <https://groups.google.com/d/msgid/jallib/201142693.752814.1645606718467%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+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jallib/d4803c41-505a-4297-81d5-7be0ef06b112n%40googlegroups.com.
