Wow - that’s quite some wiring!
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Wow, it got a whole lot more complicated after I realised I didn’t understand how polymod was implemented on a prophet like the 5 or 600, so after some deliberation and the addition of a pair of 4016 chips I was able to use the 8 existing spare 4053 switch segments for the polymod to filter and the 4016 for the polymod to DCO1. Both polymod filter envelopes and DCO2 audio have depth controls. So it’s like the P600 polymod section as I ran out of space to implement the full P5 with PWM polymod. Dual FV1 effects processors with 32 effects are constructed to the right along with a stereo amplitude mod section (not wired up yet).
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Just testing multiple 2.0" ST7789 displays for my next synth. I plan to use upto 8 to display all the parameters of the synth like the AX-80 does. Currently just repurposing the code from the last PolyZero build to throw something onto the 240*320 displays, basically sending MIDI cc messages on a private bus for the Teensy to interpret and update the relevant screen inturn. Seems smooth enough and it’s not like there will be tons of traffic. Just patch loading and the parameter tweaks. I’m going to turn the bars vertical like the AX-80 and add some graphics. Still short of 4 displays for the full test.
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More displays arrived today, a different brand but still ST7789 based 2.0" and I soon rewired to add 8 displays.
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wow indeed, it’s phenomenal work , everone else would just do 3 orders to JLC till they got something with only a few bodge wires.
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I understand, but this design changed about 5 or 6 times on the fly with parts being removed and new ones added, I would have probably gone through 20 or so iterations of a PCB design, build and test before I got what I wanted.
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Demux section taking shape, 64 channels of CV, 56 channels of shift registers, 4 LFOs and 2 noise circuits.
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Completed (hardware) bi-timbral synth controller. 64 channels of CV split upper and lower, plus 56 channels of shift registers to control digital stuff and drive 6* r2r DACs as I have no more channels left on the demux and little room for another 24 pin mux and associated sample and holds. 4* LFOs for FM, TM, AM and PWM upper and lower. 2* noise circuits for upper and lower plus associated VCAs to control levels etc and offsets so they can be used on 3.3v processors.
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Ha! Love it! Well done Craig. Again, I want to print out the pictures and put them on the wall!
Nastaviti!
продовжуй, це чудово!!
…just keep going 
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Still needs a lot of work, but I’ve managed to get the 9 parameter displays up and running, display 10 (the first one) is actually controlled by another processor and is for patch management.
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I’ve spent the last week or so messing around with menus, adding all of the functions of the synth into the display board etc. Also troubleshooting issues with wire distances on 74HC165 chips for reliable operation, problems with sysex transfers for faster patch loading into the displays, battling the lack of a decent i2c slave implementation on the Teensy 4.1 etc. But now I’ve got to the point where I can power on the voice board with the controller and test the first phases of functionality, basically everything that goes over midi from the controller to the voice chips, so notes, octave switching, glide control, pulse width and modulation, keytrack control etc. I thought I hadn’t implemented a keytrack switch, only the level, but it turns out I had both in my DCO code, so now I will add a keytrack switch to the controller.
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