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MIDIBox SID using two Prop 1s — Parallax Forums

MIDIBox SID using two Prop 1s

shadoclawshadoclaw Posts: 10
in Propeller 1

So I decided to annoy TK and Wilba again.

Been working on a MIDIBox SID idea for about a week now. And of course, I'm using SIDCog, because real SIDs and even Swinsids are more expensive than prop 1s.

Concept is this: port the SID V2 firmware to a core module based around a STM32103 "Blue Pill". Iic 4*20 LCD, 2 gig SD card for patch storage, DIN/OUT modules for buttons and LEDs. 3 USARTs allowing for multiple assignable 5 pin MIDI inputs, possibly more UARTs via iic modules.

Currently, the idea is to connect 2 prop boards (my old discontinued Prop Project Board and a board built around a Flip) to the Blue Pill core module via SPI (though the blue pill supports CAN natively, the Prop 1 does not, and UART and iic connections were a no go as well due to hardware and software conflicts). Each prop will run 4 SIDCogs simultaneously in mono, with each SIDCog having it's own audio output pin leading to a resistor and cap output network based roughly on the audio output circuit from the prop cookbook (I changed the 10 uF electrolytic cap to a 22uF to beef up the output). These circuits will feed 8 1/4" output jacks, which can then be patched into an 8*4 patch bay powered by two tl072s and summing into a pair of 1/4" stereo jacks for ultimate output.
This layout uses 8 total pins from the Prop (4 audio and 4 for the SPI interface), annnnd I'm not touching P28-31 with a ten foot pole to avoid startup conflicts. The remaining 20 gpio pins will be pulled up with 10k resistors and used as digital inputs for buttons and encoders, to communicate with the blue pill like a shift register on cocaine through the SPI interface.

I have the blue pill module built, the project board stuffed, and I have spin objects to run the 4 sidcogs and the SPI interface. I'll be designing and building the FLIP module in the next few days, and then the hard part begins: porting and modifying the MIDIBox SID firmware to suit the needs of the project, then building the rest of the hardware and the enclosure. This project could take several months, but it should be worth it in the end, if only to prove to myself that I can do it.
Cheers!

Comments

  • TonySpinerTonySpiner Posts: 50

    @shadoclaw said:
    So I decided to annoy TK and Wilba again.

    Been working on a MIDIBox SID idea for about a week now. And of course, I'm using SIDCog, because real SIDs and even Swinsids are more expensive than prop 1s.

    Concept is this: port the SID V2 firmware to a core module based around a STM32103 "Blue Pill". Iic 4*20 LCD, 2 gig SD card for patch storage, DIN/OUT modules for buttons and LEDs. 3 USARTs allowing for multiple assignable 5 pin MIDI inputs, possibly more UARTs via iic modules.

    Currently, the idea is to connect 2 prop boards (my old discontinued Prop Project Board and a board built around a Flip) to the Blue Pill core module via SPI (though the blue pill supports CAN natively, the Prop 1 does not, and UART and iic connections were a no go as well due to hardware and software conflicts). Each prop will run 4 SIDCogs simultaneously in mono, with each SIDCog having it's own audio output pin leading to a resistor and cap output network based roughly on the audio output circuit from the prop cookbook (I changed the 10 uF electrolytic cap to a 22uF to beef up the output). These circuits will feed 8 1/4" output jacks, which can then be patched into an 8*4 patch bay powered by two tl072s and summing into a pair of 1/4" stereo jacks for ultimate output.
    This layout uses 8 total pins from the Prop (4 audio and 4 for the SPI interface), annnnd I'm not touching P28-31 with a ten foot pole to avoid startup conflicts. The remaining 20 gpio pins will be pulled up with 10k resistors and used as digital inputs for buttons and encoders, to communicate with the blue pill like a shift register on cocaine through the SPI interface.

    I have the blue pill module built, the project board stuffed, and I have spin objects to run the 4 sidcogs and the SPI interface. I'll be designing and building the FLIP module in the next few days, and then the hard part begins: porting and modifying the MIDIBox SID firmware to suit the needs of the project, then building the rest of the hardware and the enclosure. This project could take several months, but it should be worth it in the end, if only to prove to myself that I can do it.
    Cheers!

    Very interesting project Shadoclaw, keep us posted on progress!

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