I already know something like this is possible and will be basing my path forward on successful projects like Ornament and Crime https://github.com/mxmxmx/O_C My own experience with microcontrollers is a graduate level mechatronics course that mainly focused on motor controllers and the like as well as some hobby stuff. My coding experience is every day on the job, so no worries there. I also have built a number of synthesizer modules from schematics; and my own variations on designs.
What I want to know is if my approach is sound. For components I am considering:
DAC8568 an octal 16 bit DAC http://www.ti.com/lit/ds/symlink/dac8568.pdf
ADS8332 an octal 16 bit ADC http://www.ti.com/lit/ds/symlink/ads8332.pdf
3.5" TFT 320x240 Touchscreen HXD8357D HXD8357D https://www.adafruit.com/products/2050
Extra SPI memory with 6 23LC1024 https://github.com/FrankBoesing/memoryboard
Possibly extension with capacitive touch interface through SPI.
Various opamps to scale and offset voltages.
I could draw out a schematic, but it would look quite similar to the Ornament and Crimes linked above.
Questions:
My first questions are how would you lay out the SPI interface? From what I have been reading it would be a good idea to put the TFT on SPI0 by its self (very interested in the high performance DMA library). Would it be best to put the DAC and ADC on separate SPI? Or will they play nice at 44khz on the same SPI? Basically is there enough SPI I/O to go around at audio rates?
Concept of Operations:
An image of the module layout I am planning
http://www.sinphi.com/synths/effluvium/DSP_001.png
At the core it is a Teensy 3.6 microcontroller board with 16 bit ADC/DAC and enough memory for up to 9 seconds of audio delay or sampling. The 3.5 inch touch screen allows for quick and direct selection of options. The I and J encoders allow for selection within those parameters. Pressing J progresses into a menu and I backs out. Holding I for two seconds will return to the root menu. The I encoder is used to scroll through parameters and the J encoder is used to edit the parameter.
There are 12 inputs: 4 trigger/gate inputs and 8 ADC configurable control voltages. The 8 DAC outputs are capable of 10 Volt peak-to-peak operation. Triggers can be used for clocks, event triggers, envelope gates, retrigger, etc. The ADC inputs accept audio or control voltages (CV). The outputs can be bipolar or unipolar depending on the application with CV or audio output.
What I want to know is if my approach is sound. For components I am considering:
DAC8568 an octal 16 bit DAC http://www.ti.com/lit/ds/symlink/dac8568.pdf
ADS8332 an octal 16 bit ADC http://www.ti.com/lit/ds/symlink/ads8332.pdf
3.5" TFT 320x240 Touchscreen HXD8357D HXD8357D https://www.adafruit.com/products/2050
Extra SPI memory with 6 23LC1024 https://github.com/FrankBoesing/memoryboard
Possibly extension with capacitive touch interface through SPI.
Various opamps to scale and offset voltages.
I could draw out a schematic, but it would look quite similar to the Ornament and Crimes linked above.
Questions:
My first questions are how would you lay out the SPI interface? From what I have been reading it would be a good idea to put the TFT on SPI0 by its self (very interested in the high performance DMA library). Would it be best to put the DAC and ADC on separate SPI? Or will they play nice at 44khz on the same SPI? Basically is there enough SPI I/O to go around at audio rates?
Concept of Operations:
An image of the module layout I am planning
http://www.sinphi.com/synths/effluvium/DSP_001.png
At the core it is a Teensy 3.6 microcontroller board with 16 bit ADC/DAC and enough memory for up to 9 seconds of audio delay or sampling. The 3.5 inch touch screen allows for quick and direct selection of options. The I and J encoders allow for selection within those parameters. Pressing J progresses into a menu and I backs out. Holding I for two seconds will return to the root menu. The I encoder is used to scroll through parameters and the J encoder is used to edit the parameter.
There are 12 inputs: 4 trigger/gate inputs and 8 ADC configurable control voltages. The 8 DAC outputs are capable of 10 Volt peak-to-peak operation. Triggers can be used for clocks, event triggers, envelope gates, retrigger, etc. The ADC inputs accept audio or control voltages (CV). The outputs can be bipolar or unipolar depending on the application with CV or audio output.
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