GuitarPaul
New member
Dear swarm intelligence!
I've build a fine working hexaphonic guitar pitch to midi prototype years ago on a teensy 3.2 with arduino, it reads individual string signals via 6 ADC inputs, an outputs MIDI over serial.
The ADC is invoked using the ADC.h library, doing single conversion on a timer interrupt.
Every interrupt the next string to convert tis pushed like this:
ADC0_SC1A = nextStringlToConvert+ ADC_SC1_AIEN;
Every string datastream then is upsampled and filtered with shift and multiply integer arithmetic.
The MIDI output is serial, and running in loop().
Between the timed ADC usage and the loop a simple message system creates a FIFO.
So sending the MIDI over serial doesn't get in the way of the timer interrupt.
Now I'm reviving this prototype, and Im thinking of upgrading to teensy 4.1, getting rid of the mul and shift and hoping to improve several things.
No here is my question:
- Can I use a timer interrupt alongside MIDI USB on a teensy4.1?
- or is there a known DMA scheme for getting this multiplexed stream out of ADC?
Thanks in advance!
Paul
I've build a fine working hexaphonic guitar pitch to midi prototype years ago on a teensy 3.2 with arduino, it reads individual string signals via 6 ADC inputs, an outputs MIDI over serial.
The ADC is invoked using the ADC.h library, doing single conversion on a timer interrupt.
Every interrupt the next string to convert tis pushed like this:
ADC0_SC1A = nextStringlToConvert+ ADC_SC1_AIEN;
Every string datastream then is upsampled and filtered with shift and multiply integer arithmetic.
The MIDI output is serial, and running in loop().
Between the timed ADC usage and the loop a simple message system creates a FIFO.
So sending the MIDI over serial doesn't get in the way of the timer interrupt.
Now I'm reviving this prototype, and Im thinking of upgrading to teensy 4.1, getting rid of the mul and shift and hoping to improve several things.
No here is my question:
- Can I use a timer interrupt alongside MIDI USB on a teensy4.1?
- or is there a known DMA scheme for getting this multiplexed stream out of ADC?
Thanks in advance!
Paul