BloodyCactus wrote:how are you reading midi? is it external fed into the pi uart?
Nope... I'm aware of the timing and other issues with attempting to use a GPIO pin for MIDI I/O, even a UART on the RPi at non-standard baud rate, and intend to use an Atmega 328 dedicated for that purpose, connected to the Raspberry Pi (or whatever SoC I end up using) UART. I use an Atmega 328 as a MIDI interface on my computer now and it works fantastically.
BloodyCactus wrote:the onboard audio is really bad to the point one shouldnt use it.
BloodyCactus wrote:i _ASSUME_ the wavetable l/r output pins are analogue sound...
d0pefish wrote:I totally agree with disregarding the internal audio - it is dreadful.
The L/R pins on the Wavetable are definitely analog... they go right into a dedicated mixer channel on the sound card (usually). And yeah, I thought about this, and this is one of the items I've counted against using a Raspberry Pi (or, more specifically, the Broadcom BCM2835) for this purpose. In all of the Raspberry Pis the audio out comes off of a filtered PWM output... limited, and not the greatest sound quality for sure. The other SoC I'm looking at (Allwinner H2+) includes a built-in 24-bit DAC with 92dB noise floor... pretty respectable. This is yet another reason to use that SoC rather than the Broadcom, even if the Broadcom has the compute power required (which I'm still not 100% sure at this point).
BloodyCactus wrote:Id also suggest pulse then you get the whole world of jackd/midictrl and mapping and such.
Wayyy too much overhead and complication. I have to write a custom shim/glue software anyway to interface the Atmega chip to ALSA, as well as the custom host-chip user interface I want to write, so this program will also manage the necessary ALSA patches as required for MUNT.
BloodyCactus wrote:
I've seen a lot of resources related to the WaveBlaster header, but not this one. This looks great. Thanks!
d0pefish wrote:I'm using a USB MIDI interface, so I'm not hitting the GPIO, and the speed issues are there when outputting with internal audio and USB audio (I have a few different kinds of USB audio device).
The USB MIDI interface might be the issue. Unless you are using a really high end one like a Mark of the Unicorn, or good Roland, buffer and timing issues could be the culprit. This is one of the reasons why I developed my own using an Atmega 328.