Connecting mt32-pi to Sound Blaster Live 5.1! Digital Extension

[hjnijlunsing]

Hi!

I was wondering while looking at this video https://www.youtube.com/watch?v=rVNSyRAwVXs @1m49.
There seems to be a 40 pin-layout for the Sound Blaster Live 5.1; which features:

• GND
• 5V
• Midi In UART
• Midi Out UART
• I2S Audio Input

Thus I was wondering if I could use a Pi Zero 2 and connect this directly with the GPIO pins to the above pins of the SB Live! will this instantly give my SB Live 5.1 MT32 capabilities? ;-)
This would resolve my issues in getting it to work with SoftMPU and having a special DAC for the Pi for feeding the sound back to the line input.

(Not sure if the UART will use 5v or 3.3v; that might be an issue)

Kr,

Harm Jan

[dwhinham]

It could work, but I would not attempt anything without a level shifter as it's likely that the Live! uses 5V signalling.

If in doubt, use a multimeter.

[hjnijlunsing]

Thanks! Wouldn't I need to build the same circuit as this? https://github.com/dwhinham/mt32-pi/wiki/GPIO-MIDI-interface (So with the HL11 and capacitors etc? Or would that be overkill?)

[dwhinham]

The circuit in the wiki is for creating a standard MIDI DIN interface for connecting off-the-shelf MIDI devices to the Raspberry Pi, so you don't need this.

You can just wire the SB Live! UART to the Pi UART, RX to TX and vice versa - but through a level shifter. You can't skip the level shifter unless you are 100% certain the SBLive is using 3.3V on all the signals. Otherwise you will be the proud owner of a dead Raspberry Pi.

Wiring would look something like:

Pi GND --> Level shifter GND <-- SBLive GND
Pi 3.3V --> Level shifter LV | Level shifter HV <-- SBLive 5V
Pi UART RX --> Level shifter LV1 | Level shifter HV1 <-- SBLive UART TX
Pi I2S CLK --> Level shifter LV2 | Level shifter HV2 <-- SBLive I2S CLK
Pi I2S FS --> Level shifter LV3 | Level shifter HV3 <-- SBLive I2S FS
Pi I2S DIN --> Level shifter LV4 | Level shifter HV4 <-- SBLive I2S DOUT

The rest is up to you, you'll need to figure out how to convince the SBLive to record/monitor the I2S input, etc. But on paper it should work; probably similar to how you set up one of the old Live Drives.