What is the best way to reset mt32-pi from other component?

[kunichiko]

I’m now developing Kepler-X multifunction expansion board for X68000. Kepler-X has many functions like PCM, FM Audio, MIDI, Memory etc.

Yesterday, I have successfully gotten mt32-pi work on the Kepler-X. MIDI signal is directly input to mt32-pi from FPGA. The I2S sound is back into FPGA and mixed with other sounds. Finally all sounds are output from S/PDIF or analog 3.5mm audio jack.

https://twitter.com/kunichiko/status/1603389470308716545?s=20&t=ZwFH2E3W7BbF0t5vO2oolw

It worked fine but I have one problem. If the reset button on the X68000 is pushed, all system components are restart except mt32-pi. So if I push reset button while playing game with MIDI sound, mt32-pi continue out some sounds because MIDI note off will never send to mt32-pi.

I also read the MT32PiHat schematic for MiSTer, but I couldn't understand the way to reset.
https://github.com/MiSTer-devel/Hardware_MiSTer/blob/master/Addons/MT32PiHat/MT32Pi_Main.SchDoc

So I want to ask someone, which way is the best to stop all notes on mt32-pi after system was resetted.

• Plan A: Send All Note Off message to all channels on mt32-pi after reset.
  • If mt32-pi can accept All Noted Off message correctly, it may work.
• Plan B: Send All Sound Off message to all channels on mt32-pi after reset.
  • If mt32-pi can accept All Noted Off message correctly, it may work.
• Plan C: Add reset or all note off input I/O pin on mt32-pi and connect reset (active low) signal to it
  • On this plan, mt32-pi have to poll the I/O.
• Plan D: Connect reset signal to RaspberryPi
  • RaspberryPi has reset terminal but it is not included by 40pin header. So I have to connect it by using cable.
• Plan E: Power down and up RaspberryPi by FPGA
  • I think it is bad idea...

Regards.

[dwhinham]

Hi @kunichiko,

libmt32emu and FluidSynth both implement the All Notes Off messages (if I remember correctly) and mt32-pi implements the All Sound Off message for both synthesizers, so Plan A and Plan B should work for your purposes.

Additionally, if you would like mt32-pi to warm-reboot, you can send SysEx message F0 7D F0 F7 to reboot the Raspberry Pi. More information is available at the wiki page.

[kunichiko]

Thank you for your quick response.

Sorry I had not read the wiki page which describes Custom System Exclusive messages mt32-pi supports.

I will try Plan A, B or SysEx message!