v0.7.1

Added

• "Loading" message when switching SoundFonts.

Changed

• Update to GeneralUser GS v1.511.
  • This is a currently-unpublished version from the author, who has made several important fixes to the SoundFont to improve compatibility with FluidSynth v2.1.0+.
• Update to circle-stdlib v15.5/Circle Step 43.2.
• Part level meters in SoundFont mode now have "bases".

Fixed

• Incorrect -dirty suffix on version string on clean builds (again!).
• Crash when using USB MIDI interface in SoundFont mode, or when resuming from power saving mode.
• Hang on startup if unsupported LCD size is set in configuration file.

v0.7.0

Added

• FluidSynth synthesizer engine v2.1.5 for using SoundFonts for General MIDI support and more.
  • You can switch between MT-32 and SoundFont mode at runtime using SysEx.
  • SoundFonts can be switched at runtime using SysEx, with some caveats for large SoundFonts (see FAQ section of README).
  • New configuration file options for changing default synthesizer and SoundFont.
• GeneralUser GS v1.471 included as default SoundFont - many thanks to S. Christian Collins for kindly giving permission!
• Ability to invert the display orientation for SSD1306 (new configuration file option).
• Support for 64 pixel high SSD1306 OLED displays - many thanks to @ctrl_alt_rees for donating a screen!
• Ability to set I2C clock speed (new configuration file option).
  • This is useful for allowing larger displays to refresh at a faster speed; see config file for details.
• Power saving mode with configurable timeout (new configuration file option).
  • The CPU clock speed will be lowered, audio device stopped, and LCD backlight turned off (when possible) after a configurable number of seconds to save energy.
  • Any MIDI activity will instantly bring the system out of power saving mode.
• Undervoltage/throttling detection - mt32-pi will now warn the user when the firmware detects an undervoltage/CPU throttling condition.

Changed

• Update to circle-stdlib v15.4.
• New multi-core architecture; audio rendering and LCD updates moved to their own dedicated CPU cores, leaving MIDI and interrupt processing on the primary core.
• Kernels for Pi 3 and 4 are now compiled for AArch64 (64-bit) for better performance.
  • When upgrading, you must replace the config.txt file on your SD card and add the new armstub8-rpi4.bin file for Pi 4.
  • You should remove old kernel*.img files from your SD card.
  • It's recommended that you clear your SD card (except for your roms directory) and reconfigure mt32-pi for this release.
• Synth engines now compiled with more aggressive optimizations enabled to benefit from ARM NEON instructions.
• Due to the above three changes, it's possible that Raspberry Pi 2 may be more usable with this release, but this is untested.
• Kernel size significantly reduced by removing mt32emu ROM loader dependency on C++ iostreams.
• Improved layout of 4-line HD44780 LCD.
  • MT-32 status line moved to bottom row.
  • Part levels now 3 rows high.
• Default sample rate and chunk size reduced to 48000Hz and 256 samples.

Fixed

• SSD1306 text alignment was off by one pixel.
• SSD1306 part level meters' top pixels would flicker with long sustained notes.
• Part level meters would suddenly snap to a lower level if a quiet note followed a loud note instead of falling off.
• Possibility of overflowing text in HD44780 Print() function.

v0.6.2

Fixed

• USB MIDI was broken since 0.6.0.

Changed

• SSD1306 font updated to perfectly match the original MT-32's Sanyo DM2011 font.

v0.6.1

Changed

• Update to libmt32emu v2.4.1.
• Update to circle-stdlib v15.3/Circle Step 43.1.
• Update to inih r52.
• Boot speed improved by another ~0.3 seconds when usb = on thanks to improvements in Circle Step 43.1.
  • If updating from an old version, make sure you replace config.txt to benefit from a couple of other boot optimizations.

Fixed

• Correct version string is now extracted from ROM 2.04 when switching to it.
• The none option for i2c_dac_init was broken in v0.6.0.
• Spacing between status row text and part level meters on SSD1306 improved.

v0.6.0

Added

• Ability to configure initial MIDI channel assignment (new configuration file option).
• Ability to set custom baud rates for GPIO MIDI (new configuration file option).
  • This could be useful for those wanting to use SoftMPU's serial MIDI mode.
• Multiple ROM sets can now be used and switched between using custom SysEx commands. See new README.md section and config file for full details.
  • Please move your MT32_CONTROL.ROM and MT32_PCM.ROM into a new subdirectory called roms.
  • For now, the old locations are still checked as a fallback, but this may be removed in a later version.

Changed

• Update to circle-stdlib v15.2/Circle Step 43.
• Boot speed improved by ~0.5 seconds by using start_cd.elf/start4cd.elf and fixup_cd.dat/fixup4cd.dat.
  • If updating from an old version, make sure you replace config.txt and add the new *.elf and *.dat files when updating your SD card to benefit from this.
• LCD/OLED part level meters moved to the upper row(s).
• Config file parsing now more efficient.

Fixed

• Left/right channels were backwards when using PWM (headphone jack) - thanks @ctrl_alt_rees and YouTube viewers.

v0.5.0

Added

• Program change messages are now shown on the LCD.

Changed

• Activity LED now flashes when other types of messages are received (e.g. SysEx or control changes).

Fixed

• Complete rewrite of the MIDI parser code.
  • USB and GPIO MIDI streams are now handled by a single code path.
  • Corrupt SysEx messages (e.g. from cheap/no-name MIDI interfaces) will no longer cause mt32-pi to hang (issue #25).
  • 2-byte Running Status messages are now handled correctly (issue #26).
• Active Sensing race condition fixed and timeout increased to 330ms as recommended by the MIDI 1.0 Specification.

v0.4.0

Added

• Software "MIDI thru" for GPIO interface (new configuration file option).

Changed

• Update to circle-stdlib v15.1/Circle Step 42.1.
• Enhanced error reporting for GPIO MIDI parser.

Fixed

• Hanging/missing notes when GPIO MIDI interface used with some modern MIDI sources that transmit using Running Status optimizations.
  • Many thanks to @thorr2, @nswaldman, @icb-, @glaucon1984, @Braincell1973, @Higgy69, and @olliraa for patiently reporting, testing and brainstorming the cause of this critical issue.
• MIDI messages could be passed to mt32emu with the wrong length.

v0.3.1

Added

• Missing sample [lcd] config section from mt32-pi.cfg.

Fixed

• Incorrect -dirty suffix on version string on clean builds.
• Possibility of overflowing text in SSD1306 Print() function.
• Rhythm part on SSD1306 was inverted on activity instead of being blocked out.

v0.3.0

Added

• Initial support for HD44780 (4-bit direct and I2C) character LCDs and SSD1306 128x32 graphical OLEDs.
  • Configuration file changes required - please check documentation.

v0.2.1

Fixed

• Crash when using resampler_quality = none - thanks @nswaldman.