DSPi Firmware v1.1.5-beta6

• New stereo upmixer (RP2350): derives centre, left surround and right surround from any stereo pair, with adaptive centre extraction and Dolby-style low-complexity surround.
• Upmixer centre presence control: a +/-12 dB 3 kHz bell on the extracted centre that pushes voices forward or sets them back; exactly bit-true at 0 dB.
• Fixed persistent full-scale noise after a preset rename or Control Surface save; every settings write now ends in a clean, phase-aligned output restart.
• Outputs now keep clocking through flash writes, so saving presets and changing settings no longer causes pops, SPDIF receiver unlocks, or DACs locking into distortion.
• Fixed an RP2350 crash during flash writes caused by UART, I2C and ADC interrupts staying live through the blackout window.
• IR remote now distinguishes a held button from a fast re-press, so quick repeat presses no longer need a 250 ms gap.
• Control Surfaces can now bind the stereo upmixer, psychoacoustic bass, output delay (in ms) and preset reload.
• Any pin assignment can now be reset to its firmware default by writing 0xFF.