Release DSPi Firmware v1.1.5 · WeebLabs/DSPi

The stable release closing out the v1.1.5 beta series. Everything below is new since v1.1.4.

Changes since v1.1.5-beta6

If you are already running beta6, this is the whole delta:

Significant PEQ and XO filter efficiency improvement (up to 25%)
Stereo upmixer gains a centre engine OFF mode, for surrounds-only upmixing that leaves left and right untouched.
New first-order high pass and low pass filter types.
Maximum selectable S/PDIF inputs raised from 3 to 4.
IR remote learns up to 16 buttons per receiver, up from 8.
Loudness reference SPL and intensity can now be bound to a knob, encoder, or remote button.

Everything else since beta6 was test-suite and internal DSP refactoring with no change in behaviour.

ADAT input: 8 channels over lightpipe, with master and slave clock modes (RP2350).
ADAT output: 8-channel lightpipe mirror of outputs 1-8 (RP2350).
I2S input, 2/4/6/8 channels, with a slave clock mode so an external master can drive BCK and LRCLK.
Up to 4 selectable S/PDIF inputs on the shared receiver, switchable at runtime.
USB input now runs 2, 4, 6, or 8 channels, with inputs treated as first-class channels throughout the mixer.
Master clock output on GPOUT, jitter-free at 128x and 256x at 48 kHz and 128x at 96 kHz.

Stereo upmixer: derives centre and surround channels from a stereo pair, with Passive and Logic engines, a centre presence bell, and a surrounds-only mode (RP2350).
Psychoacoustic bass: missing-fundamental harmonic generation per output, so small speakers get perceived bass below their real limit.
Crossover filters: Linkwitz-Riley, Butterworth, and Bessel, up to 4 bands per channel.
New filter types: Linkwitz Transform, first-order high pass, low pass, shelves, and all-pass, plus a second-order all-pass.
Volume leveller and crossfeed both go multichannel, with per-channel selection.
Loudness compensation is now per output, selectable by channel.
Onboard signal generator with 15 signal types, surviving preset loads.

Control Surfaces: wire your own buttons, switches, pots, rotary encoders, and LEDs to firmware parameters. Supports long press, double press, hold-to-repeat, momentary actions, encoder acceleration, PWM-dimmed meter LEDs, and per-slot names.
IR remote control: learn up to 16 buttons from any handset and bind each to a parameter.
Loudness reference SPL and intensity are now bindable to a knob, not just the on/off switch.
UART and I2C control interfaces, so an external microcontroller can drive the device without USB.
Output configuration can persist independently of presets, or travel with them.
Every pin setting accepts 0xFF to reset that pin to its default.
Per-band EQ bypass toggle.

Loudness compensation math corrected; the previous curve overshot by roughly 2.5x.
Outputs keep clocking through flash writes, so saving a preset no longer risks a click or a wedged DAC.
Fixed a crash during flash writes on RP2350 caused by unmasked interrupts.
Fixed full-volume noise when editing DAC mute settings during a flash write.
Fixed incorrect S/PDIF input levels on RP2040.
Fixed output type switching between S/PDIF and I2S.
Fixed global EQ bypass incorrectly gating outputs on RP2040.
Defeated auto-mute on 32-bit I2S DACs.
Click-free master and host volume control.
LG Sound Sync support for LG televisions.
USB descriptors corrected for Windows driver binding (WCID and MS OS 2.0).
Firmware now runs from flash with hot paths pinned in RAM, freeing about 70 KB of SRAM on RP2040 and 107 KB on RP2350.
Master volume no longer changes on a runtime preset load in independent mode.