prosolis
469b321a40
Raspberry Pi supply is unreliable, and Circle is Broadcom-only - there is no Allwinner or Rockchip support anywhere in its tree, so an Orange Pi is not a board swap but a restart on an unproven base. RP2040/RP2350 is the better answer: available, ~$4, and a better fit for this job than the Zero ever was. Structure. All the visualizer logic moves to src/ and is now platform-independent, depending only on ILEDStrip (four methods) with MIDI pushed in via OnMIDIPacket(). Each platform supplies a backend and a main loop. The Circle build is unchanged in behaviour and still produces both kernel images. Pico backend: - WS2812B from a PIO state machine, which clocks the 1.25us bit cell directly rather than faking it with 8 SPI bytes per data bit as the Circle build must. - TinyUSB MIDI 1.0 device. Enumerates as an ordinary ALSA port, as the Circle gadget does. Packet framing comes from the USB MIDI Code Index Number rather than being re-derived. - Mount, unmount, suspend and resume all clear held notes, so a chord held when the host goes away cannot stay lit. - Latch spacing is enforced against a timestamp, so a caller cannot start a frame inside the WS2812B reset window. Verified: builds clean for both pico (RP2040, 30052 bytes) and pico2 (RP2350, 28284 bytes), no warnings from project sources, and the Circle build still produces kernel.img and kernel7.img. Tests pass across nine configurations. Incidental findings. PIO frees both hardware SPI blocks; on a Pi Zero Circle exposes only one SPI master (DEVICES=1 for RASPPI<4) and the WS2812B driver monopolises it, so a display and the strip could not coexist there. RP2040/ RP2350 also support USB host and, on the W variants, BLE via btstack - both of which section 3a records as impossible on Circle. Also documents a known limitation found while looking at calibration: the note-to-LED map is linear in semitone index, but a keybed is not. 52 white keys span the same 1222mm, making one white key ~3.38 LEDs rather than 2. The error drifts within each octave, worst at F, by up to ~0.87 LEDs (~6mm) even after an optimal offset and scale. A geometric map would remove it. Not yet implemented. Claude-Session: https://claude.ai/code/session_01TVCB25LBsmeteWvaSMz4Ne
102 lines
2.2 KiB
C
102 lines
2.2 KiB
C
//
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// usb_descriptors.c
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//
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// A single USB MIDI 1.0 streaming interface. From the PC this enumerates as
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// an ordinary ALSA MIDI port, exactly as the Circle gadget build does.
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//
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#include "tusb.h"
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#define USB_VID 0xCafe
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#define USB_PID 0x4001
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#define USB_BCD 0x0200
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static const tusb_desc_device_t desc_device =
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{
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.bLength = sizeof (tusb_desc_device_t),
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.bDescriptorType = TUSB_DESC_DEVICE,
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.bcdUSB = USB_BCD,
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.bDeviceClass = 0x00,
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.bDeviceSubClass = 0x00,
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.bDeviceProtocol = 0x00,
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.bMaxPacketSize0 = CFG_TUD_ENDPOINT0_SIZE,
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.idVendor = USB_VID,
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.idProduct = USB_PID,
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.bcdDevice = 0x0100,
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.iManufacturer = 0x01,
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.iProduct = 0x02,
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.iSerialNumber = 0x03,
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.bNumConfigurations = 0x01
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};
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const uint8_t *tud_descriptor_device_cb (void)
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{
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return (const uint8_t *) &desc_device;
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}
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enum { ITF_NUM_MIDI = 0, ITF_NUM_MIDI_STREAMING, ITF_NUM_TOTAL };
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#define EPNUM_MIDI_OUT 0x01
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#define EPNUM_MIDI_IN 0x81
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#define CONFIG_TOTAL_LEN (TUD_CONFIG_DESC_LEN + TUD_MIDI_DESC_LEN)
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static const uint8_t desc_configuration[] =
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{
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TUD_CONFIG_DESCRIPTOR (1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, 0x00, 100),
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TUD_MIDI_DESCRIPTOR (ITF_NUM_MIDI, 0, EPNUM_MIDI_OUT, EPNUM_MIDI_IN, 64)
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};
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const uint8_t *tud_descriptor_configuration_cb (uint8_t index)
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{
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(void) index;
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return desc_configuration;
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}
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static const char *const string_desc_arr[] =
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{
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(const char[]) { 0x09, 0x04 }, // 0: English (0x0409)
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"PianoLED", // 1: Manufacturer
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"Piano LED Visualizer", // 2: Product
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"000000000001", // 3: Serial
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"Piano LED MIDI", // 4: MIDI interface
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};
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static uint16_t _desc_str[32];
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const uint16_t *tud_descriptor_string_cb (uint8_t index, uint16_t langid)
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{
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(void) langid;
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uint8_t chr_count;
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if (index == 0)
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{
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memcpy (&_desc_str[1], string_desc_arr[0], 2);
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chr_count = 1;
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}
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else
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{
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if (index >= sizeof (string_desc_arr) / sizeof (string_desc_arr[0]))
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{
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return NULL;
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}
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const char *str = string_desc_arr[index];
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chr_count = (uint8_t) strlen (str);
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if (chr_count > 31)
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{
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chr_count = 31;
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}
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for (uint8_t i = 0; i < chr_count; i++)
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{
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_desc_str[1 + i] = str[i];
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}
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}
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_desc_str[0] = (uint16_t) ((TUSB_DESC_STRING << 8) | (2 * chr_count + 2));
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return _desc_str;
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}
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