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docs(firmware): record Spike 5 partial refresh + typing

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Julien Calixte
2026-07-05 00:00:16 +02:00
parent 25665561cd
commit 17fd663c85
1 changed files with 21 additions and 10 deletions
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31
firmware/README.md
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@@ -7,13 +7,24 @@ context.
## Current state
**Spike 4 — USB host keyboard: verified 2026-07-04.** `main.rs` runs the USB
host bring-up: [`src/usb_kbd.rs`](src/usb_kbd.rs) drives the ESP-IDF USB Host
Library directly through the raw `esp-idf-sys` bindings (no managed HID class
driver), enumerates an attached keyboard, claims the boot-keyboard interface,
switches it to boot protocol, and polls the interrupt-IN endpoint — decoding
each 8-byte report into modifiers + keycodes logged over UART. Verified with a
`19f5:3255` keyboard: keystrokes, modifiers, and rollover all decode correctly.
**Spike 5 — partial refresh + typing: verified 2026-07-04.** `main.rs` wires
the keyboard to the panel: [`src/usb_kbd.rs`](src/usb_kbd.rs) feeds decoded
key-downs (US layout, edge-detected) into a queue, and the main loop keeps a
wrapped, scrolling text buffer that it draws with a **partial refresh**
(`Epd::display_frame_partial`) per keystroke batch, plus a periodic full
refresh to clear ghosting. First spike where input and output run together.
Measured on the bench at 4 MHz SPI: partial refresh ~630 ms, full ~1870 ms —
the partial waveform (~490 ms, all 272 rows) dominates. Follow-up: windowed-Y
partial refresh (drive only the edited line's rows) to cut per-keystroke
latency.
**Spike 4 — USB host keyboard: verified 2026-07-04.**
[`src/usb_kbd.rs`](src/usb_kbd.rs) drives the ESP-IDF USB Host Library directly
through the raw `esp-idf-sys` bindings (no managed HID class driver), enumerates
an attached keyboard, claims the boot-keyboard interface, switches it to boot
protocol, and polls the interrupt-IN endpoint — decoding each 8-byte report into
modifiers + keycodes. Verified with a `19f5:3255` keyboard: keystrokes,
modifiers, and rollover all decode correctly.
Hardware: flash + serial over the CP2102 "UART" port (console = UART0,
independent of the USB PHY), keyboard on the native "USB" port. The keyboard
@@ -23,8 +34,8 @@ higher-power/RGB devices).
**Spike 2 — EPD: verified 2026-07-04.** The GDEY0579T93 e-paper panel is
driven through the thin dual-SSD1683 driver in [`src/epd.rs`](src/epd.rs)
(ported from GxEPD2's `GxEPD2_579_GDEY0579T93`; kept compiled but unused while
Spike 4 owns `main.rs`). Verified on the bench rig over 4 MHz SPI:
(ported from GxEPD2's `GxEPD2_579_GDEY0579T93`). Verified on the bench rig over
4 MHz SPI:
- **2a — uniform fill:** clean full-panel white ↔ black refreshes, proving
the wiring, both cascaded controllers, RAM addressing, and the full
@@ -48,7 +59,7 @@ reseat the jumpers (CS first) before debugging code.
Next up per
[`docs/v0.1-mvp-technical.md`](../docs/v0.1-mvp-technical.md#hardware-bring-up-order):
partial refresh, Wi-Fi/TLS, gitoxide push; SD is deferred.
Wi-Fi/TLS, gitoxide push; SD is deferred.
**Spike 1 — Blink: verified 2026-07-04.** GPIO 2 + on-board WS2812 toggled
at 1 Hz with `blink N` on USB-serial, proving toolchain, esp-idf link, and