Omar SobhandClaude Opus 4.8
45a8feb8b4
A pixel that bounces off the walls trailing its last 5 cells (a diagonal streak that bends on each bounce). Wired into the cycle between the knight-rider sweep and ripple. Compiled + flashed E2E (1637 bytes). Co-Authored-By: Claude Opus 4.8 <[email protected]>
51 lines
2.1 KiB
Markdown
51 lines
2.1 KiB
Markdown
# Uno Q LED-matrix sketches
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Animations for the Arduino Uno Q's built-in **13×8 monochrome blue** LED matrix
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(104 pixels on the STM32U585 MCU). The LEDs are physically blue and on/off only
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— there is **no colour or brightness control** in software.
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| Sketch | What it does |
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|--------|--------------|
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| `matrix_rain/` | Digital "rain" — per-column drops (head + short trail) at staggered speeds. |
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| `matrix_effects/` | Sampler that cycles rain → knight-rider sweep → comet → ripple → sparkle → wipe. |
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## How they work
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The matrix API is intentionally tiny: `matrix.begin()` and
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`matrix.loadFrame(const uint32_t frame[4])`. There is **no** `drawFrame`,
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`setPixel`, `clear`, etc. — those don't exist on this core and won't compile.
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So each frame is built in an `8×13` boolean `grid`, then packed into the
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`uint32_t[4]` (128 bits; 104 used) the driver wants — row-major, MSB-first, so
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pixel 0 is `frame[0]` bit 31:
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```cpp
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uint16_t bit = 0;
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for (uint8_t y = 0; y < 8; y++)
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for (uint8_t x = 0; x < 13; x++) {
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if (grid[y][x]) frame[bit >> 5] |= (1UL << (31 - (bit & 31)));
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bit++;
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}
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matrix.loadFrame(frame);
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```
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To make a new effect, just fill `grid` differently each frame and call `show()`.
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## Compile & flash (on the board, over adb)
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```sh
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S=<adb-serial>
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adb -s $S push matrix_effects /home/arduino/sketches/
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# TMPDIR override dodges the adb shell's /data/local/tmp (breaks arduino-cli)
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adb -s $S shell 'cd /home/arduino/sketches/matrix_effects && \
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TMPDIR=/tmp arduino-cli compile --fqbn arduino:zephyr:unoq --export-binaries .'
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adb -s $S shell 'arduino-flash /home/arduino/sketches/matrix_effects/build/arduino.zephyr.unoq/*.elf-zsk.bin'
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```
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`arduino-flash` runs OpenOCD (linuxgpiod SWD) and writes the sketch at
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**`0x80F0000`** — the address in the board's `boards.txt`
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(`unoq.upload.address`) for `arduino:zephyr` **0.51.0**. (Older QClaw docs cite
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`0x8100000`; that's stale for this core — trust `boards.txt`.) The flash ends
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with a reset, so the sketch runs immediately. Nothing may be visible for the
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first ~20–30 s after a cold power-on while the boot logo owns the matrix.
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