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