first version

README.md

@@ -1,2 +1,131 @@
-# kuzu
+# 光 Hikari
 
+A custom WS2812 LED badge powered by a [Seeed XIAO (BLE/RP2040/ESP32C3/...)](https://wiki.seeedstudio.com/SeeedStudio_XIAO_Series_Introduction/) and written in [TinyGo](https://tinygo.org).
+
+The PCB hosts 20 RGB LEDs arranged in a **4 rows × 5 columns** grid behind a frosted 3D-printed diffuser. A single button cycles through lighting effects.
+
+
+![Video 3](assets/videogif3.gif)
+
+
+---
+
+## Hardware
+
+| Component | Note |
+|-----------|-----|
+| Hikari PCB | in hardware/pcb folder |
+| 3D printed files | in hardware/STL folder |
+| Flathead screw 2.1x10 | 4x |
+| 20 × WS2812 LEDs (4 rows × 5 cols) | D6 |
+| Tactile button | D3 |
+| Qwiic / StemmaQT connector | D4 & D5 (I²C) |
+| Passive buffer | D7 |
+
+---
+
+## Effects
+
+Each press of the button advances to the next effect. The sequence cycles endlessly.
+
+| # | Name | Description |
+|---|------|-------------|
+| 1 | **Rainbow** | All 20 LEDs show the same colour; the hue cycles slowly through the full spectrum (~20 s per revolution) |
+| 2 | **Row sweep** | One row lights up at a time and sweeps downward; the hue drifts continuously |
+| 3 | **Column sweep** | One column lights up at a time and sweeps rightward |
+| 4 | **Stars** | 8 LEDs at random positions fade in with a random colour then fade out; when a star dies a new one appears elsewhere |
+| 5 | **Breathing** | All LEDs pulse with a triangular brightness envelope (~5 s per breath); the hue shifts slowly between cycles |
+| 6 | **Rainbow rows** | Each row shows a different hue (90° apart on the colour wheel); all hues advance together |
+| 7 | **Wave** | A bright column chases across the grid with a two-column fading trail |
+
+---
+
+## Flash
+
+```bash
+tinygo flash -target=xiao-esp32c3 -stack-size=8KB .
+```
+
+Requires TinyGo ≥ 0.41 and [`tinygo.org/x/drivers`](https://github.com/tinygo-org/drivers) v0.35.
+
+---
+
+## Build
+
+### Step 1 — Bare PCB
+
+The back side of the custom PCB. Footprints for the 20 WS2812 LEDs are arranged in the 4 × 5 grid. 
+
+![Step 1 – bare PCB front](assets/step1.jpg)
+
+---
+
+### Step 2 — Qwiic / StemmaQT connector
+
+We'll start with the SMD Qwiic / StemmaQT connector since it's the trickiest to solder. It is not really needed, but a cool way to extend the board with sensors. Use the help of some flux if needed.
+
+![Step 2 – qwiic stemmaqt](assets/step2.jpg)
+
+---
+
+### Step 3 — Soldering the button
+
+The tactile switch is soldered to its footprint on top of the board. Easier than the stemmaQT.
+
+![Step 3 – soldering button](assets/step3.jpg)
+
+---
+
+### Step 4 — PCB fully populated
+
+All 20 LEDs and the button in place. The XIAO BLE/RP2040/ESP32C3/... plugs in on the left edge. It's the easier one to do, and the last one to be done since it goes over one LED.
+
+![Step 4 – PCB fully populated](assets/step4.jpg)
+
+
+**NOTE**: Make sure all the LEDs are correctly soldered since once we solder the board there's no way to fix the LED behind it.
+---
+
+### Step 5 — PCB seated in the frame
+
+The board drops into the back shell. The silkscreen on the rear shows the Go gopher pattern.
+
+![Step 5 – PCB in frame](assets/step6.jpg)
+
+---
+
+### Step 6 — 3D-printed back cover
+
+The black back shell printed in PLA. The XIAO slides into the slot on the side for USB access. Use 4 screws on the holes.
+
+![Step 6 – back cover](assets/step5.jpg)
+
+
+---
+
+### Step 7 — Frosted diffuser panel
+
+A white PLA diffuser snaps onto the front of the frame to spread the light evenly across the grid. You could print different models of the diffuser!
+
+![Step 7 – diffuser panel](assets/step7.jpg)
+
+---
+
+### Step 8 — Finished
+
+Fully assembled and running. The diffuser softens each LED point into a smooth glow.
+
+![Step 8 – finished, lit](assets/step8.jpg)
+
+---
+
+## Showroom
+
+![Video 1](assets/videogif1.gif)
+
+![Video 2](assets/videogif2.gif)
+
+
+## License
+
+[MIT](LICENSE)

main.go

@@ -1,12 +1,3 @@
-// Hikari – WS2812 LED effects for XIAO ESP32C3
-//
-// Hardware:
-//   D6 (GPIO21) – WS2812 data (20 LEDs, 4 rows × 5 columns)
-//   D3 (GPIO5)  – Pushbutton, active-low (internal pull-up)
-//
-// Flash:
-//   tinygo flash -target=xiao-esp32c3 -stack-size=8KB .
-
 package main
 
 import (
@@ -17,8 +8,6 @@ import (
 	"tinygo.org/x/drivers/ws2812"
 )
 
-// ─── constants ────────────────────────────────────────────────────────────────
-
 const (
 	numLEDs    = 20
 	numRows    = 4
@@ -26,26 +15,32 @@ const (
 	numEffects = 7
 	frameDelay = 20 * time.Millisecond
 	debounce   = 200 * time.Millisecond
+	numStars   = 8
+	starStep   = 7
 )
 
-// Pin assignments for XIAO ESP32C3
 const (
-	pinLED = machine.D6 // WS2812 data line
-	pinBtn = machine.D3 // Button (pulled up, LOW when pressed)
+	pinLED = machine.D6
+	pinBtn = machine.D3
 )
 
-// ─── globals ──────────────────────────────────────────────────────────────────
+type star struct {
+	pos uint8 // LED index
+	hue uint8 // colour on the wheel
+	br  uint8 // current brightness (0-255)
+	dir int8  // +1 rising, -1 falling
+}
 
 var (
+	starList [numStars]star
+	starsOK  bool
 	leds     [numLEDs]color.RGBA
 	strip    ws2812.Device
 
 	// xorshift32 PRNG – seeded with a compile-time constant
-	rngState uint32 = 0xCAFE1234
+	rngState uint32 = 0xDEADBEEF
 )
 
-// ─── colour helpers ───────────────────────────────────────────────────────────
-
 // wheel maps 0-255 → smooth full-hue spectrum (R→G→B→R)
 func wheel(pos uint8) color.RGBA {
 	switch {
@@ -87,9 +82,7 @@ func rand() uint32 {
 	return rngState
 }
 
-// ─── effect 1 – Rainbow ───────────────────────────────────────────────────────
-// All LEDs show the same hue; the hue cycles slowly through the full spectrum.
-
+// effectRainbow cycles through all the colors slowly
 func effectRainbow(step uint32) {
 	c := wheel(uint8(step >> 2)) // full cycle ≈ 20 s
 	for i := range leds {
@@ -97,9 +90,7 @@ func effectRainbow(step uint32) {
 	}
 }
 
-// ─── effect 2 – Row sweep ─────────────────────────────────────────────────────
-// One row at a time is lit; the active row sweeps downward while the hue drifts.
-
+// effectRowSweep lit a row at a time, the color/hue changes
 func effectRowSweep(step uint32) {
 	clear()
 	row := int(step/40) % numRows
@@ -109,9 +100,7 @@ func effectRowSweep(step uint32) {
 	}
 }
 
-// ─── effect 3 – Column sweep ──────────────────────────────────────────────────
-// One column at a time is lit; the active column sweeps rightward.
-
+// effectColSweep lit a column at a time, the color/hue changes
 func effectColSweep(step uint32) {
 	clear()
 	col := int(step/40) % numCols
@@ -121,38 +110,20 @@ func effectColSweep(step uint32) {
 	}
 }
 
-// ─── effect 4 – Stars ─────────────────────────────────────────────────────────
-// Random LEDs glow in random colours then fade out, one by one.
-
-type star struct {
-	pos uint8 // LED index
-	hue uint8 // colour on the wheel
-	br  uint8 // current brightness (0-255)
-	dir int8  // +1 rising, -1 falling
-}
-
-const (
-	numStars = 8
-	starStep = 7 // brightness change per frame (~35 frames to full glow)
-)
-
-var (
-	starList [numStars]star
-	starsOK  bool
-)
-
+// initStars resets the data for the stars effect
 func initStars() {
 	for i := range starList {
 		starList[i] = star{
 			pos: uint8(rand() % numLEDs),
 			hue: uint8(rand()),
-			br:  uint8(i * (255 / numStars)), // stagger so they don't sync
+			br:  uint8(i * (255 / numStars)),
 			dir: 1,
 		}
 	}
 	starsOK = true
 }
 
+// effectStarts lit random LEDs and dimm them slowly
 func effectStars(_ uint32) {
 	if !starsOK {
 		initStars()
@@ -181,30 +152,24 @@ func effectStars(_ uint32) {
 	}
 }
 
-// ─── effect 5 – Breathing ─────────────────────────────────────────────────────
-// All LEDs pulse in unison with a triangular brightness envelope; the hue
-// drifts imperceptibly slowly.
-
+// effectBreathing shows classic breathing effect
 func effectBreathing(step uint32) {
-	t := uint8(step) // 0-255, period = 256 frames ≈ 5 s
+	t := uint8(step)
 	var br uint8
 	if t < 128 {
-		br = t * 2 // 0 → 254
+		br = t * 2
 	} else {
-		br = (255 - t) * 2 // 254 → 0
+		br = (255 - t) * 2
 	}
-	hue := uint8(step >> 7) // hue changes once per breath cycle
+	hue := uint8(step >> 7)
 	for i := range leds {
 		leds[i] = dim(wheel(hue), br)
 	}
 }
 
-// ─── effect 6 – Rainbow rows ──────────────────────────────────────────────────
-// Each row shows a distinct hue (separated by 64/256 of the wheel); all hues
-// advance together, making the whole grid slowly rotate through colours.
-
+// effectRainbowRows shows a different color in each row and change its hue slowly
 func effectRainbowRows(step uint32) {
-	base := uint8(step >> 2) // same drift speed as effect 1
+	base := uint8(step >> 2)
 	for row := 0; row < numRows; row++ {
 		c := wheel(base + uint8(row*64))
 		for col := 0; col < numCols; col++ {
@@ -213,15 +178,12 @@ func effectRainbowRows(step uint32) {
 	}
 }
 
-// ─── effect 7 – Column wave ───────────────────────────────────────────────────
-// A bright column chases across the grid with a fading two-column tail.
-
+// effectWave runs a cool wave effect
 func effectWave(step uint32) {
 	clear()
-	head := int(step/8) % numCols // advances one column every 8 frames ≈ 160 ms
+	head := int(step/8) % numCols
 	hue := uint8(step >> 1)
 
-	// Brightness per distance behind the head
 	bri := [numCols]uint8{255, 110, 35, 0, 0}
 
 	for col := 0; col < numCols; col++ {
@@ -236,14 +198,10 @@ func effectWave(step uint32) {
 	}
 }
 
-// ─── main ─────────────────────────────────────────────────────────────────────
-
 func main() {
-	// Initialise WS2812
 	pinLED.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	strip = ws2812.New(pinLED)
 
-	// Initialise button with internal pull-up
 	pinBtn.Configure(machine.PinConfig{Mode: machine.PinInputPullup})
 
 	var (
@@ -254,16 +212,14 @@ func main() {
 	)
 
 	for {
-		// ── Button: detect falling edge with debounce ─────────────────────
-		btnDown := !pinBtn.Get() // LOW = pressed (active-low)
+		btnDown := !pinBtn.Get()
 		if btnDown && !prevBtn && time.Since(lastPress) > debounce {
 			effect = (effect + 1) % numEffects
 			lastPress = time.Now()
-			starsOK = false // force stars to reinitialise next time
+			starsOK = false
 		}
 		prevBtn = btnDown
 
-		// ── Render current effect ─────────────────────────────────────────
 		switch effect {
 		case 0:
 			effectRainbow(step)