From 4fd9e1b3e9467670b9af9d76f47cdacf18a93951 Mon Sep 17 00:00:00 2001
From: Dejvino <dejvino@gmail.com>
Date: Fri, 20 Feb 2026 07:13:16 +0100
Subject: [PATCH] Fix neopixel flickering

---
 README.md     | 12 +++++++++---
 UIManager.cpp |  3 ++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index ba3b60b..ae2b67f 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ Make sure to establish a **common ground** by connecting the ground from your ex
 | DT | GP13 (Pin 17) | Encoder Data |
 | SW | GP14 (Pin 19) | Encoder Switch |
 | **WS2812B 8x8 Matrix**| | |
-| DIN (Data In) | GP16 (Pin 21) | NeoPixel Data |
+| DIN (Data In) | GP2 (Pin 4) | NeoPixel Data |
 | 5V / VCC | External 5V Supply `+` | **External 5V Power** |
 | GND | External 5V Supply `-` | **External Power Ground** |
 | | GND (Pin 18) | **Common Ground with Pico** |
@@ -50,7 +50,7 @@ Make sure to establish a **common ground** by connecting the ground from your ex
 | TX (MIDI OUT) | GP0 (Pin 1) | To DIN Pin 5 (via 220Ω) |
 
 **MIDI Hardware Note**:
-*   **MIDI OUT**: Connect **GP0** to DIN Pin 5 via a 220Ω resistor. Connect DIN Pin 4 to +5V via a 220Ω resistor. Connect DIN Pin 2 to GND.
+*   **MIDI OUT**: Connect **GP0** to DIN Pin 5 via a 220Ω resistor. Connect DIN Pin 4 to 3.3V (3V3) via a 220Ω resistor. Connect DIN Pin 2 to GND.
 
 Once everything is wired up, you can upload the code and your tracker should be ready to go!
 
@@ -91,4 +91,10 @@ For a more integrated build that can fit inside an enclosure, you can use a Lith
 *   **Navigation**: Rotate the encoder to move between steps.
 *   **Edit Mode**: Short press the encoder button to toggle Edit Mode. Rotate to change the note.
 *   **Playback**: Long press the encoder button (> 0.6s) to Start/Stop playback.
-*   **MIDI**: The device sends MIDI notes via the Hardware Serial (DIN) port on GP0.
\ No newline at end of file
+*   **MIDI**: The device sends MIDI notes via the Hardware Serial (DIN) port on GP0.
+
+## Troubleshooting
+- NeoPixel LEDs randomly lighting full bright white? Try a different pin. E.g. pin 16 has some noise that messes with the precise timing of the NeoPixel.
+- MIDI signal not accepted by a device? Check that you're using 3.3V and not 5V. Some devices accept it, others don't. MIDI uses 3V3.
+- Device freezing and restarting? Watchdog detected a deadlock and restarted the system. Check for `midi.lock()` & `midi.unlock()` called *exactly once* one after another. Calling lock twice causes a deadlock.
+- NeoPixel not lighting up? Connect it to an external power source strong enough to drive 3A. Don't power it directly from the Pico.
diff --git a/UIManager.cpp b/UIManager.cpp
index 4a48194..991a1ce 100644
--- a/UIManager.cpp
+++ b/UIManager.cpp
@@ -7,7 +7,7 @@
 #define SCREEN_HEIGHT 64
 #define OLED_RESET    -1 
 #define SCREEN_ADDRESS 0x3C
-#define PIN_NEOPIXEL 16
+#define PIN_NEOPIXEL 2
 #define NUM_PIXELS   64
 
 UIManager ui;
@@ -29,6 +29,7 @@ void UIManager::begin() {
     display.display();
 
     // Setup NeoPixel Matrix
+    pixels.setPin(PIN_NEOPIXEL);
     pixels.begin();
     pixels.setBrightness(40);
     pixels.clear();