[+] Keyboard lights

firmware/src/config.h

@@ -24,6 +24,8 @@ const int MUX_SEL_OUT[NUM_MUX_SEL] = {14, 13, 12, 11};
 const int LK_PIN = 2;
 const int LK_LIGHTS_PER_METER = 60;
 const float LK_NUM_METERS = 2;
+const int LK_KEY_SPACING_MM = 7;
+const int LK_KEY_LEN_MM = 15;
 const int LK_NUM_LIGHTS = (int) round(LK_LIGHTS_PER_METER * LK_NUM_METERS);
 
 // ========================================

firmware/src/keyboard_lights.cpp

@@ -0,0 +1,46 @@
+//
+// Created by Hykilpikonna on 4/21/23.
+//
+
+#include "config.h"
+#include "Adafruit_NeoPixel.h"
+
+class KeyboardLights
+{
+private:
+    Adafruit_NeoPixel led_key;
+
+public:
+    KeyboardLights() : led_key(4, LK_PIN, NEO_GRB + NEO_KHZ800) {}
+
+    void begin()
+    {
+        led_key.begin();
+    }
+
+    /**
+     * Convert a key index to a light index
+     *
+     * The light strip's spacing doesn't match the keyboard's spacing, so we need to convert.
+     * Light strip info are defined by LK_LIGHTS_PER_METER and LK_NUM_LIGHTS.
+     * Key spacing info are defined by LK_KEY_SPACING_MM and LK_KEY_LEN_MM.
+     *
+     * @param key Key index from 0 to 60
+     * @return Light index
+     */
+    static int keyToLight(int key)
+    {
+        return (int) (key * LK_KEY_SPACING_MM / LK_KEY_LEN_MM * LK_LIGHTS_PER_METER);
+    }
+
+    void hit(int key)
+    {
+        // 1. Calculate the starting index
+        int start = keyToLight(key);
+
+        Serial.printf("Key %d -> Light %d\n", key, start);
+
+        // 2. Set the color of the lights
+        led_key.setPixelColor(start, Adafruit_NeoPixel::ColorHSV(0, 255, 255));
+    }
+};

firmware/src/main.cpp

@@ -4,6 +4,7 @@
 #include "main.h"
 #include "utils.h"
 #include "panel.cpp"
+#include "keyboard_lights.cpp"
 
 u32 lasts[NUM_NOTES];  // variable to store the value coming from the sensor
 u64 last_hit_times[NUM_NOTES];