Add matrix driver sample

Author: cartheur

ls39f.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Device.I2c;
+using System.Threading;
+
+class Program
+{
+    // I2C address (default for IS31FL3731/IS31FL3741, check your board)
+    const int I2cAddress = 0x74;
+    // Register addresses
+    const byte PageSelect = 0xFD; // Function register page select
+    const byte ConfigReg = 0x00;  // Configuration register
+    const byte LedControlBase = 0x00; // LED control base (Page 0)
+
+    // Matrix dimensions
+    const int Width = 13;  // Columns
+    const int Height = 9;  // Rows
+
+    static void Main()
+    {
+        // Open I2C bus 1 (Raspberry Pi default)
+        I2cConnectionSettings settings = new(1, I2cAddress);
+        using I2cDevice device = I2cDevice.Create(settings);
+
+        // Initialize the chip
+        Initialize(device);
+
+        // Turn on some LEDs (e.g., at (0,0), (6,4), (12,8))
+        SetLedState(device, 0, 0, true);  // Top-left
+        SetLedState(device, 6, 4, true);  // Middle-ish
+        SetLedState(device, 12, 8, true); // Bottom-right
+
+        Console.WriteLine("LEDs on! Press Ctrl+C to exit.");
+        Thread.Sleep(Timeout.Infinite);
+    }
+
+    static void Initialize(I2cDevice device)
+    {
+        // Select Function Register page
+        device.Write(new byte[] { PageSelect, 0x0B });
+        // Set to normal operation (disable shutdown)
+        device.Write(new byte[] { ConfigReg, 0x01 });
+
+        // Select LED Control page (Page 0)
+        device.Write(new byte[] { PageSelect, 0x00 });
+        // Enable LEDs for 13x9 matrix (117 LEDs, 15 bytes needed)
+        for (byte i = 0; i < 15; i++) // 117 bits = 14.625 bytes, round up to 15
+        {
+            device.Write(new byte[] { (byte)(LedControlBase + i), 0xFF });
+        }
+    }
+
+    static void SetLedState(I2cDevice device, int x, int y, bool state)
+    {
+        if (x < 0 || x >= Width || y < 0 || y >= Height)
+        {
+            Console.WriteLine($"Invalid coordinates: ({x}, {y})");
+            return;
+        }
+
+        // Map 13x9 coordinates to LED register
+        int ledIndex = x + (y * Width); // Linear index for 13x9
+        byte register = (byte)(LedControlBase + (ledIndex / 8));
+        byte bit = (byte)(ledIndex % 8);
+        byte mask = (byte)(1 << bit);
+
+        // Read current state, modify, write back
+        byte[] readBuffer = new byte[1];
+        device.WriteRead(new byte[] { register }, readBuffer);
+        byte current = readBuffer[0];
+        byte newValue = state ? (byte)(current | mask) : (byte)(current & ~mask);
+        device.Write(new byte[] { register, newValue });
+    }
+}