Ajout README

README.md

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+# Introduction
+
+This is the source files folder for the EasyDccMouse.
+
+EasyDccMouse is a system to remote control DCC scale locomotive, it is based on a ESP32 with tft display, touch screen, encoder and battery.
+
+EasyDccMouse sends actions to a DCC centrale station.
+
+
+```
++------------------------------------------------------+
+| [O]  [⇄]  [ID]  [⚡]                                 |  <-- Header with 4 icons:
+|  ON   Dir   DCC   Power                             |      [O] Status (ON/OFF)
+|                                                     |      [⇄] Direction (Forward/Reverse)
+|   [================== Train ===================]     |      [ID] DCC id
+|                                                     |      [⚡] Power/Connection
+|   |██████████████████████████████████████████|      |  <-- Model picture (190x40 px)
+|                                                     |
+|                ___                                   |
+|             .-'   '-.                                |
+|           .'         '.                              |
+|          /             \                             |
+|         |   /\     /\   |                            |  <-- Speedometer (arc + needle)
+|         |  /  \   /  \  |                            |
+|         | /    \_/    \ |                            |
+|         |/             \|                            |
+|         '---------------'                            |
+|             |    |                                   |
+|             |    |                                   |
+|            Needle                                   |
+|                                                     |
+|  [F1] [F2] [F3] [F4] [F5] [F6] [F7] [F8]            |  <-- Function pad (row 1)
+|  [F9] [F10][F11][F12][F13][F14][F15][F16]           |  <-- Function pad (row 2)
++------------------------------------------------------+
+```
+
+# Implementation
+
+
+## How to draw speedometer with arc and needle on my TFT display?
+
+To draw an arc-style speedometer with a moving needle on your TFT display (e.g., ILI9341), you can use the TFT_eSPI library. Here’s a step-by-step example:
+
+1. **Draw the arc:**
+	- Use `drawArc()` or draw multiple short lines to approximate an arc.
+	- Example: Draw an arc from 135° to 45° (like a semicircle at the bottom).
+
+2. **Draw the needle:**
+	- Calculate the angle for the needle based on the speed value.
+	- Use `drawLine()` from the center of the arc to the edge at the calculated angle.
+
+3. **Display the speed value:**
+	- Use `setCursor()` and `print()` to show the numeric speed.
+
+**Example code:**
+```cpp
+#include <TFT_eSPI.h>
+#include <math.h>
+
+TFT_eSPI tft = TFT_eSPI();
+
+void drawSpeedometer(int speed) {
+  int cx = 120, cy = 120, r = 80; // Center and radius
+  int minAngle = 135, maxAngle = 45; // Degrees
+  int minSpeed = 0, maxSpeed = 100;
+
+  // Draw arc (approximate with lines)
+  for (int a = minAngle; a >= maxAngle; a -= 3) {
+	 float rad = a * 3.14159 / 180.0;
+	 int x1 = cx + (r - 10) * cos(rad);
+	 int y1 = cy + (r - 10) * sin(rad);
+	 int x2 = cx + r * cos(rad);
+	 int y2 = cy + r * sin(rad);
+	 tft.drawLine(x1, y1, x2, y2, TFT_WHITE);
+  }
+
+  // Draw needle
+  float angle = minAngle - (float)(speed - minSpeed) / (maxSpeed - minSpeed) * (minAngle - maxAngle);
+  float rad = angle * 3.14159 / 180.0;
+  int nx = cx + (r - 20) * cos(rad);
+  int ny = cy + (r - 20) * sin(rad);
+  tft.drawLine(cx, cy, nx, ny, TFT_RED);
+
+  // Draw speed value
+  tft.setCursor(cx - 20, cy + 30);
+  tft.setTextColor(TFT_WHITE, TFT_BLACK);
+  tft.setTextSize(2);
+  tft.printf("%d", speed);
+}
+```
+
+**Tips:**
+- Clear the previous needle before drawing a new one for smooth animation.
+- Adjust `cx`, `cy`, and `r` for your display size.
+- You can enhance the arc with tick marks and labels for a more realistic look.