Etch-A-Sketch mode

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+*.xcodeproj

SCTVcode/SCTVcode.ino

@@ -43,7 +43,7 @@
 // V 1.1.1 05/14/22 DF  Adding SCT-A board with Teensy 4.1, different I/O pins
 // V 1.2.0 12/14/22 DF  Updated USB host library local copy
 
-char versionNo[]  = "Version 1.2.0\n";
+char versionNo[]  = "Version 1.2.0sf\n";
 
 // THINGS TO DO
 
@@ -111,7 +111,7 @@ char versionNo[]  = "Version 1.2.0\n";
 
 // SCTV-E up has Teensy 4.1 and SPI DAC, SCTV-D down use Teensy 3.6 with internal DAC
 // Comment out the line below if compiling for board with Teensy 3.6 (SCTV-A..D)
-#define SCTVE
+// #define SCTVE
 
 // The SCT has the Teensy 4.1 and external DAC, it also has different pins 
 // defined for many functions. 

SCTVcode/te_etchasketch.ino

@@ -0,0 +1,90 @@
+// ------------------------------ Etch-A-Sketch -------------------------------
+
+struct Point {
+    int x;
+    int y;
+};
+
+const int MAX_SEGMENTS = 1000;
+const int END_TOKEN = -9999;
+
+Point* segments;
+Point* segment;
+Point direction;
+int x, y;
+
+struct item etchList[] = {};
+
+void getControlsXY() {
+	// read the position controls for X,Y, and average for smooth readings
+ 	for (int i = 0; i < 40; i++) {
+ 		x += analogRead(XPosPin) - 512;	// read position controls
+ 		y += analogRead(YPosPin) - 512;	// make bipolar so midpoint is nominal
+ 	}
+    // Center in the display area, scale for correct overshoot
+    x = x / 20;
+    y = y / 20;
+}
+
+void resetEtchASketch() {
+    if (segments == 0) {
+        segments = (Point*)malloc(sizeof(Point) * (MAX_SEGMENTS+2));
+    }
+    direction.x = 0;
+    direction.y = 0;
+
+    getControlsXY();
+    segment = segments;
+    segment[0].x = x;
+    segment[0].y = y;
+    segment[1].x = END_TOKEN;
+}
+
+void etchASketch() {
+    if (pushed) {
+        // selector button pushed: erase all traces
+        resetEtchASketch();
+        pushed = false;
+    }
+
+    // read X,Y control knobs and extend trace segments to it
+    getControlsXY();
+    int dx = x - segment->x;    
+    int dy = y - segment->y;
+    int ds = sqrt((dx*dx + dy*dy) * 64);
+    if (ds != 0) {
+        // Serial.printf("Etch: xy=(%d,%d), ds=%d\n", x, y, ds);
+        // int n = segment - segments;
+        // Serial.printf(" dir=(%d,%d) %d segs, (%d,%d)-(%d,%d)\n",
+        //               direction.x, direction.y, n, segment[0].x, segment[0].y, x, y);
+        // normalized direction vector for this segment
+        dx = 64 * dx / ds;
+        dy = 64 * dy / ds;
+        int diff = abs(dx - direction.x) + abs(dy - direction.y);
+        if (diff > 2 && segment < segments + MAX_SEGMENTS) {
+            // have changed direction: start new segment
+            // Serial.printf(" dx,dy=(%d,%d), ds=%d\n", dx, dy, ds);
+            direction.x = dx;
+            direction.y = dy;
+            segment++;
+            segment[0].x = x;
+            segment[0].y = y;
+            segment[1].x = END_TOKEN;
+        } else {
+            // else just extend last segment
+            segment->x = x;
+            segment->y = y;
+        }
+    }
+
+    // draw current list of trace segments
+    Scale = 1;
+    Shape = lin;
+    for (Point* seg = segments; seg[1].x != END_TOKEN; seg++) {
+        XStart = seg[0].x;
+        YStart = seg[0].y;
+        XEnd = seg[1].x;
+        YEnd = seg[1].y;
+        DoSeg();    // draw a line from (XStart,YStart) to (XEnd,YEnd)
+    }
+}

SCTVcode/w_menus.ino

@@ -83,7 +83,7 @@ struct item locMenu[] = {
 // This is the clock display option list
 
 // If Clock is zero; then draw hands
-const int NClks = 8;    // number of clock faces to choose from (splash doesn't count)
+const int NClks = 9;    // number of clock faces to choose from (splash doesn't count)
 
 // list of clock face draw lists
 item * ClkList[] = 
@@ -97,6 +97,7 @@ item * ClkList[] =
     time6dList,  // 6 digit digital clock with date
     haikuList,   // some poetry at random
  //   flwList,     // four letter words at random
+    etchList,    // Etch-A-Sketch
     splashList,  // splash screen vanishes when knob touched
     0};
 // -------------------------- Menu navigation -----------------------

SCTVcode/z_main.ino

@@ -146,8 +146,8 @@ void loop()
       myGps.encode(userial.read());
   }
 
-  if ((theClock != 1) && (theClock != 2))  // Pong and Tetris use position controls as paddles
-  {
+  if ((theClock != 1) && (theClock != 2) && (theClock != 8))  // Pong, Tetris, and Etch-A-Sketch
+  {                                                           // use position controls as paddles
     xPos = yPos = 0;
     for (i=0;i<40;i++) {
       xPos += analogRead(XPosPin) - 512;   // read the position controls
@@ -189,17 +189,23 @@ void loop()
       {
         reset_tetris();
       }
+      if (theClock == 8)
+      {
+        resetEtchASketch();
+      }
       EncDir = 0;
     }
     whichList = ClkList[theClock];       // point to the clock drawlist we are displaying now
     if (theClock == 0) DrawClk();        // clock 0 has hands to draw
     if (theClock == 1) doPong();         // clock 1 is Pong
     if (theClock == 2) drawTetris();     // clock 2 is Tetris
-    if (pushed) 
+    if (theClock == 8) etchASketch();    // clock 8 is Etch-A-Sketch
+    if (theClock != 8 && pushed)
     {
       whichList = mainMenu;
       HotItem = 1;
       InMenu = true;
+      Serial.printf("Button pushed. theClock=%d\n", theClock);
     }
   }