Cymbal pads send up/down so RB3 is playable

MockBand.ino

@@ -122,30 +122,40 @@ void loop() {
     }
     next = now + UPDATE_INTERVAL_MS;
 
+    //
+    // Calculate and send an HID update
+    //
+    
     buttonState.buttons = (buttons & 0b1100111111);     // +-..!OYRGB
 #ifdef GUITAR
     buttonState.buttons |= (buttons >> 10) & 0b11111;   // Solo keys
     bitWrite(buttonState.buttons,  6, buttons & (0b11111 << 10));  // Solo modifier
+
+    if (bitRead(buttons, 6)) {
+      buttonState.hatAndConstant = 0; // up
+    } else if bitRead(buttons, 7) { // 
+      buttonState.hatAndConstant = 4; // down
+    } else {
+      buttonState.hatAndConstant = 8; // nothing
+    }
 #else // DRUMS
     buttonState.buttons |= (buttons >> 10) & 0b01011;   // Cymbals
     bitWrite(buttonState.buttons, 10, buttons & (0b01111 <<  0));  // Drum pad modifier
     bitWrite(buttonState.buttons, 11, buttons & (0b01011 << 10));  // Cymbals modifier
     buttonState.axis[3] = bitRead(buttons, 12)?255:0;   // High hat
+
+    // Use the cymbals for up and down, since I don't have a D-pad
+    if bitRead(buttons, 13) {
+      buttonState.hatAndConstant = 0; // up
+    } else if bitRead(buttons, 10) {
+      buttonState.hatAndConstant = 4; // down
+    } else {
+      buttonState.hatAndConstant = 8; // nothing
+    }
 #endif
 
     // D-pad would go here if I ever implemented that:
     // nothing seems to actualy need it.
-    //
-    // I don't understand why any rational engineer would have specified this algorithm.
-    if (bitRead(buttons, 6)) {
-      buttonState.hatAndConstant = 0x00; // up
-    } else if bitRead(buttons, 7) { // 
-      buttonState.hatAndConstant = 0x04; // down
-    } else {
-      buttonState.hatAndConstant = 0x08; // nothing
-    }
-    // left: 0x06
-    // right: 0x02
 
 #ifdef WAMMY
     buttonState.axis[2] = analogRead(ANALOG_WAMMY) / 4; // Wammy bar

NOTES.md

@@ -37,3 +37,37 @@ in addition to the switch bouncing,
 the stick was bouncing on the rubber pad.
 I settled on a 40ms silence window as feeling pretty good.
 You can adjust this if you want to.
+
+
+Gamepad Buttons
+---------------
+
+The `buttons` struct member is a bitmap,
+each bit mapping to one of the 12 buttons reported through HID.
+Here's what each bit means:
+
+*  0: Blue
+*  1: Green
+*  2: Red
+*  3: Yellow
+*  4: Orange
+*  5: Tilt Switch / 2x kick
+*  6: Solo modifier (second row of buttons on guitar)
+*  7: ?
+*  8: Minus
+*  9: Plus
+* 10: Drum pad modifier?
+* 11: Cymbal modifier?
+* 12: ?
+
+
+hatAndConstant
+--------------
+
+I don't get this, but here's what the values mean:
+
+* 2: right
+* 6: left
+* 0: up
+* 4: down
+* 8: nothing